From nobody Mon Sep 15 20:41:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1EC34C4332F for ; Wed, 9 Nov 2022 11:51:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230340AbiKILvD (ORCPT ); Wed, 9 Nov 2022 06:51:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229956AbiKILu7 (ORCPT ); Wed, 9 Nov 2022 06:50:59 -0500 Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C86571C126 for ; Wed, 9 Nov 2022 03:50:57 -0800 (PST) Received: by mail-pj1-x1032.google.com with SMTP id q1-20020a17090a750100b002139ec1e999so1664003pjk.1 for ; Wed, 09 Nov 2022 03:50:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Rh+SDXfLWIiVuWyo4HoAJrWsmodyn/AWQvoZfxriBos=; b=lg6XyX6EZCivsCvPp8F8Rk6MdzQU/pZ+5B2QkiAgYr9uOdlZI8FpXbs7pOWgOxaC27 Ha1xmVXR8wH+qelEb8KwopTpXVQWggLiLk+qU61M2tVtEFOJ5v89IAhpSrgx7rGO6XZ+ rZpDnypFeVyF+dtrNl7DFImc7xwrivwZmV2cU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Rh+SDXfLWIiVuWyo4HoAJrWsmodyn/AWQvoZfxriBos=; b=uWIAKB7WRY04P4cHtI/pXPlm2LF0ITeI/OvxEnBI+ifCpqVuifLd3Uuv4BtDSmd4yN pw7kRFLW1y4wiMJWh7b3D7WhOvic5NnRJtMZf8W9DoOWftQMlQdirJturA6HWQWlGq4Y uZTbjm/d24ejQRkD+grdy2Xl2YFv1TX036NOftuESZpdKrXGKZHX60Jjgys/PqQu+aPq nPy3ZlFYGXkPIoQOIujNrV/qNZwfEFGYXeypu3limt17oGQ+x4YSi+aQwDJmZ0a6ma+8 tmcwe72433+x/xfrOhOk+9tgV4qjd/EpAnYLBTRQrjKYIcysAuxtThmvLcfaqr2dG0qb x7/Q== X-Gm-Message-State: ACrzQf2dwkBflrSrpRp5iDL036kwnkyY4WT95UyVrHDx5MvzM+o7Dtht yJHDu7bFnpEM+fDvz5txRmxs3g== X-Google-Smtp-Source: AMsMyM5ap4cnFJgQIJB7Qd+V3iIFej6hsh6xDMaaJARu3Yb9BdtCqFiYi2/jyzLy7wFP2TGgAFTMcA== X-Received: by 2002:a17:903:11cd:b0:170:cde8:18b7 with SMTP id q13-20020a17090311cd00b00170cde818b7mr44212976plh.165.1667994657224; Wed, 09 Nov 2022 03:50:57 -0800 (PST) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:61f1:44d3:3f47:2cdb]) by smtp.gmail.com with ESMTPSA id f5-20020a655505000000b00434760ee36asm7292311pgr.16.2022.11.09.03.50.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Nov 2022 03:50:56 -0800 (PST) From: Sergey Senozhatsky To: Minchan Kim , Andrew Morton Cc: Nitin Gupta , Suleiman Souhlal , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sergey Senozhatsky Subject: [PATCHv5 01/13] zram: Preparation for multi-zcomp support Date: Wed, 9 Nov 2022 20:50:35 +0900 Message-Id: <20221109115047.2921851-2-senozhatsky@chromium.org> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <20221109115047.2921851-1-senozhatsky@chromium.org> References: <20221109115047.2921851-1-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The patch turns compression streams and compressor algorithm name struct zram members into arrays, so that we can have multiple compression streams support (in the next patches). The patch uses a rather explicit API for compressor selection: - Get primary (default) compression stream zcomp_stream_get(zram->comps[ZRAM_PRIMARY_COMP]) - Get secondary compression stream zcomp_stream_get(zram->comps[ZRAM_SECONDARY_COMP]) We use similar API for compression streams put(). At this point we always have just one compression stream, since CONFIG_ZRAM_MULTI_COMP is not yet defined. Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- drivers/block/zram/zcomp.c | 6 +-- drivers/block/zram/zcomp.h | 2 +- drivers/block/zram/zram_drv.c | 90 +++++++++++++++++++++++++---------- drivers/block/zram/zram_drv.h | 14 +++++- 4 files changed, 80 insertions(+), 32 deletions(-) diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c index 0916de952e09..55af4efd7983 100644 --- a/drivers/block/zram/zcomp.c +++ b/drivers/block/zram/zcomp.c @@ -206,7 +206,7 @@ void zcomp_destroy(struct zcomp *comp) * case of allocation error, or any other error potentially * returned by zcomp_init(). */ -struct zcomp *zcomp_create(const char *compress) +struct zcomp *zcomp_create(const char *alg) { struct zcomp *comp; int error; @@ -216,14 +216,14 @@ struct zcomp *zcomp_create(const char *compress) * is not loaded yet. We must do it here, otherwise we are about to * call /sbin/modprobe under CPU hot-plug lock. */ - if (!zcomp_available_algorithm(compress)) + if (!zcomp_available_algorithm(alg)) return ERR_PTR(-EINVAL); =20 comp =3D kzalloc(sizeof(struct zcomp), GFP_KERNEL); if (!comp) return ERR_PTR(-ENOMEM); =20 - comp->name =3D compress; + comp->name =3D alg; error =3D zcomp_init(comp); if (error) { kfree(comp); diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h index 40f6420f4b2e..cdefdef93da8 100644 --- a/drivers/block/zram/zcomp.h +++ b/drivers/block/zram/zcomp.h @@ -27,7 +27,7 @@ int zcomp_cpu_dead(unsigned int cpu, struct hlist_node *n= ode); ssize_t zcomp_available_show(const char *comp, char *buf); bool zcomp_available_algorithm(const char *comp); =20 -struct zcomp *zcomp_create(const char *comp); +struct zcomp *zcomp_create(const char *alg); void zcomp_destroy(struct zcomp *comp); =20 struct zcomp_strm *zcomp_stream_get(struct zcomp *comp); diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 966aab902d19..5371ed63c785 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1007,36 +1007,53 @@ static ssize_t comp_algorithm_show(struct device *d= ev, struct zram *zram =3D dev_to_zram(dev); =20 down_read(&zram->init_lock); - sz =3D zcomp_available_show(zram->compressor, buf); + sz =3D zcomp_available_show(zram->comp_algs[ZRAM_PRIMARY_COMP], buf); up_read(&zram->init_lock); =20 return sz; } =20 +static void comp_algorithm_set(struct zram *zram, u32 prio, const char *al= g) +{ + /* Do not kfree() algs that we didn't allocate, IOW the default ones */ + if (zram->comp_algs[prio] !=3D default_compressor) + kfree(zram->comp_algs[prio]); + zram->comp_algs[prio] =3D alg; +} + static ssize_t comp_algorithm_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct zram *zram =3D dev_to_zram(dev); - char compressor[ARRAY_SIZE(zram->compressor)]; + char *compressor; size_t sz; =20 - strscpy(compressor, buf, sizeof(compressor)); + sz =3D strlen(buf); + if (sz >=3D CRYPTO_MAX_ALG_NAME) + return -E2BIG; + + compressor =3D kstrdup(buf, GFP_KERNEL); + if (!compressor) + return -ENOMEM; + /* ignore trailing newline */ - sz =3D strlen(compressor); if (sz > 0 && compressor[sz - 1] =3D=3D '\n') compressor[sz - 1] =3D 0x00; =20 - if (!zcomp_available_algorithm(compressor)) + if (!zcomp_available_algorithm(compressor)) { + kfree(compressor); return -EINVAL; + } =20 down_write(&zram->init_lock); if (init_done(zram)) { up_write(&zram->init_lock); + kfree(compressor); pr_info("Can't change algorithm for initialized device\n"); return -EBUSY; } =20 - strcpy(zram->compressor, compressor); + comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, compressor); up_write(&zram->init_lock); return len; } @@ -1284,7 +1301,7 @@ static int __zram_bvec_read(struct zram *zram, struct= page *page, u32 index, size =3D zram_get_obj_size(zram, index); =20 if (size !=3D PAGE_SIZE) - zstrm =3D zcomp_stream_get(zram->comp); + zstrm =3D zcomp_stream_get(zram->comps[ZRAM_PRIMARY_COMP]); =20 src =3D zs_map_object(zram->mem_pool, handle, ZS_MM_RO); if (size =3D=3D PAGE_SIZE) { @@ -1296,7 +1313,7 @@ static int __zram_bvec_read(struct zram *zram, struct= page *page, u32 index, dst =3D kmap_atomic(page); ret =3D zcomp_decompress(zstrm, src, size, dst); kunmap_atomic(dst); - zcomp_stream_put(zram->comp); + zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]); } zs_unmap_object(zram->mem_pool, handle); zram_slot_unlock(zram, index); @@ -1363,13 +1380,13 @@ static int __zram_bvec_write(struct zram *zram, str= uct bio_vec *bvec, kunmap_atomic(mem); =20 compress_again: - zstrm =3D zcomp_stream_get(zram->comp); + zstrm =3D zcomp_stream_get(zram->comps[ZRAM_PRIMARY_COMP]); src =3D kmap_atomic(page); ret =3D zcomp_compress(zstrm, src, &comp_len); kunmap_atomic(src); =20 if (unlikely(ret)) { - zcomp_stream_put(zram->comp); + zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]); pr_err("Compression failed! err=3D%d\n", ret); zs_free(zram->mem_pool, handle); return ret; @@ -1397,7 +1414,7 @@ static int __zram_bvec_write(struct zram *zram, struc= t bio_vec *bvec, __GFP_HIGHMEM | __GFP_MOVABLE); if (IS_ERR((void *)handle)) { - zcomp_stream_put(zram->comp); + zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]); atomic64_inc(&zram->stats.writestall); handle =3D zs_malloc(zram->mem_pool, comp_len, GFP_NOIO | __GFP_HIGHMEM | @@ -1414,14 +1431,14 @@ static int __zram_bvec_write(struct zram *zram, str= uct bio_vec *bvec, * zstrm buffer back. It is necessary that the dereferencing * of the zstrm variable below occurs correctly. */ - zstrm =3D zcomp_stream_get(zram->comp); + zstrm =3D zcomp_stream_get(zram->comps[ZRAM_PRIMARY_COMP]); } =20 alloced_pages =3D zs_get_total_pages(zram->mem_pool); update_used_max(zram, alloced_pages); =20 if (zram->limit_pages && alloced_pages > zram->limit_pages) { - zcomp_stream_put(zram->comp); + zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]); zs_free(zram->mem_pool, handle); return -ENOMEM; } @@ -1435,7 +1452,7 @@ static int __zram_bvec_write(struct zram *zram, struc= t bio_vec *bvec, if (comp_len =3D=3D PAGE_SIZE) kunmap_atomic(src); =20 - zcomp_stream_put(zram->comp); + zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]); zs_unmap_object(zram->mem_pool, handle); atomic64_add(comp_len, &zram->stats.compr_data_size); out: @@ -1710,6 +1727,20 @@ static int zram_rw_page(struct block_device *bdev, s= ector_t sector, return ret; } =20 +static void zram_destroy_comps(struct zram *zram) +{ + u32 prio; + + for (prio =3D 0; prio < ZRAM_MAX_COMPS; prio++) { + struct zcomp *comp =3D zram->comps[prio]; + + zram->comps[prio] =3D NULL; + if (!comp) + continue; + zcomp_destroy(comp); + } +} + static void zram_reset_device(struct zram *zram) { down_write(&zram->init_lock); @@ -1727,11 +1758,11 @@ static void zram_reset_device(struct zram *zram) /* I/O operation under all of CPU are done so let's free */ zram_meta_free(zram, zram->disksize); zram->disksize =3D 0; + zram_destroy_comps(zram); memset(&zram->stats, 0, sizeof(zram->stats)); - zcomp_destroy(zram->comp); - zram->comp =3D NULL; reset_bdev(zram); =20 + comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, default_compressor); up_write(&zram->init_lock); } =20 @@ -1742,6 +1773,7 @@ static ssize_t disksize_store(struct device *dev, struct zcomp *comp; struct zram *zram =3D dev_to_zram(dev); int err; + u32 prio; =20 disksize =3D memparse(buf, NULL); if (!disksize) @@ -1760,22 +1792,28 @@ static ssize_t disksize_store(struct device *dev, goto out_unlock; } =20 - comp =3D zcomp_create(zram->compressor); - if (IS_ERR(comp)) { - pr_err("Cannot initialise %s compressing backend\n", - zram->compressor); - err =3D PTR_ERR(comp); - goto out_free_meta; - } + for (prio =3D 0; prio < ZRAM_MAX_COMPS; prio++) { + if (!zram->comp_algs[prio]) + continue; + + comp =3D zcomp_create(zram->comp_algs[prio]); + if (IS_ERR(comp)) { + pr_err("Cannot initialise %s compressing backend\n", + zram->comp_algs[prio]); + err =3D PTR_ERR(comp); + goto out_free_comps; + } =20 - zram->comp =3D comp; + zram->comps[prio] =3D comp; + } zram->disksize =3D disksize; set_capacity_and_notify(zram->disk, zram->disksize >> SECTOR_SHIFT); up_write(&zram->init_lock); =20 return len; =20 -out_free_meta: +out_free_comps: + zram_destroy_comps(zram); zram_meta_free(zram, disksize); out_unlock: up_write(&zram->init_lock); @@ -1962,7 +2000,7 @@ static int zram_add(void) if (ret) goto out_cleanup_disk; =20 - strscpy(zram->compressor, default_compressor, sizeof(zram->compressor)); + zram->comp_algs[ZRAM_PRIMARY_COMP] =3D default_compressor; =20 zram_debugfs_register(zram); pr_info("Added device: %s\n", zram->disk->disk_name); diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index a2bda53020fd..7a643c8c38ec 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -89,10 +89,20 @@ struct zram_stats { #endif }; =20 +#ifdef CONFIG_ZRAM_MULTI_COMP +#define ZRAM_PRIMARY_COMP 0U +#define ZRAM_SECONDARY_COMP 1U +#define ZRAM_MAX_COMPS 4U +#else +#define ZRAM_PRIMARY_COMP 0U +#define ZRAM_SECONDARY_COMP 0U +#define ZRAM_MAX_COMPS 1U +#endif + struct zram { struct zram_table_entry *table; struct zs_pool *mem_pool; - struct zcomp *comp; + struct zcomp *comps[ZRAM_MAX_COMPS]; struct gendisk *disk; /* Prevent concurrent execution of device init */ struct rw_semaphore init_lock; @@ -107,7 +117,7 @@ struct zram { * we can store in a disk. */ u64 disksize; /* bytes */ - char compressor[CRYPTO_MAX_ALG_NAME]; + const char *comp_algs[ZRAM_MAX_COMPS]; /* * zram is claimed so open request will be failed */ --=20 2.38.1.431.g37b22c650d-goog From nobody Mon Sep 15 20:41:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48B1FC433FE for ; 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Wed, 09 Nov 2022 03:50:59 -0800 (PST) From: Sergey Senozhatsky To: Minchan Kim , Andrew Morton Cc: Nitin Gupta , Suleiman Souhlal , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sergey Senozhatsky Subject: [PATCHv5 02/13] zram: Add recompression algorithm sysfs knob Date: Wed, 9 Nov 2022 20:50:36 +0900 Message-Id: <20221109115047.2921851-3-senozhatsky@chromium.org> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <20221109115047.2921851-1-senozhatsky@chromium.org> References: <20221109115047.2921851-1-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Introduce recomp_algorithm sysfs knob that controls secondary algorithm selection used for recompression. We will support up to 3 secondary compression algorithms which are sorted in order of their priority. To select an algorithm user has to provide its name and priority: echo "algo=3Dzstd priority=3D1" > /sys/block/zramX/recomp_algorithm echo "algo=3Ddeflate priority=3D2" > /sys/block/zramX/recomp_algorithm During recompression zram iterates through the list of registered secondary algorithms in order of their priorities. We also have a short version for cases when there is only one secondary compression algorithm: echo "algo=3Dzstd" > /sys/block/zramX/recomp_algorithm This will register zstd as the secondary algorithm with priority 1. Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- drivers/block/zram/zram_drv.c | 124 ++++++++++++++++++++++++++++------ 1 file changed, 105 insertions(+), 19 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 5371ed63c785..56026a6deb70 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1000,31 +1000,28 @@ static ssize_t max_comp_streams_store(struct device= *dev, return len; } =20 -static ssize_t comp_algorithm_show(struct device *dev, - struct device_attribute *attr, char *buf) +static void comp_algorithm_set(struct zram *zram, u32 prio, const char *al= g) { - size_t sz; - struct zram *zram =3D dev_to_zram(dev); + /* Do not free statically defined compression algorithms */ + if (zram->comp_algs[prio] !=3D default_compressor) + kfree(zram->comp_algs[prio]); + + zram->comp_algs[prio] =3D alg; +} + +static ssize_t __comp_algorithm_show(struct zram *zram, u32 prio, char *bu= f) +{ + ssize_t sz; =20 down_read(&zram->init_lock); - sz =3D zcomp_available_show(zram->comp_algs[ZRAM_PRIMARY_COMP], buf); + sz =3D zcomp_available_show(zram->comp_algs[prio], buf); up_read(&zram->init_lock); =20 return sz; } =20 -static void comp_algorithm_set(struct zram *zram, u32 prio, const char *al= g) +static int __comp_algorithm_store(struct zram *zram, u32 prio, const char = *buf) { - /* Do not kfree() algs that we didn't allocate, IOW the default ones */ - if (zram->comp_algs[prio] !=3D default_compressor) - kfree(zram->comp_algs[prio]); - zram->comp_algs[prio] =3D alg; -} - -static ssize_t comp_algorithm_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) -{ - struct zram *zram =3D dev_to_zram(dev); char *compressor; size_t sz; =20 @@ -1053,11 +1050,94 @@ static ssize_t comp_algorithm_store(struct device *= dev, return -EBUSY; } =20 - comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, compressor); + comp_algorithm_set(zram, prio, compressor); up_write(&zram->init_lock); - return len; + return 0; +} + +static ssize_t comp_algorithm_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct zram *zram =3D dev_to_zram(dev); + + return __comp_algorithm_show(zram, ZRAM_PRIMARY_COMP, buf); +} + +static ssize_t comp_algorithm_store(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t len) +{ + struct zram *zram =3D dev_to_zram(dev); + int ret; + + ret =3D __comp_algorithm_store(zram, ZRAM_PRIMARY_COMP, buf); + return ret ? ret : len; } =20 +#ifdef CONFIG_ZRAM_MULTI_COMP +static ssize_t recomp_algorithm_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct zram *zram =3D dev_to_zram(dev); + ssize_t sz =3D 0; + u32 prio; + + for (prio =3D ZRAM_SECONDARY_COMP; prio < ZRAM_MAX_COMPS; prio++) { + if (!zram->comp_algs[prio]) + continue; + + sz +=3D scnprintf(buf + sz, PAGE_SIZE - sz - 2, "#%d: ", prio); + sz +=3D __comp_algorithm_show(zram, prio, buf + sz); + } + + return sz; +} + +static ssize_t recomp_algorithm_store(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t len) +{ + struct zram *zram =3D dev_to_zram(dev); + int prio =3D ZRAM_SECONDARY_COMP; + char *args, *param, *val; + char *alg =3D NULL; + int ret; + + args =3D skip_spaces(buf); + while (*args) { + args =3D next_arg(args, ¶m, &val); + + if (!*val) + return -EINVAL; + + if (!strcmp(param, "algo")) { + alg =3D val; + continue; + } + + if (!strcmp(param, "priority")) { + ret =3D kstrtoint(val, 10, &prio); + if (ret) + return ret; + continue; + } + } + + if (!alg) + return -EINVAL; + + if (prio < ZRAM_SECONDARY_COMP || prio >=3D ZRAM_MAX_COMPS) + return -EINVAL; + + ret =3D __comp_algorithm_store(zram, prio, alg); + return ret ? ret : len; +} +#endif + static ssize_t compact_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { @@ -1898,6 +1978,9 @@ static DEVICE_ATTR_WO(writeback); static DEVICE_ATTR_RW(writeback_limit); static DEVICE_ATTR_RW(writeback_limit_enable); #endif +#ifdef CONFIG_ZRAM_MULTI_COMP +static DEVICE_ATTR_RW(recomp_algorithm); +#endif =20 static struct attribute *zram_disk_attrs[] =3D { &dev_attr_disksize.attr, @@ -1921,6 +2004,9 @@ static struct attribute *zram_disk_attrs[] =3D { &dev_attr_bd_stat.attr, #endif &dev_attr_debug_stat.attr, +#ifdef CONFIG_ZRAM_MULTI_COMP + &dev_attr_recomp_algorithm.attr, +#endif NULL, }; =20 @@ -2000,7 +2086,7 @@ static int zram_add(void) if (ret) goto out_cleanup_disk; =20 - zram->comp_algs[ZRAM_PRIMARY_COMP] =3D default_compressor; + comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, default_compressor); =20 zram_debugfs_register(zram); pr_info("Added device: %s\n", zram->disk->disk_name); --=20 2.38.1.431.g37b22c650d-goog From nobody Mon Sep 15 20:41:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6E34C4332F for ; Wed, 9 Nov 2022 11:51:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230501AbiKILvO (ORCPT ); Wed, 9 Nov 2022 06:51:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34386 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230389AbiKILvG (ORCPT ); Wed, 9 Nov 2022 06:51:06 -0500 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EECE32CCA7 for ; Wed, 9 Nov 2022 03:51:02 -0800 (PST) Received: by mail-pl1-x62f.google.com with SMTP id c2so16841053plz.11 for ; Wed, 09 Nov 2022 03:51:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=NwLhHMvq7VueCMpUkTq+C+HTS32+Lk3Kl1y4kkNY1lI=; b=XU5vLFwkohaoQzaV3wsD4syG9ewC5z9qtbUASnBpI7yZfx6A/26UPA/KGss1F89lzr bLhHgQibUdXpBvhVKkTalBkDQSjdosyCaORUHtLQtl3nxDZaeFifxXfpsE09Dx1L42Ag Lh43EhiVNoB8JL3gbSz6XvnAW519pupdtZBZ0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=NwLhHMvq7VueCMpUkTq+C+HTS32+Lk3Kl1y4kkNY1lI=; b=1Zh0k5jJd0nvbRNteAzackm72/J2rpIj9YjCA6GtJ6ERbd3g/JFCZSetK/SlDvzlwg CmblpujQpzth0Ry3h+jh4ZH9so+lrKQzrl/YeBjXa29hDVuIUEb6KGFFQvkyPhgOxnFU amKtOLYZXkRArzRuHMFZiCsUfjdO2sx+nitd6zT7oBHjSd27cxQso5IogIyX5GjHfS1W m2LJWoT4vX/UCogS5QPPK1yffn93NHtNrlMdF+hEfg8YDONxyfkdim6KLUjTVMqZ2GQc vy/BjZ8tJU5YSW0LGcbHkxobT3q7Woe2CfpkF2VV4VJ9gj+6PRgulbsjC0lVdVWp0TUU oRvQ== X-Gm-Message-State: ACrzQf3hngyvu5qbculHHRsys01HK9uY8ggqFMCDRY9nUuJkOVOP4Ocj v1aCiq2RZeETNr2KNFgdaGRNzg== X-Google-Smtp-Source: AMsMyM6YjoApz2cmt93xkc5aPeuhMLaP2uc6ExE39WsDWmfAadxJs9lufYlSSW28eW1IwTrpZrxuvA== X-Received: by 2002:a17:90b:3b8d:b0:214:1066:67c7 with SMTP id pc13-20020a17090b3b8d00b00214106667c7mr45511923pjb.209.1667994662480; Wed, 09 Nov 2022 03:51:02 -0800 (PST) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:61f1:44d3:3f47:2cdb]) by smtp.gmail.com with ESMTPSA id f5-20020a655505000000b00434760ee36asm7292311pgr.16.2022.11.09.03.51.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Nov 2022 03:51:02 -0800 (PST) From: Sergey Senozhatsky To: Minchan Kim , Andrew Morton Cc: Nitin Gupta , Suleiman Souhlal , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sergey Senozhatsky Subject: [PATCHv5 03/13] zram: Factor out WB and non-WB zram read functions Date: Wed, 9 Nov 2022 20:50:37 +0900 Message-Id: <20221109115047.2921851-4-senozhatsky@chromium.org> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <20221109115047.2921851-1-senozhatsky@chromium.org> References: <20221109115047.2921851-1-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" We will use non-WB variant in ZRAM page recompression path. Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- drivers/block/zram/zram_drv.c | 72 ++++++++++++++++++++++++----------- 1 file changed, 49 insertions(+), 23 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 56026a6deb70..a6a5fd2474d7 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1339,8 +1339,29 @@ static void zram_free_page(struct zram *zram, size_t= index) ~(1UL << ZRAM_LOCK | 1UL << ZRAM_UNDER_WB)); } =20 -static int __zram_bvec_read(struct zram *zram, struct page *page, u32 inde= x, - struct bio *bio, bool partial_io) +/* + * Reads a page from the writeback devices. Corresponding ZRAM slot + * should be unlocked. + */ +static int zram_bvec_read_from_bdev(struct zram *zram, struct page *page, + u32 index, struct bio *bio, bool partial_io) +{ + struct bio_vec bvec =3D { + .bv_page =3D page, + .bv_len =3D PAGE_SIZE, + .bv_offset =3D 0, + }; + + return read_from_bdev(zram, &bvec, zram_get_element(zram, index), bio, + partial_io); +} + +/* + * Reads (decompresses if needed) a page from zspool (zsmalloc). + * Corresponding ZRAM slot should be locked. + */ +static int zram_read_from_zspool(struct zram *zram, struct page *page, + u32 index) { struct zcomp_strm *zstrm; unsigned long handle; @@ -1348,23 +1369,6 @@ static int __zram_bvec_read(struct zram *zram, struc= t page *page, u32 index, void *src, *dst; int ret; =20 - zram_slot_lock(zram, index); - if (zram_test_flag(zram, index, ZRAM_WB)) { - struct bio_vec bvec; - - zram_slot_unlock(zram, index); - /* A null bio means rw_page was used, we must fallback to bio */ - if (!bio) - return -EOPNOTSUPP; - - bvec.bv_page =3D page; - bvec.bv_len =3D PAGE_SIZE; - bvec.bv_offset =3D 0; - return read_from_bdev(zram, &bvec, - zram_get_element(zram, index), - bio, partial_io); - } - handle =3D zram_get_handle(zram, index); if (!handle || zram_test_flag(zram, index, ZRAM_SAME)) { unsigned long value; @@ -1374,7 +1378,6 @@ static int __zram_bvec_read(struct zram *zram, struct= page *page, u32 index, mem =3D kmap_atomic(page); zram_fill_page(mem, PAGE_SIZE, value); kunmap_atomic(mem); - zram_slot_unlock(zram, index); return 0; } =20 @@ -1396,17 +1399,40 @@ static int __zram_bvec_read(struct zram *zram, stru= ct page *page, u32 index, zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]); } zs_unmap_object(zram->mem_pool, handle); - zram_slot_unlock(zram, index); + return ret; +} + +static int __zram_bvec_read(struct zram *zram, struct page *page, u32 inde= x, + struct bio *bio, bool partial_io) +{ + int ret; + + zram_slot_lock(zram, index); + if (!zram_test_flag(zram, index, ZRAM_WB)) { + /* Slot should be locked through out the function call */ + ret =3D zram_read_from_zspool(zram, page, index); + zram_slot_unlock(zram, index); + } else { + /* Slot should be unlocked before the function call */ + zram_slot_unlock(zram, index); + + /* A null bio means rw_page was used, we must fallback to bio */ + if (!bio) + return -EOPNOTSUPP; + + ret =3D zram_bvec_read_from_bdev(zram, page, index, bio, + partial_io); + } =20 /* Should NEVER happen. Return bio error if it does. */ - if (WARN_ON(ret)) + if (WARN_ON(ret < 0)) pr_err("Decompression failed! err=3D%d, page=3D%u\n", ret, index); =20 return ret; } =20 static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec, - u32 index, int offset, struct bio *bio) + u32 index, int offset, struct bio *bio) { int ret; struct page *page; --=20 2.38.1.431.g37b22c650d-goog From nobody Mon Sep 15 20:41:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 237A3C4332F for ; Wed, 9 Nov 2022 11:51:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230408AbiKILvV (ORCPT ); Wed, 9 Nov 2022 06:51:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230475AbiKILvH (ORCPT ); Wed, 9 Nov 2022 06:51:07 -0500 Received: from mail-pg1-x536.google.com (mail-pg1-x536.google.com [IPv6:2607:f8b0:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 97DF32EF22 for ; Wed, 9 Nov 2022 03:51:05 -0800 (PST) Received: by mail-pg1-x536.google.com with SMTP id 6so7882208pgm.6 for ; Wed, 09 Nov 2022 03:51:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=n33F25aQVl5gMALLYTt7F+KllpnjMjEm9LlYHN1WT00=; b=Rh2BlWtYS21q0RL18T9fNl9H/b1v7TFvFlPRO/DpVHp+5NppILseTVaEWsK9ZpAFR2 gVvXlR10W5bORh+1bAKmeuf2JHm7eYWkze5Ysg4+LSwQNlYj+PoCgz4bUzxa2VNBInas fd0c3WKvxwSED3juQz7UrslELXMc/sBuqQy7w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=n33F25aQVl5gMALLYTt7F+KllpnjMjEm9LlYHN1WT00=; b=ylyjj/BqHO0Gd9dkd6K2cvIQtnyvyUFk8DvQ76yAMVI7qLhBqznUeo8ev0eZFR7jjd EontwDhVpCuhjqOhqQXbKxIRtoPej5ddDJ2GcnZQ+DL4kXbZKkAbWXFz8Rh+6P9FD+lY t0HjzeWYdExw1ELzq62Aqhd+5OzFStZVprOidXC1+q6xo6qPhHC9d2882KqJyfA0N0vT rz3lfbmdw5g1ZzVOJCDCodZDTHqRuQWv9Mw765mEAh+q91scL09avqXJRCjqD0k+pTBn P2/hjaJpRwMI5Mt/9VCEcdronITSNsnldpQPlJjMRbBctNkw6lXml2JxeW5hzdG9YGnM lXfg== X-Gm-Message-State: ACrzQf1nTh5etVX09XLzypUpK9GH7foGzNHW1rDGS19gF1ZJ2s1nRlYg XcyRCI63+ix27OsR++q2fq28bw== X-Google-Smtp-Source: AMsMyM7p8pimAY7i/uNHTUklIfUHS9rEp4bNx9mbfWjFZIjoKxPIfq1X7n0uEgwxpOt6ckLrwn/gOQ== X-Received: by 2002:a05:6a00:10cf:b0:528:48c3:79e0 with SMTP id d15-20020a056a0010cf00b0052848c379e0mr60134369pfu.18.1667994665061; Wed, 09 Nov 2022 03:51:05 -0800 (PST) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:61f1:44d3:3f47:2cdb]) by smtp.gmail.com with ESMTPSA id f5-20020a655505000000b00434760ee36asm7292311pgr.16.2022.11.09.03.51.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Nov 2022 03:51:04 -0800 (PST) From: Sergey Senozhatsky To: Minchan Kim , Andrew Morton Cc: Nitin Gupta , Suleiman Souhlal , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sergey Senozhatsky Subject: [PATCHv5 04/13] zram: Introduce recompress sysfs knob Date: Wed, 9 Nov 2022 20:50:38 +0900 Message-Id: <20221109115047.2921851-5-senozhatsky@chromium.org> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <20221109115047.2921851-1-senozhatsky@chromium.org> References: <20221109115047.2921851-1-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Allow zram to recompress (using secondary compression streams) pages. Re-compression algorithms (we support up to 3 at this stage) are selected via recomp_algorithm: echo "algo=3Dzstd priority=3D1" > /sys/block/zramX/recomp_algorithm Please read documentation for more details. We support several recompression modes: 1) IDLE pages recompression is activated by `idle` mode echo "type=3Didle" > /sys/block/zram0/recompress 2) Since there may be many idle pages user-space may pass a size threshold value (in bytes) and we will recompress pages only of equal or greater size: echo "threshold=3D888" > /sys/block/zram0/recompress 3) HUGE pages recompression is activated by `huge` mode echo "type=3Dhuge" > /sys/block/zram0/recompress 4) HUGE_IDLE pages recompression is activated by `huge_idle` mode echo "type=3Dhuge_idle" > /sys/block/zram0/recompress Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- drivers/block/zram/Kconfig | 9 ++ drivers/block/zram/zram_drv.c | 264 +++++++++++++++++++++++++++++++++- drivers/block/zram/zram_drv.h | 7 + 3 files changed, 277 insertions(+), 3 deletions(-) diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig index d4100b0c083e..0386b7da02aa 100644 --- a/drivers/block/zram/Kconfig +++ b/drivers/block/zram/Kconfig @@ -78,3 +78,12 @@ config ZRAM_MEMORY_TRACKING /sys/kernel/debug/zram/zramX/block_state. =20 See Documentation/admin-guide/blockdev/zram.rst for more information. + +config ZRAM_MULTI_COMP + bool "Enable multiple compression streams" + depends on ZRAM + help + This will enable multi-compression streams, so that ZRAM can + re-compress pages using a potentially slower but more effective + compression algorithm. Note, that IDLE page recompression + requires ZRAM_MEMORY_TRACKING. diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index a6a5fd2474d7..749e4266dd72 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -155,6 +155,25 @@ static inline bool is_partial_io(struct bio_vec *bvec) } #endif =20 +static inline void zram_set_priority(struct zram *zram, u32 index, u32 pri= o) +{ + prio &=3D ZRAM_COMP_PRIORITY_MASK; + /* + * Clear previous priority value first, in case if we recompress + * further an already recompressed page + */ + zram->table[index].flags &=3D ~(ZRAM_COMP_PRIORITY_MASK << + ZRAM_COMP_PRIORITY_BIT1); + zram->table[index].flags |=3D (prio << ZRAM_COMP_PRIORITY_BIT1); +} + +static inline u32 zram_get_priority(struct zram *zram, u32 index) +{ + u32 prio =3D zram->table[index].flags >> ZRAM_COMP_PRIORITY_BIT1; + + return prio & ZRAM_COMP_PRIORITY_MASK; +} + /* * Check if request is within bounds and aligned on zram logical blocks. */ @@ -1307,6 +1326,11 @@ static void zram_free_page(struct zram *zram, size_t= index) atomic64_dec(&zram->stats.huge_pages); } =20 + if (zram_test_flag(zram, index, ZRAM_INCOMPRESSIBLE)) + zram_clear_flag(zram, index, ZRAM_INCOMPRESSIBLE); + + zram_set_priority(zram, index, 0); + if (zram_test_flag(zram, index, ZRAM_WB)) { zram_clear_flag(zram, index, ZRAM_WB); free_block_bdev(zram, zram_get_element(zram, index)); @@ -1367,6 +1391,7 @@ static int zram_read_from_zspool(struct zram *zram, s= truct page *page, unsigned long handle; unsigned int size; void *src, *dst; + u32 prio; int ret; =20 handle =3D zram_get_handle(zram, index); @@ -1383,8 +1408,10 @@ static int zram_read_from_zspool(struct zram *zram, = struct page *page, =20 size =3D zram_get_obj_size(zram, index); =20 - if (size !=3D PAGE_SIZE) - zstrm =3D zcomp_stream_get(zram->comps[ZRAM_PRIMARY_COMP]); + if (size !=3D PAGE_SIZE) { + prio =3D zram_get_priority(zram, index); + zstrm =3D zcomp_stream_get(zram->comps[prio]); + } =20 src =3D zs_map_object(zram->mem_pool, handle, ZS_MM_RO); if (size =3D=3D PAGE_SIZE) { @@ -1396,7 +1423,7 @@ static int zram_read_from_zspool(struct zram *zram, s= truct page *page, dst =3D kmap_atomic(page); ret =3D zcomp_decompress(zstrm, src, size, dst); kunmap_atomic(dst); - zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]); + zcomp_stream_put(zram->comps[prio]); } zs_unmap_object(zram->mem_pool, handle); return ret; @@ -1627,6 +1654,235 @@ static int zram_bvec_write(struct zram *zram, struc= t bio_vec *bvec, return ret; } =20 +#ifdef CONFIG_ZRAM_MULTI_COMP +/* + * This function will decompress (unless it's ZRAM_HUGE) the page and then + * attempt to compress it using provided compression algorithm priority + * (which is potentially more effective). + * + * Corresponding ZRAM slot should be locked. + */ +static int zram_recompress(struct zram *zram, u32 index, struct page *page, + u32 threshold, u32 prio, u32 prio_max) +{ + struct zcomp_strm *zstrm =3D NULL; + unsigned long handle_old; + unsigned long handle_new; + unsigned int comp_len_old; + unsigned int comp_len_new; + void *src, *dst; + int ret; + + handle_old =3D zram_get_handle(zram, index); + if (!handle_old) + return -EINVAL; + + comp_len_old =3D zram_get_obj_size(zram, index); + /* + * Do not recompress objects that are already "small enough". + */ + if (comp_len_old < threshold) + return 0; + + ret =3D zram_read_from_zspool(zram, page, index); + if (ret) + return ret; + + /* + * Iterate the secondary comp algorithms list (in order of priority) + * and try to recompress the page. + */ + for (; prio < prio_max; prio++) { + if (!zram->comps[prio]) + continue; + + /* + * Skip if the object is already re-compressed with a higher + * priority algorithm (or same algorithm). + */ + if (prio <=3D zram_get_priority(zram, index)) + continue; + + zstrm =3D zcomp_stream_get(zram->comps[prio]); + src =3D kmap_atomic(page); + ret =3D zcomp_compress(zstrm, src, &comp_len_new); + kunmap_atomic(src); + + if (ret) { + zcomp_stream_put(zram->comps[prio]); + return ret; + } + + /* Continue until we make progress */ + if (comp_len_new >=3D huge_class_size || + comp_len_new >=3D comp_len_old || + (threshold && comp_len_new >=3D threshold)) { + zcomp_stream_put(zram->comps[prio]); + continue; + } + + /* Recompression was successful so break out */ + break; + } + + /* + * We did not try to recompress, e.g. when we have only one + * secondary algorithm and the page is already recompressed + * using that algorithm + */ + if (!zstrm) + return 0; + + /* + * All secondary algorithms failed to re-compress the page in a way + * that would save memory, mark the object as incompressible so that + * we will not try to compress it again. + */ + if (comp_len_new >=3D huge_class_size || comp_len_new >=3D comp_len_old) { + zram_set_flag(zram, index, ZRAM_INCOMPRESSIBLE); + return 0; + } + + /* Successful recompression but above threshold */ + if (threshold && comp_len_new >=3D threshold) + return 0; + + /* + * No direct reclaim (slow path) for handle allocation and no + * re-compression attempt (unlike in __zram_bvec_write()) since + * we already have stored that object in zsmalloc. If we cannot + * alloc memory for recompressed object then we bail out and + * simply keep the old (existing) object in zsmalloc. + */ + handle_new =3D zs_malloc(zram->mem_pool, comp_len_new, + __GFP_KSWAPD_RECLAIM | + __GFP_NOWARN | + __GFP_HIGHMEM | + __GFP_MOVABLE); + if (IS_ERR_VALUE(handle_new)) { + zcomp_stream_put(zram->comps[prio]); + return PTR_ERR((void *)handle_new); + } + + dst =3D zs_map_object(zram->mem_pool, handle_new, ZS_MM_WO); + memcpy(dst, zstrm->buffer, comp_len_new); + zcomp_stream_put(zram->comps[prio]); + + zs_unmap_object(zram->mem_pool, handle_new); + + zram_free_page(zram, index); + zram_set_handle(zram, index, handle_new); + zram_set_obj_size(zram, index, comp_len_new); + zram_set_priority(zram, index, prio); + + atomic64_add(comp_len_new, &zram->stats.compr_data_size); + atomic64_inc(&zram->stats.pages_stored); + + return 0; +} + +#define RECOMPRESS_IDLE (1 << 0) +#define RECOMPRESS_HUGE (1 << 1) + +static ssize_t recompress_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct zram *zram =3D dev_to_zram(dev); + u32 mode =3D 0, threshold =3D 0, prio =3D ZRAM_SECONDARY_COMP; + unsigned long nr_pages =3D zram->disksize >> PAGE_SHIFT; + char *args, *param, *val; + unsigned long index; + struct page *page; + ssize_t ret; + + args =3D skip_spaces(buf); + while (*args) { + args =3D next_arg(args, ¶m, &val); + + if (!*val) + return -EINVAL; + + if (!strcmp(param, "type")) { + if (!strcmp(val, "idle")) + mode =3D RECOMPRESS_IDLE; + if (!strcmp(val, "huge")) + mode =3D RECOMPRESS_HUGE; + if (!strcmp(val, "huge_idle")) + mode =3D RECOMPRESS_IDLE | RECOMPRESS_HUGE; + continue; + } + + if (!strcmp(param, "threshold")) { + /* + * We will re-compress only idle objects equal or + * greater in size than watermark. + */ + ret =3D kstrtouint(val, 10, &threshold); + if (ret) + return ret; + continue; + } + } + + if (threshold >=3D PAGE_SIZE) + return -EINVAL; + + down_read(&zram->init_lock); + if (!init_done(zram)) { + ret =3D -EINVAL; + goto release_init_lock; + } + + page =3D alloc_page(GFP_KERNEL); + if (!page) { + ret =3D -ENOMEM; + goto release_init_lock; + } + + ret =3D len; + for (index =3D 0; index < nr_pages; index++) { + int err; + + zram_slot_lock(zram, index); + + if (!zram_allocated(zram, index)) + goto next; + + if (mode & RECOMPRESS_IDLE && + !zram_test_flag(zram, index, ZRAM_IDLE)) + goto next; + + if (mode & RECOMPRESS_HUGE && + !zram_test_flag(zram, index, ZRAM_HUGE)) + goto next; + + if (zram_test_flag(zram, index, ZRAM_WB) || + zram_test_flag(zram, index, ZRAM_UNDER_WB) || + zram_test_flag(zram, index, ZRAM_SAME) || + zram_test_flag(zram, index, ZRAM_INCOMPRESSIBLE)) + goto next; + + err =3D zram_recompress(zram, index, page, threshold, + prio, ZRAM_MAX_COMPS); +next: + zram_slot_unlock(zram, index); + if (err) { + ret =3D err; + break; + } + + cond_resched(); + } + + __free_page(page); + +release_init_lock: + up_read(&zram->init_lock); + return ret; +} +#endif + /* * zram_bio_discard - handler on discard request * @index: physical block index in PAGE_SIZE units @@ -2006,6 +2262,7 @@ static DEVICE_ATTR_RW(writeback_limit_enable); #endif #ifdef CONFIG_ZRAM_MULTI_COMP static DEVICE_ATTR_RW(recomp_algorithm); +static DEVICE_ATTR_WO(recompress); #endif =20 static struct attribute *zram_disk_attrs[] =3D { @@ -2032,6 +2289,7 @@ static struct attribute *zram_disk_attrs[] =3D { &dev_attr_debug_stat.attr, #ifdef CONFIG_ZRAM_MULTI_COMP &dev_attr_recomp_algorithm.attr, + &dev_attr_recompress.attr, #endif NULL, }; diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index 7a643c8c38ec..b80faae76835 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -40,6 +40,9 @@ */ #define ZRAM_FLAG_SHIFT (PAGE_SHIFT + 1) =20 +/* Only 2 bits are allowed for comp priority index */ +#define ZRAM_COMP_PRIORITY_MASK 0x3 + /* Flags for zram pages (table[page_no].flags) */ enum zram_pageflags { /* zram slot is locked */ @@ -49,6 +52,10 @@ enum zram_pageflags { ZRAM_UNDER_WB, /* page is under writeback */ ZRAM_HUGE, /* Incompressible page */ ZRAM_IDLE, /* not accessed page since last idle marking */ + ZRAM_INCOMPRESSIBLE, /* none of the algorithms could compress it */ + + ZRAM_COMP_PRIORITY_BIT1, /* First bit of comp priority index */ + ZRAM_COMP_PRIORITY_BIT2, /* Second bit of comp priority index */ =20 __NR_ZRAM_PAGEFLAGS, }; 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charset="utf-8" Add a new flag to zram block state that shows if the page was recompressed (using alternative compression algorithm). Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- Documentation/admin-guide/blockdev/zram.rst | 9 ++++++--- drivers/block/zram/zram_drv.c | 5 +++-- 2 files changed, 9 insertions(+), 5 deletions(-) diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/ad= min-guide/blockdev/zram.rst index c73b16930449..177a142c3146 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -411,9 +411,10 @@ pages of the process with*pagemap. If you enable the feature, you could see block state via /sys/kernel/debug/zram/zram0/block_state". The output is as follows:: =20 - 300 75.033841 .wh. - 301 63.806904 s... - 302 63.806919 ..hi + 300 75.033841 .wh.. + 301 63.806904 s.... + 302 63.806919 ..hi. + 303 62.801919 ....r =20 First column zram's block index. @@ -430,6 +431,8 @@ Third column huge page i: idle page + r: + recompressed page (secondary compression algorithm) =20 First line of above example says 300th block is accessed at 75.033841sec and the block's state is huge so it is written back to the backing diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 749e4266dd72..560e2932021e 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -939,13 +939,14 @@ static ssize_t read_block_state(struct file *file, ch= ar __user *buf, =20 ts =3D ktime_to_timespec64(zram->table[index].ac_time); copied =3D snprintf(kbuf + written, count, - "%12zd %12lld.%06lu %c%c%c%c\n", + "%12zd %12lld.%06lu %c%c%c%c%c\n", index, (s64)ts.tv_sec, ts.tv_nsec / NSEC_PER_USEC, zram_test_flag(zram, index, ZRAM_SAME) ? 's' : '.', zram_test_flag(zram, index, ZRAM_WB) ? 'w' : '.', zram_test_flag(zram, index, ZRAM_HUGE) ? 'h' : '.', - zram_test_flag(zram, index, ZRAM_IDLE) ? 'i' : '.'); + zram_test_flag(zram, index, ZRAM_IDLE) ? 'i' : '.', + zram_get_priority(zram, index) ? 'r' : '.'); =20 if (count <=3D copied) { zram_slot_unlock(zram, index); --=20 2.38.1.431.g37b22c650d-goog From nobody Mon Sep 15 20:41:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AFCE0C4332F for ; Wed, 9 Nov 2022 11:51:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231280AbiKILvf (ORCPT ); Wed, 9 Nov 2022 06:51:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230477AbiKILvR (ORCPT ); Wed, 9 Nov 2022 06:51:17 -0500 Received: from mail-pf1-x42b.google.com (mail-pf1-x42b.google.com [IPv6:2607:f8b0:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A9D073120B for ; Wed, 9 Nov 2022 03:51:10 -0800 (PST) Received: by mail-pf1-x42b.google.com with SMTP id g62so16446193pfb.10 for ; Wed, 09 Nov 2022 03:51:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Yx/j6NFsqMiBfWUe9MAE1kY4nyT9uBWrAowemE/mjWM=; b=PRtW06hqJjnQd/kkrH5EdBvx+MeI+nT/zaRSXLQ34yFFZSjedoVDMt0ITBHY9lEJZL zv+rYGTJbr/jbll1pBLICDHoduO6RLnRUwbZgzJ4UPSTNt9sozFtY/xW98UZAXvjbMTU R6GqKRwlu/wYEXfZCbhs9SLFZ3xhLlXZm6oO4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Yx/j6NFsqMiBfWUe9MAE1kY4nyT9uBWrAowemE/mjWM=; b=UF20SpYEhxMp7TEtADMjmrMrgPjyGXR1iqxPosJzZd2hWdolmiDp59JH0BHhlf5+FL q9dlYy4fP8/yNyMVguhNvN+O7beXyJIDahA16l6cl391WlTMN8UCefS/FRc4Oc+nmjjA 8OnqR1LzpDoPmL3vk09c0p/icOUK4SW8Gc13RDT1K0IzbJNy/8g0ITOvJ/rX85AAyZ74 b1CP/5SabSjSq40u1jqYTSnG8whfG3IpKIJwjAosCYRvZh16FqmRTXNmy+ee0GNm4BFV 2J2fPDhLemiD8ed1LRpX0dBtOiXwl8nFKBhB8BRI9XSzud/EgFD3MHC5p7nahRJ0wO3M 2UxA== X-Gm-Message-State: ACrzQf0igTZYUfnhlDVsrxDvT9pkvI/HDadfAdbRKlYKGkrTBxBwg1br hl8CCvC9wpFPhQEPlMslCGi2x7FxON+OGg== X-Google-Smtp-Source: AMsMyM4QC8IeHoMzd41nyT4jdl6i2t22PgNfGcqVzLXa+joYnG9IWHujjdaIiEn2O1jPLNxZ/+ziUQ== X-Received: by 2002:a63:f755:0:b0:44b:e438:ef2f with SMTP id f21-20020a63f755000000b0044be438ef2fmr52609729pgk.314.1667994670169; Wed, 09 Nov 2022 03:51:10 -0800 (PST) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:61f1:44d3:3f47:2cdb]) by smtp.gmail.com with ESMTPSA id f5-20020a655505000000b00434760ee36asm7292311pgr.16.2022.11.09.03.51.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Nov 2022 03:51:09 -0800 (PST) From: Sergey Senozhatsky To: Minchan Kim , Andrew Morton Cc: Nitin Gupta , Suleiman Souhlal , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sergey Senozhatsky Subject: [PATCHv5 06/13] zram: Clarify writeback_store() comment Date: Wed, 9 Nov 2022 20:50:40 +0900 Message-Id: <20221109115047.2921851-7-senozhatsky@chromium.org> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <20221109115047.2921851-1-senozhatsky@chromium.org> References: <20221109115047.2921851-1-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Re-phrase writeback BIO error comment. Reported-by: Andrew Morton Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- drivers/block/zram/zram_drv.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 560e2932021e..a5d2ce0bcd5d 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -772,8 +772,12 @@ static ssize_t writeback_store(struct device *dev, zram_clear_flag(zram, index, ZRAM_IDLE); zram_slot_unlock(zram, index); /* - * Return last IO error unless every IO were - * not suceeded. + * BIO errors are not fatal, we continue and simply + * attempt to writeback the remaining objects (pages). + * At the same time we need to signal user-space that + * some writes (at least one, but also could be all of + * them) were not successful and we do so by returning + * the most recent BIO error. */ ret =3D err; continue; --=20 2.38.1.431.g37b22c650d-goog From nobody Mon Sep 15 20:41:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4FA25C433FE for ; Wed, 9 Nov 2022 11:51:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229985AbiKILvi (ORCPT ); Wed, 9 Nov 2022 06:51:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230492AbiKILvV (ORCPT ); Wed, 9 Nov 2022 06:51:21 -0500 Received: from mail-pg1-x532.google.com (mail-pg1-x532.google.com [IPv6:2607:f8b0:4864:20::532]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65181317C2 for ; Wed, 9 Nov 2022 03:51:13 -0800 (PST) Received: by mail-pg1-x532.google.com with SMTP id f63so16030088pgc.2 for ; Wed, 09 Nov 2022 03:51:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=LtxYsj6E0bxgea4oeDPQD6uPBfUoT8WqWkKOxHgnlE8=; b=BhhFMs1ML3PGfZKVrN186Q97ul+1G9ZHCoV+RVoLQr8lz4T5uyEB8FVWXqOd2MPEJV WXRNdPNw5zFbek9OBqFeG95mqUcpvBVSA9OgxkLNbzSfXs/gtXDE0iZciXnFTnO7xbEx VVL2cpPMLshWAYupNPDK+0SFTzwaSKVuxvrqg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=LtxYsj6E0bxgea4oeDPQD6uPBfUoT8WqWkKOxHgnlE8=; b=GvhpGOkqJVb5zpkVOWB+sa/330gwKTAJPQAcKLaUZtqsRZBlJlK3P7uB1L/xWy61pR GB3v6UfuUC5e2R2i2YVYEg5dSrMG416aqG98xscP3VXqxCjb37017buvomnTFwyF3m6i /CdjNDTehCyVkUKUPkOuRtYJMELE1sOSlJ7FLxinY6I6h6x54I05fzKzrwd9Hd+jM/by nsCqt16PlPN65emMfEPTsG6ervuILv8xlBj3ajRZPB9T6ItRLEyW2Xuz37eg/oVhvTTA zKGt5daWjsy2W7D9CPZtwAGx5XQjFQVTmlPwKYF3fjxr5GVfdDnGob5wtzNMZqzZAJzJ T6Ag== X-Gm-Message-State: ANoB5pnfjd9atNGcfnf4cqMNh/OlG52wboi3/ezlK3qlemGgGnp7irPI saUeum7FiYhNznQdATiyrlUtrg== X-Google-Smtp-Source: AA0mqf5O4dQwnhqX2UIonKGx0YaOrk9LZS0ppNcJn3lPaVyD2Siq7naWMzUGxAKXAAnyXSHio9Vedw== X-Received: by 2002:a65:6846:0:b0:470:8e8f:fe89 with SMTP id q6-20020a656846000000b004708e8ffe89mr5699996pgt.172.1667994672770; Wed, 09 Nov 2022 03:51:12 -0800 (PST) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:61f1:44d3:3f47:2cdb]) by smtp.gmail.com with ESMTPSA id f5-20020a655505000000b00434760ee36asm7292311pgr.16.2022.11.09.03.51.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Nov 2022 03:51:12 -0800 (PST) From: Sergey Senozhatsky To: Minchan Kim , Andrew Morton Cc: Nitin Gupta , Suleiman Souhlal , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sergey Senozhatsky Subject: [PATCHv5 07/13] zram: Use IS_ERR_VALUE() to check for zs_malloc() errors Date: Wed, 9 Nov 2022 20:50:41 +0900 Message-Id: <20221109115047.2921851-8-senozhatsky@chromium.org> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <20221109115047.2921851-1-senozhatsky@chromium.org> References: <20221109115047.2921851-1-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Avoid type casts that are needed for IS_ERR() and use IS_ERR_VALUE() instead. Suggested-by: Andrew Morton Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- drivers/block/zram/zram_drv.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index a5d2ce0bcd5d..9561569273fe 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1545,19 +1545,19 @@ static int __zram_bvec_write(struct zram *zram, str= uct bio_vec *bvec, * if we have a 'non-null' handle here then we are coming * from the slow path and handle has already been allocated. */ - if (IS_ERR((void *)handle)) + if (IS_ERR_VALUE(handle)) handle =3D zs_malloc(zram->mem_pool, comp_len, __GFP_KSWAPD_RECLAIM | __GFP_NOWARN | __GFP_HIGHMEM | __GFP_MOVABLE); - if (IS_ERR((void *)handle)) { + if (IS_ERR_VALUE(handle)) { zcomp_stream_put(zram->comps[ZRAM_PRIMARY_COMP]); atomic64_inc(&zram->stats.writestall); handle =3D zs_malloc(zram->mem_pool, comp_len, GFP_NOIO | __GFP_HIGHMEM | __GFP_MOVABLE); - if (IS_ERR((void *)handle)) + if (IS_ERR_VALUE(handle)) return PTR_ERR((void *)handle); =20 if (comp_len !=3D PAGE_SIZE) --=20 2.38.1.431.g37b22c650d-goog From nobody Mon Sep 15 20:41:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96372C433FE for ; Wed, 9 Nov 2022 11:51:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230411AbiKILvo (ORCPT ); Wed, 9 Nov 2022 06:51:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231166AbiKILvV (ORCPT ); Wed, 9 Nov 2022 06:51:21 -0500 Received: from mail-pg1-x536.google.com (mail-pg1-x536.google.com [IPv6:2607:f8b0:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D97772EF28 for ; Wed, 9 Nov 2022 03:51:15 -0800 (PST) Received: by mail-pg1-x536.google.com with SMTP id 6so7882595pgm.6 for ; Wed, 09 Nov 2022 03:51:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=ISzeUQbltZw2zOA4vUeGiMYh+5K7aaZl+AlK2yoDkbI=; b=abhQ1Lg35Ucp+NagZfYKvx4GbY0NqG+/hyXy+da3FyfoeakVv8aDDXACjC5rRaYMlE E3LixsEmNHw/j0vp8f/7HSXIgTj/qjh5U/zqtfM2h03rzuq8Scn+ixTQLqjY4CV5PBYE 62QyHJ431/vUwvGW0FiMJTSIr0gK1BLKAlU3Q= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ISzeUQbltZw2zOA4vUeGiMYh+5K7aaZl+AlK2yoDkbI=; b=4RM6dur7XV2gx+xI5ZlcAb1t5uPGUgBw5pq3TEteXljfFPeYIXjzm2hYOJqIJCpG+b CqGr0zEUpo+5LHRS1U3ihdCmfgs3zXG9stPUS04YvfgZ2bZdGF5XyBnJqFs4OueOwMIz lkbMNVcT3wp6QlDHv5JjNInwDBlAFndieZdbVIehnKoe64NUBcnuvRYPuSiNeahtjnFd W3kp4RM8leAsLbQ4BHmYIQ9UJiA7p6wbsyBBFV9ISpbfkFqW2z5nI4ErziGgkeSGV/iY Yhimjg6k/Gcoa9uvIRaGDvgLwBsAkRLPSwWb+eBOIkI79TFul35/2jePK+jpcPVWL+Dy NpdA== X-Gm-Message-State: ACrzQf2MzX+RZbs+sCIGBIaK5/mA29ziqnMppFTARUlQFH5s0QdG3qVX DbrsEzc6aqqDqgsSAlrh67XBoQ== X-Google-Smtp-Source: AMsMyM5bs/os1qCUXnfE9uDJ3/tdq0rmqwrB+hDi9koev9Tj6IMDU384APFO34LPFle2GUW6mVXbfw== X-Received: by 2002:a63:f047:0:b0:46e:b1d4:2a68 with SMTP id s7-20020a63f047000000b0046eb1d42a68mr51073818pgj.496.1667994675340; Wed, 09 Nov 2022 03:51:15 -0800 (PST) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:61f1:44d3:3f47:2cdb]) by smtp.gmail.com with ESMTPSA id f5-20020a655505000000b00434760ee36asm7292311pgr.16.2022.11.09.03.51.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Nov 2022 03:51:15 -0800 (PST) From: Sergey Senozhatsky To: Minchan Kim , Andrew Morton Cc: Nitin Gupta , Suleiman Souhlal , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sergey Senozhatsky , Alexey Romanov Subject: [PATCHv5 08/13] zram: add size class equals check into recompression Date: Wed, 9 Nov 2022 20:50:42 +0900 Message-Id: <20221109115047.2921851-9-senozhatsky@chromium.org> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <20221109115047.2921851-1-senozhatsky@chromium.org> References: <20221109115047.2921851-1-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Alexey Romanov It makes no sense for us to recompress the object if it will be in the same size class. We anyway don't get any memory gain. But, at the same time, we get a CPU time overhead when inserting this object into zspage and decompressing it afterwards. [senozhatsky: rebased and fixed conflicts] Signed-off-by: Alexey Romanov Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- drivers/block/zram/zram_drv.c | 11 ++++++++++- include/linux/zsmalloc.h | 2 ++ mm/zsmalloc.c | 21 +++++++++++++++++++++ 3 files changed, 33 insertions(+), 1 deletion(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 9561569273fe..383d967ef4c7 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1675,6 +1675,8 @@ static int zram_recompress(struct zram *zram, u32 ind= ex, struct page *page, unsigned long handle_new; unsigned int comp_len_old; unsigned int comp_len_new; + unsigned int class_index_old; + unsigned int class_index_new; void *src, *dst; int ret; =20 @@ -1693,6 +1695,7 @@ static int zram_recompress(struct zram *zram, u32 ind= ex, struct page *page, if (ret) return ret; =20 + class_index_old =3D zs_lookup_class_index(zram->mem_pool, comp_len_old); /* * Iterate the secondary comp algorithms list (in order of priority) * and try to recompress the page. @@ -1718,9 +1721,13 @@ static int zram_recompress(struct zram *zram, u32 in= dex, struct page *page, return ret; } =20 + class_index_new =3D zs_lookup_class_index(zram->mem_pool, + comp_len_new); + /* Continue until we make progress */ if (comp_len_new >=3D huge_class_size || comp_len_new >=3D comp_len_old || + class_index_new >=3D class_index_old || (threshold && comp_len_new >=3D threshold)) { zcomp_stream_put(zram->comps[prio]); continue; @@ -1743,7 +1750,9 @@ static int zram_recompress(struct zram *zram, u32 ind= ex, struct page *page, * that would save memory, mark the object as incompressible so that * we will not try to compress it again. */ - if (comp_len_new >=3D huge_class_size || comp_len_new >=3D comp_len_old) { + if (comp_len_new >=3D huge_class_size || + comp_len_new >=3D comp_len_old || + class_index_new >=3D class_index_old) { zram_set_flag(zram, index, ZRAM_INCOMPRESSIBLE); return 0; } diff --git a/include/linux/zsmalloc.h b/include/linux/zsmalloc.h index 2a430e713ce5..a48cd0ffe57d 100644 --- a/include/linux/zsmalloc.h +++ b/include/linux/zsmalloc.h @@ -55,5 +55,7 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long = handle); unsigned long zs_get_total_pages(struct zs_pool *pool); unsigned long zs_compact(struct zs_pool *pool); =20 +unsigned int zs_lookup_class_index(struct zs_pool *pool, unsigned int size= ); + void zs_pool_stats(struct zs_pool *pool, struct zs_pool_stats *stats); #endif diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index d03941cace2c..065744b7e9d8 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -1205,6 +1205,27 @@ static bool zspage_full(struct size_class *class, st= ruct zspage *zspage) return get_zspage_inuse(zspage) =3D=3D class->objs_per_zspage; } =20 +/** + * zs_lookup_class_index() - Returns index of the zsmalloc &size_class + * that hold objects of the provided size. + * @pool: zsmalloc pool to use + * @size: object size + * + * Context: Any context. + * + * Return: the index of the zsmalloc &size_class that hold objects of the + * provided size. + */ +unsigned int zs_lookup_class_index(struct zs_pool *pool, unsigned int size) +{ + struct size_class *class; + + class =3D pool->size_class[get_size_class_index(size)]; + + return class->index; +} +EXPORT_SYMBOL_GPL(zs_lookup_class_index); + unsigned long zs_get_total_pages(struct zs_pool *pool) { return atomic_long_read(&pool->pages_allocated); --=20 2.38.1.431.g37b22c650d-goog From nobody Mon Sep 15 20:41:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 642D5C4332F for ; Wed, 9 Nov 2022 11:51:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229838AbiKILvl (ORCPT ); Wed, 9 Nov 2022 06:51:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230015AbiKILvX (ORCPT ); Wed, 9 Nov 2022 06:51:23 -0500 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3BD9A2EF1D for ; 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charset="utf-8" Size class index comparison is powerful enough so we can remove object size comparisons. Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- drivers/block/zram/zram_drv.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 383d967ef4c7..67b58f2255db 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1725,9 +1725,7 @@ static int zram_recompress(struct zram *zram, u32 ind= ex, struct page *page, comp_len_new); =20 /* Continue until we make progress */ - if (comp_len_new >=3D huge_class_size || - comp_len_new >=3D comp_len_old || - class_index_new >=3D class_index_old || + if (class_index_new >=3D class_index_old || (threshold && comp_len_new >=3D threshold)) { zcomp_stream_put(zram->comps[prio]); continue; @@ -1750,9 +1748,7 @@ static int zram_recompress(struct zram *zram, u32 ind= ex, struct page *page, * that would save memory, mark the object as incompressible so that * we will not try to compress it again. */ - if (comp_len_new >=3D huge_class_size || - comp_len_new >=3D comp_len_old || - class_index_new >=3D class_index_old) { + if (class_index_new >=3D class_index_old) { zram_set_flag(zram, index, ZRAM_INCOMPRESSIBLE); return 0; } --=20 2.38.1.431.g37b22c650d-goog From nobody Mon Sep 15 20:41:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05325C43219 for ; Wed, 9 Nov 2022 11:51:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231210AbiKILvt (ORCPT ); Wed, 9 Nov 2022 06:51:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34710 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230443AbiKILva (ORCPT ); Wed, 9 Nov 2022 06:51:30 -0500 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 56813317DE for ; Wed, 9 Nov 2022 03:51:20 -0800 (PST) Received: by mail-pl1-x62a.google.com with SMTP id io19so16854739plb.8 for ; Wed, 09 Nov 2022 03:51:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=n7l0gcyZTSMtgONlgCq8JYmzNKlzJdwXwSa9TtKzHX4=; b=dCtnfolV7NZTjIQst7bLm+R0e8lXueKVV0v7b/QjyVHeRBIdxnvcnXoOnCxxFDvSvk EwwKsn9H/c3u3wxAH18AuVZrTTGa0xtsRdZ2lQvewblpJv1hQ/BJ1/cVh02T51kqwibA 9TfwfyIhmJ1AFeRqYwaDl6PjbFd3przV0Cnok= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=n7l0gcyZTSMtgONlgCq8JYmzNKlzJdwXwSa9TtKzHX4=; b=c/5Hb3R6dYADGrTTgn3PO5Zg5TRoGCR0bZNueq9tXrc/8O+Vt5uAhSQF4UHQtn4E3B fX+vG62L7V/P9mI6Y5EMXkOJzARWby+E7mt8q/1khebJGROotqe87b5F42ipui1sfzOR a4CinDWNRUvYrFjsDwsWFyfetW4ebBvFwVX4rWrezrjPzq/NqVmGnZGEOJWhdgLLc/Au 2d1QYm0hGLnE71m7jou30sId8UzG9Vt68SWp2g4xaTD1f6eKyhRXeXqvdMhW2kluIH1e Dzgxk5tPe4I/A3ZRer6/D401Pa6ytsfBVrkmlA+Zg9faOcyos/e3sjamyXQjBQ7d6C0x Y9ig== X-Gm-Message-State: ACrzQf2emUEp99M/24i5zognwepUNYDxoRtTUsc+V5DkhCh77pdtlKl8 aeTTuTFN/sFHk1YdV1CkMAnyGg== X-Google-Smtp-Source: AMsMyM7Rg2hU/k1WD6TqY27OHXzxKTED3WjneC0q/KoUbZcCmKt04o1vVWc7COK2SZU7DinwUBf6Tg== X-Received: by 2002:a17:90a:cb03:b0:214:219:b2b9 with SMTP id z3-20020a17090acb0300b002140219b2b9mr48462292pjt.191.1667994680525; Wed, 09 Nov 2022 03:51:20 -0800 (PST) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:61f1:44d3:3f47:2cdb]) by smtp.gmail.com with ESMTPSA id f5-20020a655505000000b00434760ee36asm7292311pgr.16.2022.11.09.03.51.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Nov 2022 03:51:20 -0800 (PST) From: Sergey Senozhatsky To: Minchan Kim , Andrew Morton Cc: Nitin Gupta , Suleiman Souhlal , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sergey Senozhatsky Subject: [PATCHv5 10/13] zram: Add algo parameter support to zram_recompress() Date: Wed, 9 Nov 2022 20:50:44 +0900 Message-Id: <20221109115047.2921851-11-senozhatsky@chromium.org> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <20221109115047.2921851-1-senozhatsky@chromium.org> References: <20221109115047.2921851-1-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Recompression iterates through all the registered secondary compression algorithms in order of their priorities so that we have higher chances of finding the algorithm that compresses a particular page. This, however, may not always be best approach and sometimes we may want to limit recompression to only one particular algorithm. For instance, when a higher priority algorithm uses too much power and device has a relatively low battery level we may want to limit recompression to use only a lower priority algorithm, which uses less power. Introduce algo=3D parameter support to recompression sysfs knob so that user-sapce can request recompression with particular algorithm only: echo "type=3Didle algo=3Dzstd" > /sys/block/zramX/recompress Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- drivers/block/zram/zram_drv.c | 54 +++++++++++++++++++++++++++++------ drivers/block/zram/zram_drv.h | 1 + 2 files changed, 46 insertions(+), 9 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 67b58f2255db..89d25f60b33e 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1677,6 +1677,7 @@ static int zram_recompress(struct zram *zram, u32 ind= ex, struct page *page, unsigned int comp_len_new; unsigned int class_index_old; unsigned int class_index_new; + u32 num_recomps =3D 0; void *src, *dst; int ret; =20 @@ -1711,6 +1712,7 @@ static int zram_recompress(struct zram *zram, u32 ind= ex, struct page *page, if (prio <=3D zram_get_priority(zram, index)) continue; =20 + num_recomps++; zstrm =3D zcomp_stream_get(zram->comps[prio]); src =3D kmap_atomic(page); ret =3D zcomp_compress(zstrm, src, &comp_len_new); @@ -1743,13 +1745,19 @@ static int zram_recompress(struct zram *zram, u32 i= ndex, struct page *page, if (!zstrm) return 0; =20 - /* - * All secondary algorithms failed to re-compress the page in a way - * that would save memory, mark the object as incompressible so that - * we will not try to compress it again. - */ if (class_index_new >=3D class_index_old) { - zram_set_flag(zram, index, ZRAM_INCOMPRESSIBLE); + /* + * Secondary algorithms failed to re-compress the page + * in a way that would save memory, mark the object as + * incompressible so that we will not try to compress + * it again. + * + * We need to make sure that all secondary algorithms have + * failed, so we test if the number of recompressions matches + * the number of active secondary algorithms. + */ + if (num_recomps =3D=3D zram->num_active_comps - 1) + zram_set_flag(zram, index, ZRAM_INCOMPRESSIBLE); return 0; } =20 @@ -1798,10 +1806,11 @@ static ssize_t recompress_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { + u32 prio =3D ZRAM_SECONDARY_COMP, prio_max =3D ZRAM_MAX_COMPS; struct zram *zram =3D dev_to_zram(dev); - u32 mode =3D 0, threshold =3D 0, prio =3D ZRAM_SECONDARY_COMP; unsigned long nr_pages =3D zram->disksize >> PAGE_SHIFT; - char *args, *param, *val; + char *args, *param, *val, *algo =3D NULL; + u32 mode =3D 0, threshold =3D 0; unsigned long index; struct page *page; ssize_t ret; @@ -1833,6 +1842,11 @@ static ssize_t recompress_store(struct device *dev, return ret; continue; } + + if (!strcmp(param, "algo")) { + algo =3D val; + continue; + } } =20 if (threshold >=3D PAGE_SIZE) @@ -1844,6 +1858,26 @@ static ssize_t recompress_store(struct device *dev, goto release_init_lock; } =20 + if (algo) { + bool found =3D false; + + for (; prio < ZRAM_MAX_COMPS; prio++) { + if (!zram->comp_algs[prio]) + continue; + + if (!strcmp(zram->comp_algs[prio], algo)) { + prio_max =3D min(prio + 1, ZRAM_MAX_COMPS); + found =3D true; + break; + } + } + + if (!found) { + ret =3D -EINVAL; + goto release_init_lock; + } + } + page =3D alloc_page(GFP_KERNEL); if (!page) { ret =3D -ENOMEM; @@ -1874,7 +1908,7 @@ static ssize_t recompress_store(struct device *dev, goto next; =20 err =3D zram_recompress(zram, index, page, threshold, - prio, ZRAM_MAX_COMPS); + prio, prio_max); next: zram_slot_unlock(zram, index); if (err) { @@ -2110,6 +2144,7 @@ static void zram_destroy_comps(struct zram *zram) if (!comp) continue; zcomp_destroy(comp); + zram->num_active_comps--; } } =20 @@ -2177,6 +2212,7 @@ static ssize_t disksize_store(struct device *dev, } =20 zram->comps[prio] =3D comp; + zram->num_active_comps++; } zram->disksize =3D disksize; set_capacity_and_notify(zram->disk, zram->disksize >> SECTOR_SHIFT); diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index b80faae76835..473325415a74 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -125,6 +125,7 @@ struct zram { */ u64 disksize; /* bytes */ const char *comp_algs[ZRAM_MAX_COMPS]; + s8 num_active_comps; /* * zram is claimed so open request will be failed */ --=20 2.38.1.431.g37b22c650d-goog From nobody Mon Sep 15 20:41:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8513C433FE for ; Wed, 9 Nov 2022 11:52:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231248AbiKILwc (ORCPT ); Wed, 9 Nov 2022 06:52:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35228 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231232AbiKILvc (ORCPT ); Wed, 9 Nov 2022 06:51:32 -0500 Received: from mail-pf1-x429.google.com (mail-pf1-x429.google.com [IPv6:2607:f8b0:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A8FBA31216 for ; Wed, 9 Nov 2022 03:51:23 -0800 (PST) Received: by mail-pf1-x429.google.com with SMTP id v28so16444082pfi.12 for ; 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charset="utf-8" Document user-space visible device attributes that are enabled by ZRAM_MULTI_COMP. Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- Documentation/admin-guide/blockdev/zram.rst | 81 +++++++++++++++++++++ 1 file changed, 81 insertions(+) diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/ad= min-guide/blockdev/zram.rst index 177a142c3146..d898b7ace33d 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -401,6 +401,87 @@ budget in next setting is user's job. If admin wants to measure writeback count in a certain period, they could know it via /sys/block/zram0/bd_stat's 3rd column. =20 +recompression +------------- + +With CONFIG_ZRAM_MULTI_COMP, zram can recompress pages using alternative +(secondary) compression algorithms. The basic idea is that alternative +compression algorithm can provide better compression ratio at a price of +(potentially) slower compression/decompression speeds. Alternative compres= sion +algorithm can, for example, be more successful compressing huge pages (tho= se +that default algorithm failed to compress). Another application is idle pa= ges +recompression - pages that are cold and sit in the memory can be recompres= sed +using more effective algorithm and, hence, reduce zsmalloc memory usage. + +With CONFIG_ZRAM_MULTI_COMP, zram supports up to 4 compression algorithms: +one primary and up to 3 secondary ones. Primary zram compressor is explain= ed +in "3) Select compression algorithm", secondary algorithms are configured +using recomp_algorithm device attribute. + +Example::: + + #show supported recompression algorithms + cat /sys/block/zramX/recomp_algorithm + #1: lzo lzo-rle lz4 lz4hc [zstd] + #2: lzo lzo-rle lz4 [lz4hc] zstd + +Alternative compression algorithms are sorted by priority. In the example +above, zstd is used as the first alternative algorithm, which has priority +of 1, while lz4hc is configured as a compression algorithm with priority 2. +Alternative compression algorithm's priority is provided during algorithms +configuration::: + + #select zstd recompression algorithm, priority 1 + echo "algo=3Dzstd priority=3D1" > /sys/block/zramX/recomp_algorithm + + #select deflate recompression algorithm, priority 2 + echo "algo=3Ddeflate priority=3D2" > /sys/block/zramX/recomp_algorithm + +Another device attribute that CONFIG_ZRAM_MULTI_COMP enables is recompress, +which controls recompression. + +Examples::: + + #IDLE pages recompression is activated by `idle` mode + echo "type=3Didle" > /sys/block/zramX/recompress + + #HUGE pages recompression is activated by `huge` mode + echo "type=3Dhuge" > /sys/block/zram0/recompress + + #HUGE_IDLE pages recompression is activated by `huge_idle` mode + echo "type=3Dhuge_idle" > /sys/block/zramX/recompress + +The number of idle pages can be significant, so user-space can pass a size +threshold (in bytes) to the recompress knob: zram will recompress only pag= es +of equal or greater size::: + + #recompress all pages larger than 3000 bytes + echo "threshold=3D3000" > /sys/block/zramX/recompress + + #recompress idle pages larger than 2000 bytes + echo "type=3Didle threshold=3D2000" > /sys/block/zramX/recompress + +Recompression of idle pages requires memory tracking. + +During re-compression for every page, that matches re-compression criteria, +ZRAM iterates the list of registered alternative compression algorithms in +order of their priorities. ZRAM stops either when re-compression was +successful (re-compressed object is smaller in size than the original one) +and matches re-compression criteria (e.g. size threshold) or when there are +no secondary algorithms left to try. If none of the secondary algorithms c= an +successfully re-compressed the page such a page is marked as incompressibl= e, +so ZRAM will not attempt to re-compress it in the future. + +This re-compression behaviour, when it iterates through the list of +registered compression algorithms, increases our chances of finding the +algorithm that successfully compresses a particular page. Sometimes, howev= er, +it is convenient (and sometimes even necessary) to limit recompression to +only one particular algorithm so that it will not try any other algorithms. +This can be achieved by providing a algo=3DNAME parameter::: + + #use zstd algorithm only (if registered) + echo "type=3Dhuge algo=3Dzstd" > /sys/block/zramX/recompress + memory tracking =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =20 --=20 2.38.1.431.g37b22c650d-goog From nobody Mon Sep 15 20:41:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A59A4C433FE for ; Wed, 9 Nov 2022 11:52:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230141AbiKILwT (ORCPT ); Wed, 9 Nov 2022 06:52:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230475AbiKILvd (ORCPT ); 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Wed, 09 Nov 2022 03:51:25 -0800 (PST) From: Sergey Senozhatsky To: Minchan Kim , Andrew Morton Cc: Nitin Gupta , Suleiman Souhlal , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sergey Senozhatsky Subject: [PATCHv5 12/13] zram: add incompressible writeback Date: Wed, 9 Nov 2022 20:50:46 +0900 Message-Id: <20221109115047.2921851-13-senozhatsky@chromium.org> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <20221109115047.2921851-1-senozhatsky@chromium.org> References: <20221109115047.2921851-1-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add support for incompressible pages writeback: echo incompressible > /sys/block/zramX/writeback Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- Documentation/admin-guide/blockdev/zram.rst | 7 ++++++- drivers/block/zram/zram_drv.c | 18 ++++++++++++------ 2 files changed, 18 insertions(+), 7 deletions(-) diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/ad= min-guide/blockdev/zram.rst index d898b7ace33d..f14c8c2e42f3 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -348,8 +348,13 @@ this can be accomplished with:: =20 echo huge_idle > /sys/block/zramX/writeback =20 +If a user chooses to writeback only incompressible pages (pages that none = of +algorithms can compress) this can be accomplished with:: + + echo incompressible > /sys/block/zramX/writeback + If an admin wants to write a specific page in zram device to the backing d= evice, -they could write a page index into the interface. +they could write a page index into the interface:: =20 echo "page_index=3D1251" > /sys/block/zramX/writeback =20 diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 89d25f60b33e..2e4ef1ba1973 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -648,10 +648,10 @@ static int read_from_bdev_async(struct zram *zram, st= ruct bio_vec *bvec, =20 #define PAGE_WB_SIG "page_index=3D" =20 -#define PAGE_WRITEBACK 0 -#define HUGE_WRITEBACK (1<<0) -#define IDLE_WRITEBACK (1<<1) - +#define PAGE_WRITEBACK 0 +#define HUGE_WRITEBACK (1<<0) +#define IDLE_WRITEBACK (1<<1) +#define INCOMPRESSIBLE_WRITEBACK (1<<2) =20 static ssize_t writeback_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) @@ -672,6 +672,8 @@ static ssize_t writeback_store(struct device *dev, mode =3D HUGE_WRITEBACK; else if (sysfs_streq(buf, "huge_idle")) mode =3D IDLE_WRITEBACK | HUGE_WRITEBACK; + else if (sysfs_streq(buf, "incompressible")) + mode =3D INCOMPRESSIBLE_WRITEBACK; else { if (strncmp(buf, PAGE_WB_SIG, sizeof(PAGE_WB_SIG) - 1)) return -EINVAL; @@ -734,11 +736,15 @@ static ssize_t writeback_store(struct device *dev, goto next; =20 if (mode & IDLE_WRITEBACK && - !zram_test_flag(zram, index, ZRAM_IDLE)) + !zram_test_flag(zram, index, ZRAM_IDLE)) goto next; if (mode & HUGE_WRITEBACK && - !zram_test_flag(zram, index, ZRAM_HUGE)) + !zram_test_flag(zram, index, ZRAM_HUGE)) goto next; + if (mode & INCOMPRESSIBLE_WRITEBACK && + !zram_test_flag(zram, index, ZRAM_INCOMPRESSIBLE)) + goto next; + /* * Clearing ZRAM_UNDER_WB is duty of caller. * IOW, zram_free_page never clear it. --=20 2.38.1.431.g37b22c650d-goog From nobody Mon Sep 15 20:41:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E08FC4332F for ; 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Wed, 09 Nov 2022 03:51:27 -0800 (PST) From: Sergey Senozhatsky To: Minchan Kim , Andrew Morton Cc: Nitin Gupta , Suleiman Souhlal , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sergey Senozhatsky Subject: [PATCHv5 13/13] zram: Add incompressible flag to read_block_state() Date: Wed, 9 Nov 2022 20:50:47 +0900 Message-Id: <20221109115047.2921851-14-senozhatsky@chromium.org> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <20221109115047.2921851-1-senozhatsky@chromium.org> References: <20221109115047.2921851-1-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add a new flag to zram block state that shows if the page is incompressible: that none of the algorithm (including secondary ones) could compress it. Suggested-by: Minchan Kim Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim --- Documentation/admin-guide/blockdev/zram.rst | 11 +++++++---- drivers/block/zram/zram_drv.c | 6 ++++-- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/ad= min-guide/blockdev/zram.rst index f14c8c2e42f3..e4551579cb12 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -497,10 +497,11 @@ pages of the process with*pagemap. If you enable the feature, you could see block state via /sys/kernel/debug/zram/zram0/block_state". The output is as follows:: =20 - 300 75.033841 .wh.. - 301 63.806904 s.... - 302 63.806919 ..hi. - 303 62.801919 ....r + 300 75.033841 .wh... + 301 63.806904 s..... + 302 63.806919 ..hi.. + 303 62.801919 ....r. + 304 146.781902 ..hi.n =20 First column zram's block index. @@ -519,6 +520,8 @@ Third column idle page r: recompressed page (secondary compression algorithm) + n: + none (including secondary) of algorithms could compress it =20 First line of above example says 300th block is accessed at 75.033841sec and the block's state is huge so it is written back to the backing diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 2e4ef1ba1973..3447df3ca75e 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -949,14 +949,16 @@ static ssize_t read_block_state(struct file *file, ch= ar __user *buf, =20 ts =3D ktime_to_timespec64(zram->table[index].ac_time); copied =3D snprintf(kbuf + written, count, - "%12zd %12lld.%06lu %c%c%c%c%c\n", + "%12zd %12lld.%06lu %c%c%c%c%c%c\n", index, (s64)ts.tv_sec, ts.tv_nsec / NSEC_PER_USEC, zram_test_flag(zram, index, ZRAM_SAME) ? 's' : '.', zram_test_flag(zram, index, ZRAM_WB) ? 'w' : '.', zram_test_flag(zram, index, ZRAM_HUGE) ? 'h' : '.', zram_test_flag(zram, index, ZRAM_IDLE) ? 'i' : '.', - zram_get_priority(zram, index) ? 'r' : '.'); + zram_get_priority(zram, index) ? 'r' : '.', + zram_test_flag(zram, index, + ZRAM_INCOMPRESSIBLE) ? 'n' : '.'); =20 if (count <=3D copied) { zram_slot_unlock(zram, index); --=20 2.38.1.431.g37b22c650d-goog