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 AF45CECAAD1 for ; Fri, 26 Aug 2022 02:02:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244501AbiHZCCG (ORCPT ); Thu, 25 Aug 2022 22:02:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44770 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244634AbiHZCCE (ORCPT ); Thu, 25 Aug 2022 22:02:04 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 900A3CAC69 for ; Thu, 25 Aug 2022 19:02:02 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 1A73FB82F68 for ; Fri, 26 Aug 2022 02:02:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B0904C433D6; Fri, 26 Aug 2022 02:01:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1661479319; bh=YQGnStRuJwS9r6c1aPWeCu3Ya0wPlmPbeuBke7NPWqk=; h=Date:To:From:Subject:From; b=XxbThyglnzwoml/1aGyWyajGJBNglzh1rFkJ0Zpn8ke0ZcJsukvkSgkc47hJ+VwxM Zp9tQOxPR1el7pCoDDmoQo95IV1/cxNd/c67FOCBD1Vj0X9LHTJwlponBC3pICAUh/ YZZ1iJVlZ7TRGr5pxpKeYut0z99vjVgNV2DFkM/E= Date: Thu, 25 Aug 2022 19:01:58 -0700 To: mm-commits@vger.kernel.org, vitaly.wool@konsulko.com, sjenning@redhat.com, ddstreet@ieee.org, liushixin2@huawei.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-zswap-delay-the-initializaton-of-zswap-until-the-first-enablement.patch added to mm-unstable branch Message-Id: <20220826020159.B0904C433D6@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm/zswap: delay the initializaton of zswap until the first enablement has been added to the -mm mm-unstable branch. Its filename is mm-zswap-delay-the-initializaton-of-zswap-until-the-first-enablement.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zswap-delay-the-initializaton-of-zswap-until-the-first-enablement.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Liu Shixin Subject: mm/zswap: delay the initializaton of zswap until the first enablement Date: Thu, 25 Aug 2022 22:20:36 +0800 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. Link: https://lkml.kernel.org/r/20220825142037.3214152-3-liushixin2@huawei.com Signed-off-by: Liu Shixin Cc: Dan Streetman Cc: Seth Jennings Cc: Vitaly Wool Signed-off-by: Andrew Morton --- mm/zswap.c | 48 +++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 39 insertions(+), 9 deletions(-) --- a/mm/zswap.c~mm-zswap-delay-the-initializaton-of-zswap-until-the-first-enablement +++ a/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 = ATOM /* 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 @@ error: 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 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 c 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 const struct frontswap_ops zswap_ 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(voi 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(voi /********************************* * 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; @@ -1534,6 +1555,15 @@ cache_fail: zswap_enabled = 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); _ Patches currently in -mm which might be from liushixin2@huawei.com are bootmem-remove-the-vmemmap-pages-from-kmemleak-in-put_page_bootmem.patch mm-zswap-replace-zswap_init_started-failed-with-zswap_init_state.patch mm-zswap-delay-the-initializaton-of-zswap-until-the-first-enablement.patch mm-zswap-skip-confusing-print-info.patch