From patchwork Mon Aug 29 13:23:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liu Shixin X-Patchwork-Id: 12957730 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7FD4FECAAD5 for ; Mon, 29 Aug 2022 12:48:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6DDD294000C; Mon, 29 Aug 2022 08:48:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6663394000B; Mon, 29 Aug 2022 08:48:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5071994000C; Mon, 29 Aug 2022 08:48:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 3E03294000B for ; Mon, 29 Aug 2022 08:48:41 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 158A9140A19 for ; Mon, 29 Aug 2022 12:48:41 +0000 (UTC) X-FDA: 79852609242.26.B6C1826 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf10.hostedemail.com (Postfix) with ESMTP id 472D0C0009 for ; Mon, 29 Aug 2022 12:48:40 +0000 (UTC) Received: from dggpemm500020.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MGVYJ4xwJznTs4; Mon, 29 Aug 2022 20:46:12 +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; Mon, 29 Aug 2022 20:48:37 +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; Mon, 29 Aug 2022 20:48:35 +0800 From: Liu Shixin To: Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton , Nathan Chancellor , "Christoph Hellwig" CC: , , Liu Shixin , Kefeng Wang Subject: [PATCH -next v4 5/6] mm/zswap: delay the initializaton of zswap until the first enablement Date: Mon, 29 Aug 2022 21:23:01 +0800 Message-ID: <20220829132302.3367054-6-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220829132302.3367054-1-liushixin2@huawei.com> References: <20220829132302.3367054-1-liushixin2@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm100009.china.huawei.com (7.185.36.113) X-CFilter-Loop: Reflected ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1661777320; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=19EKXasTmXdQPu6nrwmMY0Dk2rArbRm/aRTZk/dMR5Y=; b=b8+4ACP+J0rOSNNFYudjnnxUuCHoDqpEXlsyQBzDCFZceQuuqNKND3iJbL8txGuhmnRs8e oHVDhFrMiI9S6pjpy47izGxYcKsOfU54985b3n4BQT6bIL5MmFPXbYOkgeIuQYIzmQkOxm dFhEMeTdCLeb8wIFWs/vmjpPJimQH6o= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=none; spf=pass (imf10.hostedemail.com: domain of liushixin2@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=liushixin2@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1661777320; a=rsa-sha256; cv=none; b=CLWVNovHqt6YSiixqQNqtQAaH5ve8HbGOacKm/TnhcMTF5GU+yHg06VpFT7F5pFkEE8v5G SVGcZvHeS1rqG1E9GE5FQS8kZaWwaBB8zJ+aKizr2OUOHB2RadyRg+0nkv5i9XL/deLQ4F 0iK9XeLYxFc/fLAxtk5bubbnqEOZl6o= Authentication-Results: imf10.hostedemail.com; dkim=none; spf=pass (imf10.hostedemail.com: domain of liushixin2@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=liushixin2@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-Rspamd-Server: rspam06 X-Rspam-User: X-Rspamd-Queue-Id: 472D0C0009 X-Stat-Signature: fzafr5dmrtayxpyqugwafzc18jucqfz3 X-HE-Tag: 1661777320-293044 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 | 50 ++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 40 insertions(+), 10 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index 155aee785a16..dac1714c7eda 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -81,6 +81,8 @@ static bool zswap_pool_reached_full; #define ZSWAP_PARAM_UNSET "" +static int zswap_setup(void); + /* Enable/disable zswap */ static bool zswap_enabled = IS_ENABLED(CONFIG_ZSWAP_DEFAULT_ON); static int zswap_enabled_param_set(const char *, @@ -220,6 +222,8 @@ static atomic_t zswap_pools_count = ATOMIC_INIT(0); /* init state */ static int zswap_init_state; +/* used to ensure the integrity of initialization */ +static DEFINE_MUTEX(zswap_init_lock); /* 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; -static int __init zswap_entry_cache_create(void) +static int zswap_entry_cache_create(void) { zswap_entry_cache = KMEM_CACHE(zswap_entry, 0); return zswap_entry_cache == NULL; } -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; } -static __init struct zswap_pool *__zswap_pool_create_fallback(void) +static struct zswap_pool *__zswap_pool_create_fallback(void) { bool has_comp, has_zpool; @@ -782,11 +786,17 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp, if (!strcmp(s, *(char **)kp->arg) && zswap_has_pool) return 0; - /* 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 == ZSWAP_UNINIT) - return param_set_charp(s, kp); + mutex_lock(&zswap_init_lock); + if (zswap_init_state == ZSWAP_UNINIT) { + ret = param_set_charp(s, kp); + mutex_unlock(&zswap_init_lock); + return ret; + } + mutex_unlock(&zswap_init_lock); 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 == 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 == ZSWAP_INIT_FAILED) { pr_err("can't enable, initialization failed\n"); return -ENODEV; @@ -1432,7 +1450,7 @@ static struct frontswap_ops zswap_frontswap_ops = { static struct dentry *zswap_debugfs_root; -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; + if (zswap_init_state != ZSWAP_UNINIT) + return 0; + if (zswap_entry_cache_create()) { pr_err("entry cache creation failed\n"); goto cache_fail; @@ -1530,8 +1551,17 @@ static int __init init_zswap(void) zswap_enabled = false; return -ENOMEM; } + +static int __init zswap_init(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); +late_initcall(zswap_init); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Seth Jennings ");