From nobody Wed Apr 8 14:10:36 2026 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 D6BBFECDFA1 for ; Wed, 26 Oct 2022 11:30:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233155AbiJZLaV (ORCPT ); Wed, 26 Oct 2022 07:30:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232844AbiJZLaN (ORCPT ); Wed, 26 Oct 2022 07:30:13 -0400 Received: from mail-pg1-x534.google.com (mail-pg1-x534.google.com [IPv6:2607:f8b0:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C6452B273 for ; Wed, 26 Oct 2022 04:30:12 -0700 (PDT) Received: by mail-pg1-x534.google.com with SMTP id 128so14498520pga.1 for ; Wed, 26 Oct 2022 04:30:12 -0700 (PDT) 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=9cCehdWYmf2oT/+c3VC1U3PDElTtgIhBCXz1ANz8y7s=; b=GhNKrg0OAEwZop9TkQkoF/GYEB52Wp+FIXuigMbvdSHs2wjHSdWGVy+2RWGpHitcRZ GGEFJKQi4EZOQyUw0VThpPDdexrgvdZenXB8pA6s3yQsqgoPQ3jA02EQjZ513REHymHw eHeOgtudRK/s72eVGFn75SujwAATGHhrMKr7U= 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=9cCehdWYmf2oT/+c3VC1U3PDElTtgIhBCXz1ANz8y7s=; b=j8CDqzktP9HuivvTYbCfxCXEDxPbwcVlL1r6+g2KHt7lwnWjO7VL6S2dGK+T8/HjE6 vJLhPlDMoWmS8Fe6OLzQ+GBYiaSNIIH3wY8EKSArPAM95OAjfyEA53zGRhDkmoYwNnfa 3e03bLV5vsgQMzSK4yCEhygOz1CcVBzNaYYz/co/8sbe0KlzCr99UN31MCTaPizYuyFN O8MXlFOd/f3LfL56+h2z0ij5Ai9l6ef8GttUzKuzQRYJ21a9UDegn8KHtGQR8YHp2oHQ bKEAvEzsARRkTBmVKo+D360Xnbvqvq0936V+Ah3IuYkdoTg2VKkdqlazrxcijY8cIQLA 0lzQ== X-Gm-Message-State: ACrzQf0R+X+VuihDERZAInupZs4YHmIItmSZGk4qHEoTJ7hnHM+PJ5PB yXBMYgDmdEoQt4DgJrQRb2azPg== X-Google-Smtp-Source: AMsMyM7Q4/e+y7mw0PklcMKgFBOK8szlLFKFKA9a8e/xiHIZ2p93fMqJppuuw1/722a3mQ94k0Z3xA== X-Received: by 2002:a05:6a00:1688:b0:53b:4239:7c5c with SMTP id k8-20020a056a00168800b0053b42397c5cmr44419098pfc.81.1666783811869; Wed, 26 Oct 2022 04:30:11 -0700 (PDT) Received: from tigerii.tok.corp.google.com ([2401:fa00:8f:203:749c:f7f5:1a8e:d0be]) by smtp.gmail.com with ESMTPSA id x127-20020a626385000000b005627868e27esm2814919pfb.127.2022.10.26.04.30.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Oct 2022 04:30:11 -0700 (PDT) From: Sergey Senozhatsky To: Andrew Morton , Minchan Kim Cc: Nitin Gupta , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Alexey Romanov , Sergey Senozhatsky Subject: [PATCHv2 1/9] zram: add size class equals check into recompression Date: Wed, 26 Oct 2022 20:29:25 +0900 Message-Id: <20221026112933.4122957-2-senozhatsky@chromium.org> X-Mailer: git-send-email 2.38.0.135.g90850a2211-goog In-Reply-To: <20221026112933.4122957-1-senozhatsky@chromium.org> References: <20221026112933.4122957-1-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. Signed-off-by: Alexey Romanov Reviewed-by: Sergey Senozhatsky --- drivers/block/zram/zram_drv.c | 5 +++++ include/linux/zsmalloc.h | 2 ++ mm/zsmalloc.c | 21 +++++++++++++++++++++ 3 files changed, 28 insertions(+) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 364323713393..fd31beb6491a 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1632,6 +1632,8 @@ static int zram_recompress(struct zram *zram, u32 ind= ex, struct page *page, unsigned long handle_next; unsigned int comp_len_next; unsigned int comp_len_prev; + unsigned int class_index_prev; + unsigned int class_index_next; struct zcomp_strm *zstrm; void *src, *dst; int ret; @@ -1656,6 +1658,8 @@ static int zram_recompress(struct zram *zram, u32 ind= ex, struct page *page, ret =3D zcomp_compress(zstrm, src, &comp_len_next); kunmap_atomic(src); =20 + class_index_prev =3D zs_lookup_class_index(zram->mem_pool, comp_len_prev); + class_index_next =3D zs_lookup_class_index(zram->mem_pool, comp_len_next); /* * Either a compression error or we failed to compressed the object * in a way that will save us memory. Mark the object so that we @@ -1663,6 +1667,7 @@ static int zram_recompress(struct zram *zram, u32 ind= ex, struct page *page, */ if (comp_len_next >=3D huge_class_size || comp_len_next >=3D comp_len_prev || + class_index_next >=3D class_index_prev || ret) { zram_set_flag(zram, index, ZRAM_RECOMP_SKIP); zram_clear_flag(zram, index, ZRAM_IDLE); 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 2.38.0.135.g90850a2211-goog