From nobody Tue Apr 7 18:09:43 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 B4E27C28D13 for ; Thu, 25 Aug 2022 13:46:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242696AbiHYNqO (ORCPT ); Thu, 25 Aug 2022 09:46:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240614AbiHYNqD (ORCPT ); Thu, 25 Aug 2022 09:46:03 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 263F02CDC6 for ; Thu, 25 Aug 2022 06:46:00 -0700 (PDT) Received: from dggpemm500021.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4MD40L2lhxzlWTx; Thu, 25 Aug 2022 21:42:42 +0800 (CST) Received: from dggpemm100009.china.huawei.com (7.185.36.113) by dggpemm500021.china.huawei.com (7.185.36.109) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 25 Aug 2022 21:45:58 +0800 Received: from huawei.com (10.175.113.32) by dggpemm100009.china.huawei.com (7.185.36.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 25 Aug 2022 21:45:57 +0800 From: Liu Shixin To: Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton CC: , , Liu Shixin Subject: [PATCH -next 1/3] mm/zswap: replace zswap_init_{started/failed} with zswap_init_state Date: Thu, 25 Aug 2022 22:20:35 +0800 Message-ID: <20220825142037.3214152-2-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220825142037.3214152-1-liushixin2@huawei.com> References: <20220825142037.3214152-1-liushixin2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm100009.china.huawei.com (7.185.36.113) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" zswap_init_started indicates that the initialization is started. And zswap_init_failed indicates that the initialization is failed. As we will support to init zswap after system startup, it's necessary to add a state to indicate the initialization is complete and succeed to avoid concurrency issues. Since we don't care about the difference between init started with init completion. We only need three states: uninitialized, initial failed, initial succeed. Signed-off-by: Liu Shixin --- mm/zswap.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index 2d48fd59cc7a..84e38300f571 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -214,11 +214,12 @@ static DEFINE_SPINLOCK(zswap_pools_lock); /* pool counter to provide unique names to zpool */ static atomic_t zswap_pools_count =3D ATOMIC_INIT(0); =20 -/* used by param callback function */ -static bool zswap_init_started; +#define ZSWAP_UNINIT 0 +#define ZSWAP_INIT_SUCCEED 1 +#define ZSWAP_INIT_FAILED 2 =20 -/* fatal error during init */ -static bool zswap_init_failed; +/* init state */ +static int zswap_init_state; =20 /* init completed, but couldn't create the initial pool */ static bool zswap_has_pool; @@ -772,7 +773,7 @@ static int __zswap_param_set(const char *val, const str= uct kernel_param *kp, char *s =3D strstrip((char *)val); int ret; =20 - if (zswap_init_failed) { + if (zswap_init_state =3D=3D ZSWAP_INIT_FAILED) { pr_err("can't set param, initialization failed\n"); return -ENODEV; } @@ -784,7 +785,7 @@ static int __zswap_param_set(const char *val, const str= uct kernel_param *kp, /* if this is load-time (pre-init) param setting, * don't create a pool; that's done during init. */ - if (!zswap_init_started) + if (zswap_init_state =3D=3D ZSWAP_UNINIT) return param_set_charp(s, kp); =20 if (!type) { @@ -875,11 +876,11 @@ static int zswap_zpool_param_set(const char *val, static int zswap_enabled_param_set(const char *val, const struct kernel_param *kp) { - if (zswap_init_failed) { + if (zswap_init_state =3D=3D ZSWAP_INIT_FAILED) { pr_err("can't enable, initialization failed\n"); return -ENODEV; } - if (!zswap_has_pool && zswap_init_started) { + if (!zswap_has_pool && zswap_init_state =3D=3D ZSWAP_INIT_SUCCEED) { pr_err("can't enable, no pool configured\n"); return -ENODEV; } @@ -1476,8 +1477,6 @@ static int __init init_zswap(void) struct zswap_pool *pool; int ret; =20 - zswap_init_started =3D true; - if (zswap_entry_cache_create()) { pr_err("entry cache creation failed\n"); goto cache_fail; @@ -1517,6 +1516,7 @@ static int __init init_zswap(void) goto destroy_wq; if (zswap_debugfs_init()) pr_warn("debugfs initialization failed\n"); + zswap_init_state =3D ZSWAP_INIT_SUCCEED; return 0; =20 destroy_wq: @@ -1530,7 +1530,7 @@ static int __init init_zswap(void) zswap_entry_cache_destroy(); cache_fail: /* if built-in, we aren't unloaded on failure; don't allow use */ - zswap_init_failed =3D true; + zswap_init_state =3D ZSWAP_INIT_FAILED; zswap_enabled =3D false; return -ENOMEM; } --=20 2.25.1 From nobody Tue Apr 7 18:09:43 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 7D65FC28D13 for ; Thu, 25 Aug 2022 13:46:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242779AbiHYNqV (ORCPT ); Thu, 25 Aug 2022 09:46:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38328 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241787AbiHYNqD (ORCPT ); Thu, 25 Aug 2022 09:46:03 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 262932CC86 for ; Thu, 25 Aug 2022 06:46:00 -0700 (PDT) Received: from dggpemm500020.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MD4024WzdzkWcm; Thu, 25 Aug 2022 21:42:26 +0800 (CST) Received: from dggpemm100009.china.huawei.com (7.185.36.113) by dggpemm500020.china.huawei.com (7.185.36.49) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 25 Aug 2022 21:45:58 +0800 Received: from huawei.com (10.175.113.32) by dggpemm100009.china.huawei.com (7.185.36.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 25 Aug 2022 21:45:57 +0800 From: Liu Shixin To: Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton CC: , , Liu Shixin Subject: [PATCH -next 2/3] mm/zswap: delay the initializaton of zswap until the first enablement Date: Thu, 25 Aug 2022 22:20:36 +0800 Message-ID: <20220825142037.3214152-3-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220825142037.3214152-1-liushixin2@huawei.com> References: <20220825142037.3214152-1-liushixin2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm100009.china.huawei.com (7.185.36.113) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" In the initialization of zswap, about 18MB memory will be allocated for zswap_pool in my machine. Since not all users use zswap, the memory may be wasted. Save the memory for these users by delaying the initialization of zswap to first enablement. Signed-off-by: Liu Shixin --- mm/zswap.c | 48 +++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 39 insertions(+), 9 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index 84e38300f571..90df72aceb08 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -81,6 +81,8 @@ static bool zswap_pool_reached_full; =20 #define ZSWAP_PARAM_UNSET "" =20 +static int zswap_setup(void); + /* Enable/disable zswap */ static bool zswap_enabled =3D IS_ENABLED(CONFIG_ZSWAP_DEFAULT_ON); static int zswap_enabled_param_set(const char *, @@ -220,6 +222,8 @@ static atomic_t zswap_pools_count =3D ATOMIC_INIT(0); =20 /* init state */ static int zswap_init_state; +/* used to ensure the integrity of initialization */ +static DEFINE_MUTEX(zswap_init_lock); =20 /* init completed, but couldn't create the initial pool */ static bool zswap_has_pool; @@ -273,13 +277,13 @@ static void zswap_update_total_size(void) **********************************/ static struct kmem_cache *zswap_entry_cache; =20 -static int __init zswap_entry_cache_create(void) +static int zswap_entry_cache_create(void) { zswap_entry_cache =3D KMEM_CACHE(zswap_entry, 0); return zswap_entry_cache =3D=3D NULL; } =20 -static void __init zswap_entry_cache_destroy(void) +static void zswap_entry_cache_destroy(void) { kmem_cache_destroy(zswap_entry_cache); } @@ -664,7 +668,7 @@ static struct zswap_pool *zswap_pool_create(char *type,= char *compressor) return NULL; } =20 -static __init struct zswap_pool *__zswap_pool_create_fallback(void) +static struct zswap_pool *__zswap_pool_create_fallback(void) { bool has_comp, has_zpool; =20 @@ -782,11 +786,17 @@ static int __zswap_param_set(const char *val, const s= truct kernel_param *kp, if (!strcmp(s, *(char **)kp->arg) && zswap_has_pool) return 0; =20 - /* if this is load-time (pre-init) param setting, + /* + * if zswap has not been initialized, * don't create a pool; that's done during init. */ - if (zswap_init_state =3D=3D ZSWAP_UNINIT) - return param_set_charp(s, kp); + mutex_lock(&zswap_init_lock); + if (zswap_init_state =3D=3D ZSWAP_UNINIT) { + ret =3D param_set_charp(s, kp); + mutex_unlock(&zswap_init_lock); + return ret; + } + mutex_unlock(&zswap_init_lock); =20 if (!type) { if (!zpool_has_pool(s)) { @@ -876,6 +886,14 @@ static int zswap_zpool_param_set(const char *val, static int zswap_enabled_param_set(const char *val, const struct kernel_param *kp) { + if (system_state =3D=3D SYSTEM_RUNNING) { + mutex_lock(&zswap_init_lock); + if (zswap_setup()) { + mutex_unlock(&zswap_init_lock); + return -ENODEV; + } + mutex_unlock(&zswap_init_lock); + } if (zswap_init_state =3D=3D ZSWAP_INIT_FAILED) { pr_err("can't enable, initialization failed\n"); return -ENODEV; @@ -1432,7 +1450,7 @@ static const struct frontswap_ops zswap_frontswap_ops= =3D { =20 static struct dentry *zswap_debugfs_root; =20 -static int __init zswap_debugfs_init(void) +static int zswap_debugfs_init(void) { if (!debugfs_initialized()) return -ENODEV; @@ -1463,7 +1481,7 @@ static int __init zswap_debugfs_init(void) return 0; } #else -static int __init zswap_debugfs_init(void) +static int zswap_debugfs_init(void) { return 0; } @@ -1472,11 +1490,14 @@ static int __init zswap_debugfs_init(void) /********************************* * module init and exit **********************************/ -static int __init init_zswap(void) +static int zswap_setup(void) { struct zswap_pool *pool; int ret; =20 + if (zswap_init_state !=3D ZSWAP_UNINIT) + return 0; + if (zswap_entry_cache_create()) { pr_err("entry cache creation failed\n"); goto cache_fail; @@ -1534,6 +1555,15 @@ static int __init init_zswap(void) zswap_enabled =3D false; return -ENOMEM; } + +static int __init init_zswap(void) +{ + /* skip init if zswap is disabled when system startup */ + if (!zswap_enabled) + return 0; + return zswap_setup(); +} + /* must be late so crypto has time to come up */ late_initcall(init_zswap); =20 --=20 2.25.1 From nobody Tue Apr 7 18:09:43 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 34E89C65C0D for ; Thu, 25 Aug 2022 13:46:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242519AbiHYNqG (ORCPT ); Thu, 25 Aug 2022 09:46:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38328 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232805AbiHYNqD (ORCPT ); Thu, 25 Aug 2022 09:46:03 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25F2A26123 for ; Thu, 25 Aug 2022 06:46:01 -0700 (PDT) Received: from dggpemm500022.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4MD40M0Dn2zlWWy; Thu, 25 Aug 2022 21:42:43 +0800 (CST) Received: from dggpemm100009.china.huawei.com (7.185.36.113) by dggpemm500022.china.huawei.com (7.185.36.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 25 Aug 2022 21:45:58 +0800 Received: from huawei.com (10.175.113.32) by dggpemm100009.china.huawei.com (7.185.36.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 25 Aug 2022 21:45:58 +0800 From: Liu Shixin To: Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton CC: , , Liu Shixin Subject: [PATCH -next 3/3] mm/zswap: skip confusing print info Date: Thu, 25 Aug 2022 22:20:37 +0800 Message-ID: <20220825142037.3214152-4-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220825142037.3214152-1-liushixin2@huawei.com> References: <20220825142037.3214152-1-liushixin2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm100009.china.huawei.com (7.185.36.113) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" It's confusing when we disable zswap while zswap is init failed or has no pool. If no change required, just return directly. Signed-off-by: Liu Shixin --- mm/zswap.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/zswap.c b/mm/zswap.c index 90df72aceb08..fdf376f239fd 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -886,6 +886,15 @@ static int zswap_zpool_param_set(const char *val, static int zswap_enabled_param_set(const char *val, const struct kernel_param *kp) { + bool res; + + if (kstrtobool(val, &res)) + return -EINVAL; + + /* no change required */ + if (res =3D=3D *(bool *)kp->arg) + return 0; + if (system_state =3D=3D SYSTEM_RUNNING) { mutex_lock(&zswap_init_lock); if (zswap_setup()) { --=20 2.25.1