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 X-Spam-Level: X-Spam-Status: No, score=-13.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA308C433DB for ; Wed, 10 Mar 2021 17:46:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 808D764F1D for ; Wed, 10 Mar 2021 17:46:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 808D764F1D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 239AC8D01E7; Wed, 10 Mar 2021 12:46:33 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 20FF08D01D5; Wed, 10 Mar 2021 12:46:33 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0FFEB8D01E7; Wed, 10 Mar 2021 12:46:33 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0034.hostedemail.com [216.40.44.34]) by kanga.kvack.org (Postfix) with ESMTP id EB26E8D01D5 for ; Wed, 10 Mar 2021 12:46:32 -0500 (EST) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 9B8728249980 for ; Wed, 10 Mar 2021 17:46:32 +0000 (UTC) X-FDA: 77904694224.24.1C46E83 Received: from mail-pl1-f177.google.com (mail-pl1-f177.google.com [209.85.214.177]) by imf03.hostedemail.com (Postfix) with ESMTP id D53B5C001C5F for ; Wed, 10 Mar 2021 17:46:29 +0000 (UTC) Received: by mail-pl1-f177.google.com with SMTP id a24so8826512plm.11 for ; Wed, 10 Mar 2021 09:46:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=9fzXcQw4lBeUc4+bt/8wnQKsoR0U89o0QoJXEyYgW5c=; b=FB2Yz9RmCu+ccD2Dwwe/AYp1avMlu8LfTcD9I/7Gkv1HQtjz9zXwn8q9snSDKkBaOR Zmt5nDGnCdt+LLNUHbIjOmgX2dSrfPgvj0KqfBCk/9GvlYT980VQrjV8xpu7fgpMyK6f nXvGEhzI6pwyU1kepjOtJ1wIYlzLxogcub7t4cOLohSg4FQfhhnf1WSnMAhk05Q0IqAl p4SekSkSINOsiM7LvObXt/kMivy57B5UvPhushop8U+a7PlgNjOX5FrrZfmHAdl0SHYr o91epyagM874nS7cOdKfFA9NGDRNS6pTzCNG0mbvAvPOBMgW+L0nuFK97z9Z41i6MKK1 PacA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=9fzXcQw4lBeUc4+bt/8wnQKsoR0U89o0QoJXEyYgW5c=; b=ftQNt9ceJncbLAVPa2cuBu4h/LrluR+9yaKV66Ba48afG+5FFs84D68DqKJCZz1WJZ cnZCeKaQbWV+AY6DIUuFYSnl+X5ZDLN+wsqSWhmbV+YGYURM3kDWIXEUPkOKGGMl4WTU CxoA63XjHJEmagiruTBxGTKQlzLmtWB4pBSFc44fkODTG9GpRsFrhQ155YniK35Bts5X 5kKAkk/5DFD0gk32YDjkPq5AyaDIyUAkj21ClT2MI3L9NFTFGHIT6TBYHpEA7scx6tf1 PxdB+KYP0Fyxh0fHqVis84xrjcirW0ip5xw+J9Hf2WE3g8QhbUSkOBkPPDMemhLde+ty 4ihA== X-Gm-Message-State: AOAM530/30cVQfzv8tHlBkgGwZiRcxvxbsUQu25SV9jWpNalyUJrk7+z hYeyK00qZEiNdDeHyaBGyq0= X-Google-Smtp-Source: ABdhPJz8789kCVyakl8XlWuYd//XMEoDUSopV1h4rWINLev2b+o9UbsIsldLfTnNXgAxWJQtsoMRow== X-Received: by 2002:a17:90a:bf04:: with SMTP id c4mr4610626pjs.170.1615398391251; Wed, 10 Mar 2021 09:46:31 -0800 (PST) Received: from localhost.localdomain (c-73-93-239-127.hsd1.ca.comcast.net. [73.93.239.127]) by smtp.gmail.com with ESMTPSA id d6sm145804pfq.109.2021.03.10.09.46.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Mar 2021 09:46:30 -0800 (PST) From: Yang Shi To: guro@fb.com, ktkhai@virtuozzo.com, vbabka@suse.cz, shakeelb@google.com, david@fromorbit.com, hannes@cmpxchg.org, mhocko@suse.com, akpm@linux-foundation.org Cc: shy828301@gmail.com, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [v9 PATCH 08/13] mm: vmscan: use a new flag to indicate shrinker is registered Date: Wed, 10 Mar 2021 09:45:58 -0800 Message-Id: <20210310174603.5093-9-shy828301@gmail.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210310174603.5093-1-shy828301@gmail.com> References: <20210310174603.5093-1-shy828301@gmail.com> MIME-Version: 1.0 X-Stat-Signature: 7s3s6w5cxfpcmbottg8ngqxianyczg75 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: D53B5C001C5F Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf03; identity=mailfrom; envelope-from=""; helo=mail-pl1-f177.google.com; client-ip=209.85.214.177 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1615398389-15619 Content-Transfer-Encoding: quoted-printable 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: Currently registered shrinker is indicated by non-NULL shrinker->nr_defer= red. This approach is fine with nr_deferred at the shrinker level, but the fol= lowing patches will move MEMCG_AWARE shrinkers' nr_deferred to memcg level, so t= heir shrinker->nr_deferred would always be NULL. This would prevent the shrin= kers from unregistering correctly. Remove SHRINKER_REGISTERING since we could check if shrinker is registere= d successfully by the new flag. Acked-by: Kirill Tkhai Acked-by: Vlastimil Babka Acked-by: Roman Gushchin Reviewed-by: Shakeel Butt Signed-off-by: Yang Shi --- include/linux/shrinker.h | 7 ++++--- mm/vmscan.c | 40 +++++++++++++++------------------------- 2 files changed, 19 insertions(+), 28 deletions(-) diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h index 0f80123650e2..1eac79ce57d4 100644 --- a/include/linux/shrinker.h +++ b/include/linux/shrinker.h @@ -79,13 +79,14 @@ struct shrinker { #define DEFAULT_SEEKS 2 /* A good number if you don't know better. */ =20 /* Flags */ -#define SHRINKER_NUMA_AWARE (1 << 0) -#define SHRINKER_MEMCG_AWARE (1 << 1) +#define SHRINKER_REGISTERED (1 << 0) +#define SHRINKER_NUMA_AWARE (1 << 1) +#define SHRINKER_MEMCG_AWARE (1 << 2) /* * It just makes sense when the shrinker is also MEMCG_AWARE for now, * non-MEMCG_AWARE shrinker should not have this flag set. */ -#define SHRINKER_NONSLAB (1 << 2) +#define SHRINKER_NONSLAB (1 << 3) =20 extern int prealloc_shrinker(struct shrinker *shrinker); extern void register_shrinker_prepared(struct shrinker *shrinker); diff --git a/mm/vmscan.c b/mm/vmscan.c index c0d04f242917..d0876970601e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -314,19 +314,6 @@ void set_shrinker_bit(struct mem_cgroup *memcg, int = nid, int shrinker_id) } } =20 -/* - * We allow subsystems to populate their shrinker-related - * LRU lists before register_shrinker_prepared() is called - * for the shrinker, since we don't want to impose - * restrictions on their internal registration order. - * In this case shrink_slab_memcg() may find corresponding - * bit is set in the shrinkers map. - * - * This value is used by the function to detect registering - * shrinkers and to skip do_shrink_slab() calls for them. - */ -#define SHRINKER_REGISTERING ((struct shrinker *)~0UL) - static DEFINE_IDR(shrinker_idr); =20 static int prealloc_memcg_shrinker(struct shrinker *shrinker) @@ -335,7 +322,7 @@ static int prealloc_memcg_shrinker(struct shrinker *s= hrinker) =20 down_write(&shrinker_rwsem); /* This may call shrinker, so it must use down_read_trylock() */ - id =3D idr_alloc(&shrinker_idr, SHRINKER_REGISTERING, 0, 0, GFP_KERNEL)= ; + id =3D idr_alloc(&shrinker_idr, shrinker, 0, 0, GFP_KERNEL); if (id < 0) goto unlock; =20 @@ -358,9 +345,9 @@ static void unregister_memcg_shrinker(struct shrinker= *shrinker) =20 BUG_ON(id < 0); =20 - down_write(&shrinker_rwsem); + lockdep_assert_held(&shrinker_rwsem); + idr_remove(&shrinker_idr, id); - up_write(&shrinker_rwsem); } =20 static bool cgroup_reclaim(struct scan_control *sc) @@ -488,8 +475,11 @@ void free_prealloced_shrinker(struct shrinker *shrin= ker) if (!shrinker->nr_deferred) return; =20 - if (shrinker->flags & SHRINKER_MEMCG_AWARE) + if (shrinker->flags & SHRINKER_MEMCG_AWARE) { + down_write(&shrinker_rwsem); unregister_memcg_shrinker(shrinker); + up_write(&shrinker_rwsem); + } =20 kfree(shrinker->nr_deferred); shrinker->nr_deferred =3D NULL; @@ -499,10 +489,7 @@ void register_shrinker_prepared(struct shrinker *shr= inker) { down_write(&shrinker_rwsem); list_add_tail(&shrinker->list, &shrinker_list); -#ifdef CONFIG_MEMCG - if (shrinker->flags & SHRINKER_MEMCG_AWARE) - idr_replace(&shrinker_idr, shrinker, shrinker->id); -#endif + shrinker->flags |=3D SHRINKER_REGISTERED; up_write(&shrinker_rwsem); } =20 @@ -522,13 +509,16 @@ EXPORT_SYMBOL(register_shrinker); */ void unregister_shrinker(struct shrinker *shrinker) { - if (!shrinker->nr_deferred) + if (!(shrinker->flags & SHRINKER_REGISTERED)) return; - if (shrinker->flags & SHRINKER_MEMCG_AWARE) - unregister_memcg_shrinker(shrinker); + down_write(&shrinker_rwsem); list_del(&shrinker->list); + shrinker->flags &=3D ~SHRINKER_REGISTERED; + if (shrinker->flags & SHRINKER_MEMCG_AWARE) + unregister_memcg_shrinker(shrinker); up_write(&shrinker_rwsem); + kfree(shrinker->nr_deferred); shrinker->nr_deferred =3D NULL; } @@ -693,7 +683,7 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask= , int nid, struct shrinker *shrinker; =20 shrinker =3D idr_find(&shrinker_idr, i); - if (unlikely(!shrinker || shrinker =3D=3D SHRINKER_REGISTERING)) { + if (unlikely(!shrinker || !(shrinker->flags & SHRINKER_REGISTERED))) { if (!shrinker) clear_bit(i, info->map); continue; --=20 2.26.2