From nobody Tue Apr 7 13:32:43 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 E6658C0502C for ; Sat, 27 Aug 2022 10:11:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233814AbiH0KLw (ORCPT ); Sat, 27 Aug 2022 06:11:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233008AbiH0KLn (ORCPT ); Sat, 27 Aug 2022 06:11:43 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7414224BD8 for ; Sat, 27 Aug 2022 03:11:41 -0700 (PDT) Received: from dggpemm500022.china.huawei.com (unknown [172.30.72.56]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4MFC7n5yV1z1N7Zp; Sat, 27 Aug 2022 18:08:05 +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; Sat, 27 Aug 2022 18:11:39 +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; Sat, 27 Aug 2022 18:11:39 +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 v3 1/5] frontswap: skip frontswap_ops init if zswap init failed. Date: Sat, 27 Aug 2022 18:45:56 +0800 Message-ID: <20220827104600.1813214-2-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220827104600.1813214-1-liushixin2@huawei.com> References: <20220827104600.1813214-1-liushixin2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) 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" If zswap initial failed or has not been initial, frontswap_ops will be NULL. In such situation, swap device would enable failed with following stack trace: Unable to handle kernel access to user memory outside uaccess routines at= virtual address 0000000000000000 Mem abort info: ESR =3D 0x0000000096000004 EC =3D 0x25: DABT (current EL), IL =3D 32 bits SET =3D 0, FnV =3D 0 EA =3D 0, S1PTW =3D 0 FSC =3D 0x04: level 0 translation fault Data abort info: ISV =3D 0, ISS =3D 0x00000004 CM =3D 0, WnR =3D 0 user pgtable: 4k pages, 48-bit VAs, pgdp=3D00000020a4fab000 [0000000000000000] pgd=3D0000000000000000, p4d=3D0000000000000000 Internal error: Oops: 96000004 [#1] SMP Modules linked in: zram fsl_dpaa2_eth pcs_lynx phylink ahci_qoriq crct10d= if_ce ghash_ce sbsa_gwdt fsl_mc_dpio nvme lm90 nvme_core at803x xhci_plat_h= cd rtc_fsl_ftm_alarm xgmac_mdio ahci_platform i2c_imx ip6_tables ip_tables = fuse Unloaded tainted modules: cppc_cpufreq():1 CPU: 10 PID: 761 Comm: swapon Not tainted 6.0.0-rc2-00454-g22100432cf14 #1 Hardware name: SolidRun Ltd. SolidRun CEX7 Platform, BIOS EDK II Jun 21 2= 022 pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=3D--) pc : frontswap_init+0x38/0x60 lr : __do_sys_swapon+0x8a8/0x9f4 sp : ffff80000969bcf0 x29: ffff80000969bcf0 x28: ffff37bee0d8fc00 x27: ffff80000a7f5000 x26: fffffcdefb971e80 x25: ffffaba797453b90 x24: 0000000000000064 x23: ffff37c1f209d1a8 x22: ffff37bee880e000 x21: ffffaba797748560 x20: ffff37bee0d8fce4 x19: ffffaba797748488 x18: 0000000000000014 x17: 0000000030ec029a x16: ffffaba795a479b0 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000030 x12: 0000000000000001 x11: ffff37c63c0aba18 x10: 0000000000000000 x9 : ffffaba7956b8c88 x8 : ffff80000969bcd0 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000001 x4 : 0000000000000000 x3 : ffffaba79730f000 x2 : ffff37bee0d8fc00 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: frontswap_init+0x38/0x60 __do_sys_swapon+0x8a8/0x9f4 __arm64_sys_swapon+0x28/0x3c invoke_syscall+0x78/0x100 el0_svc_common.constprop.0+0xd4/0xf4 do_el0_svc+0x38/0x4c el0_svc+0x34/0x10c el0t_64_sync_handler+0x11c/0x150 el0t_64_sync+0x190/0x194 Code: d000e283 910003fd f9006c41 f946d461 (f9400021) ---[ end trace 0000000000000000 ]--- Reported-by: Nathan Chancellor Signed-off-by: Liu Shixin --- mm/frontswap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/frontswap.c b/mm/frontswap.c index 1a97610308cb..620f95af81dd 100644 --- a/mm/frontswap.c +++ b/mm/frontswap.c @@ -125,7 +125,8 @@ void frontswap_init(unsigned type, unsigned long *map) * p->frontswap set to something valid to work properly. */ frontswap_map_set(sis, map); - frontswap_ops->init(type); + if (frontswap_ops) + frontswap_ops->init(type); } =20 static bool __frontswap_test(struct swap_info_struct *sis, --=20 2.25.1 From nobody Tue Apr 7 13:32:43 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 CB2EAECAAD2 for ; Sat, 27 Aug 2022 10:12:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234348AbiH0KMN (ORCPT ); Sat, 27 Aug 2022 06:12:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235565AbiH0KMB (ORCPT ); Sat, 27 Aug 2022 06:12:01 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 344472714C for ; Sat, 27 Aug 2022 03:11:56 -0700 (PDT) Received: from dggpemm500023.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4MFC7B0rL5zYcvD; Sat, 27 Aug 2022 18:07:34 +0800 (CST) Received: from dggpemm100009.china.huawei.com (7.185.36.113) by dggpemm500023.china.huawei.com (7.185.36.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Sat, 27 Aug 2022 18:11:40 +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; Sat, 27 Aug 2022 18:11:40 +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 v3 2/5] frontswap: invoke ops->init for online swap device in frontswap_register_ops Date: Sat, 27 Aug 2022 18:45:57 +0800 Message-ID: <20220827104600.1813214-3-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220827104600.1813214-1-liushixin2@huawei.com> References: <20220827104600.1813214-1-liushixin2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) 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" Since we are supported to delay zswap initializaton, we need to invoke ops->init for the swap device which is already online when register backend. This patch is a revert of f328c1d16e4c ("frontswap: simplify frontswap_regi= ster_ops") and 633423a09cb5 ("mm: mark swap_lock and swap_active_head static") Signed-off-by: Liu Shixin --- include/linux/swapfile.h | 2 ++ mm/frontswap.c | 47 ++++++++++++++++++++++++++++++++++++++++ mm/swapfile.c | 4 ++-- 3 files changed, 51 insertions(+), 2 deletions(-) diff --git a/include/linux/swapfile.h b/include/linux/swapfile.h index 2fbcc9afd814..75fc069594a5 100644 --- a/include/linux/swapfile.h +++ b/include/linux/swapfile.h @@ -6,6 +6,8 @@ * these were static in swapfile.c but frontswap.c needs them and we don't * want to expose them to the dozens of source files that include swap.h */ +extern spinlock_t swap_lock; +extern struct plist_head swap_active_head; extern struct swap_info_struct *swap_info[]; extern unsigned long generic_max_swapfile_size(void); /* Maximum swapfile size supported for the arch (not inclusive). */ diff --git a/mm/frontswap.c b/mm/frontswap.c index 620f95af81dd..449e6f499b88 100644 --- a/mm/frontswap.c +++ b/mm/frontswap.c @@ -96,11 +96,58 @@ static inline void inc_frontswap_invalidates(void) { } */ int frontswap_register_ops(const struct frontswap_ops *ops) { + DECLARE_BITMAP(a, MAX_SWAPFILES); + DECLARE_BITMAP(b, MAX_SWAPFILES); + struct swap_info_struct *si; + unsigned int i; + if (frontswap_ops) return -EINVAL; =20 + bitmap_zero(a, MAX_SWAPFILES); + bitmap_zero(b, MAX_SWAPFILES); + + spin_lock(&swap_lock); + plist_for_each_entry(si, &swap_active_head, list) { + if (!WARN_ON(!si->frontswap_map)) + __set_bit(si->type, a); + } + spin_unlock(&swap_lock); + + /* the new ops needs to know the currently active swap devices */ + for_each_set_bit(i, a, MAX_SWAPFILES) { + pr_err("init frontswap_ops\n"); + ops->init(i); + } + frontswap_ops =3D ops; static_branch_inc(&frontswap_enabled_key); + + spin_lock(&swap_lock); + plist_for_each_entry(si, &swap_active_head, list) { + if (si->frontswap_map) + __set_bit(si->type, b); + } + spin_unlock(&swap_lock); + + /* + * On the very unlikely chance that a swap device was added or + * removed between setting the "a" list bits and the ops init + * calls, we re-check and do init or invalidate for any changed + * bits. + */ + if (unlikely(!bitmap_equal(a, b, MAX_SWAPFILES))) { + for (i =3D 0; i < MAX_SWAPFILES; i++) { + if (!test_bit(i, a) && test_bit(i, b)) { + pr_err("init frontswap_ops re\n"); + ops->init(i); + } else if (test_bit(i, a) && !test_bit(i, b)) { + pr_err("inval frontswap_ops re\n"); + ops->invalidate_area(i); + } + } + } + return 0; } =20 diff --git a/mm/swapfile.c b/mm/swapfile.c index 469d9af86be2..d383b282f269 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -51,7 +51,7 @@ static bool swap_count_continued(struct swap_info_struct = *, pgoff_t, unsigned char); static void free_swap_count_continuations(struct swap_info_struct *); =20 -static DEFINE_SPINLOCK(swap_lock); +DEFINE_SPINLOCK(swap_lock); static unsigned int nr_swapfiles; atomic_long_t nr_swap_pages; /* @@ -77,7 +77,7 @@ static const char Unused_offset[] =3D "Unused swap offset= entry "; * all active swap_info_structs * protected with swap_lock, and ordered by priority. */ -static PLIST_HEAD(swap_active_head); +PLIST_HEAD(swap_active_head); =20 /* * all available (active, not full) swap_info_structs --=20 2.25.1 From nobody Tue Apr 7 13:32:43 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 88DB5C0502C for ; Sat, 27 Aug 2022 10:12:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233937AbiH0KL7 (ORCPT ); Sat, 27 Aug 2022 06:11:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233463AbiH0KLp (ORCPT ); Sat, 27 Aug 2022 06:11:45 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AE1A124F01 for ; Sat, 27 Aug 2022 03:11:43 -0700 (PDT) Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.57]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4MFC9y5qdZzGpGr; Sat, 27 Aug 2022 18:09:58 +0800 (CST) Received: from dggpemm100009.china.huawei.com (7.185.36.113) by dggpemm500024.china.huawei.com (7.185.36.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Sat, 27 Aug 2022 18:11:41 +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; Sat, 27 Aug 2022 18:11:41 +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 v3 3/5] mm/zswap: replace zswap_init_{started/failed} with zswap_init_state Date: Sat, 27 Aug 2022 18:45:58 +0800 Message-ID: <20220827104600.1813214-4-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220827104600.1813214-1-liushixin2@huawei.com> References: <20220827104600.1813214-1-liushixin2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) 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 Reviewed-by: Vitaly Wool --- 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 13:32:43 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 A3887ECAAD2 for ; Sat, 27 Aug 2022 10:12:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237071AbiH0KMK (ORCPT ); Sat, 27 Aug 2022 06:12:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233533AbiH0KLs (ORCPT ); Sat, 27 Aug 2022 06:11:48 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93BA624F19 for ; Sat, 27 Aug 2022 03:11:44 -0700 (PDT) Received: from dggpemm500021.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MFC7r4rZFzkWKd; Sat, 27 Aug 2022 18:08:08 +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; Sat, 27 Aug 2022 18:11:42 +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; Sat, 27 Aug 2022 18:11:42 +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 v3 4/5] mm/zswap: delay the initializaton of zswap until the first enablement Date: Sat, 27 Aug 2022 18:45:59 +0800 Message-ID: <20220827104600.1813214-5-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220827104600.1813214-1-liushixin2@huawei.com> References: <20220827104600.1813214-1-liushixin2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) 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 Reviewed-by: Vitaly Wool --- mm/zswap.c | 50 ++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 40 insertions(+), 10 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index 84e38300f571..4c476c463035 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; @@ -1534,8 +1555,17 @@ static int __init init_zswap(void) zswap_enabled =3D 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); =20 MODULE_LICENSE("GPL"); MODULE_AUTHOR("Seth Jennings "); --=20 2.25.1 From nobody Tue Apr 7 13:32:43 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 EA6D0ECAAD2 for ; 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Sat, 27 Aug 2022 18:11:43 +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 v3 5/5] mm/zswap: skip confusing print info Date: Sat, 27 Aug 2022 18:46:00 +0800 Message-ID: <20220827104600.1813214-6-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220827104600.1813214-1-liushixin2@huawei.com> References: <20220827104600.1813214-1-liushixin2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) 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 4c476c463035..ef7463550e49 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