From mboxrd@z Thu Jan 1 00:00:00 1970 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 D2663C6FD1C for ; Wed, 22 Mar 2023 09:30:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230512AbjCVJ3v (ORCPT ); Wed, 22 Mar 2023 05:29:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230491AbjCVJ3i (ORCPT ); Wed, 22 Mar 2023 05:29:38 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C776559439 for ; Wed, 22 Mar 2023 02:29:27 -0700 (PDT) Received: from dggpemm100009.china.huawei.com (unknown [172.30.72.54]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4PhNQ32plkz17MRb; Wed, 22 Mar 2023 17:26:19 +0800 (CST) 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 15.1.2507.21; Wed, 22 Mar 2023 17:29:25 +0800 From: Liu Shixin To: Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton , Nathan Chancellor , Christoph Hellwig CC: , , Liu Shixin Subject: [PATCH -next v6 2/2] mm/zswap: delay the initializaton of zswap Date: Wed, 22 Mar 2023 18:20:06 +0800 Message-ID: <20230322102006.780624-3-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230322102006.780624-1-liushixin2@huawei.com> References: <20230322102006.780624-1-liushixin2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) 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 Since some users may not use zswap, the zswap_pool is wasted. Save memory by delaying the initialization of zswap until enabled. Signed-off-by: Liu Shixin --- mm/zswap.c | 51 +++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 41 insertions(+), 10 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index 09fa956920fa..3aed3b26524a 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 +222,9 @@ static bool zswap_init_started; /* fatal error during init */ static bool zswap_init_failed; +/* 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; @@ -272,13 +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); } @@ -663,7 +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; @@ -784,8 +789,15 @@ static int __zswap_param_set(const char *val, const struct 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) - return param_set_charp(s, kp); + if (!zswap_init_started) { + mutex_lock(&zswap_init_lock); + if (!zswap_init_started) { + 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)) { @@ -884,6 +896,15 @@ static int zswap_enabled_param_set(const char *val, if (res == *(bool *)kp->arg) return 0; + if (!zswap_init_started && (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_failed) { pr_err("can't enable, initialization failed\n"); return -ENODEV; @@ -1451,7 +1472,7 @@ static const 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; @@ -1482,7 +1503,7 @@ 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; } @@ -1491,12 +1512,13 @@ 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; - zswap_init_started = true; + if (zswap_init_started) + return 0; if (zswap_entry_cache_create()) { pr_err("entry cache creation failed\n"); @@ -1537,6 +1559,7 @@ static int __init init_zswap(void) goto destroy_wq; if (zswap_debugfs_init()) pr_warn("debugfs initialization failed\n"); + zswap_init_started = true; return 0; destroy_wq: @@ -1551,11 +1574,19 @@ static int __init init_zswap(void) cache_fail: /* if built-in, we aren't unloaded on failure; don't allow use */ zswap_init_failed = true; + zswap_init_started = true; zswap_enabled = false; return -ENOMEM; } + +static int __init zswap_init(void) +{ + 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 "); -- 2.25.1