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,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 7D1CFC433E6 for ; Thu, 21 Jan 2021 23:06:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0530E2389F for ; Thu, 21 Jan 2021 23:06:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0530E2389F 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 4D6B26B000E; Thu, 21 Jan 2021 18:06:51 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4AF6F6B0010; Thu, 21 Jan 2021 18:06:51 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 28B916B0012; Thu, 21 Jan 2021 18:06:51 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0149.hostedemail.com [216.40.44.149]) by kanga.kvack.org (Postfix) with ESMTP id 135766B000E for ; Thu, 21 Jan 2021 18:06:51 -0500 (EST) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id D08C46125 for ; Thu, 21 Jan 2021 23:06:50 +0000 (UTC) X-FDA: 77731318980.07.wheel87_5e1297127567 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin07.hostedemail.com (Postfix) with ESMTP id ABFA41808BB22 for ; Thu, 21 Jan 2021 23:06:50 +0000 (UTC) X-HE-Tag: wheel87_5e1297127567 X-Filterd-Recvd-Size: 7067 Received: from mail-pf1-f175.google.com (mail-pf1-f175.google.com [209.85.210.175]) by imf08.hostedemail.com (Postfix) with ESMTP for ; Thu, 21 Jan 2021 23:06:50 +0000 (UTC) Received: by mail-pf1-f175.google.com with SMTP id w14so2472470pfi.2 for ; Thu, 21 Jan 2021 15:06:50 -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=nnB8h59OPJ5JvB/lyk5EwUCcxRhMfxfME1UgDyDGoQ4=; b=QCywdeQAJFYgBjkq16w9Nwd1NEJ6ZQaVs0eqqZSRHYkuLblNXGnvzIhx1G+5k3GrR0 CL7EEnT4+9GOVXUQsbTzqzeo2uRy2ogXPFp7fH+Q5ad3kp3n/mZmGHGvG8TDaduz/5fZ yhMubrMH+qn+GOnwuajNYd446QuDY7qy9ytv401sIGjE4QYo+B5fAEULnwDCD5A+SBkN LqMTcA6zvOIof+MLYmcXm8IfwjVcmSz/OSPTh+jnhbBzO+G4zIIMhZAO/Bh6Tc9epdLU Bcn6sqbHgRLUO8pdrHQh8/d1eh8rfkNutkMz7dmtkQhwJm/irdm7xOlBGyVLOtL6MtOw i4pg== 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=nnB8h59OPJ5JvB/lyk5EwUCcxRhMfxfME1UgDyDGoQ4=; b=RW/Vvw+NFqk6+K+uZMACKcA5xrF8+2EBDxuO7602FEL028eyyMje3K6xesmJLCmw8j cKYqMpPgX52lVRGD3Gs7LhabizDOwa6bY08EN8si0PTKBl3jNdWn4O/hFkpACkdvvAoQ z6OqiukA+fDE3RS1bI7NMmGgOBtLuodwxJgAifaaHaFGRegNogSeaXE4UF4TmBx4jmcW CUYtaEnBqLG0Nz0tfTO78lPAqBwYfLGiGnUC5xdLor+Mic8ksscHGoVrkdSF4VSW+kkU 5EGRnA7xqMADwqFd11AZmKKU3Qxjkv5Wjckzwa1rMAitivOYtaIke4iBkSrjdYZvwCSd RB1Q== X-Gm-Message-State: AOAM531P7PuqupdMNiz0//lGVfvnOB12X3o2D3nMluUy54kihbc5uj1v qhF1sdoigzPWJ9Kl6Z+pFhY= X-Google-Smtp-Source: ABdhPJzSxoYXXWg9qJp6Wsca6bMsr1MdN+qYTw1gM5auopTSgB/O1V2pm1yyZwbcayuB+/p//fu8Pw== X-Received: by 2002:a63:4923:: with SMTP id w35mr1615014pga.404.1611270409472; Thu, 21 Jan 2021 15:06:49 -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 y16sm6722921pfb.83.2021.01.21.15.06.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 21 Jan 2021 15:06:48 -0800 (PST) From: Yang Shi To: guro@fb.com, ktkhai@virtuozzo.com, 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: [v4 PATCH 06/11] mm: vmscan: use a new flag to indicate shrinker is registered Date: Thu, 21 Jan 2021 15:06:16 -0800 Message-Id: <20210121230621.654304-7-shy828301@gmail.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210121230621.654304-1-shy828301@gmail.com> References: <20210121230621.654304-1-shy828301@gmail.com> MIME-Version: 1.0 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. Signed-off-by: Yang Shi --- include/linux/shrinker.h | 7 ++++--- mm/vmscan.c | 27 +++++++++------------------ 2 files changed, 13 insertions(+), 21 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 dcb7f2913ace..018e1beb24c9 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -308,19 +308,6 @@ 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) @@ -329,7 +316,7 @@ 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, NULL, 0, 0, GFP_KERNEL); if (id < 0) goto unlock; =20 @@ -496,6 +483,7 @@ void register_shrinker_prepared(struct shrinker *shri= nker) if (shrinker->flags & SHRINKER_MEMCG_AWARE) idr_replace(&shrinker_idr, shrinker, shrinker->id); #endif + shrinker->flags |=3D SHRINKER_REGISTERED; up_write(&shrinker_rwsem); } =20 @@ -515,13 +503,16 @@ 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; up_write(&shrinker_rwsem); + + if (shrinker->flags & SHRINKER_MEMCG_AWARE) + unregister_memcg_shrinker(shrinker); kfree(shrinker->nr_deferred); shrinker->nr_deferred =3D NULL; } @@ -687,7 +678,7 @@ 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