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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id ECAB7C001E0 for ; Wed, 26 Jul 2023 07:57:29 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=wmb9Oc63; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4R9mTN2k1vz3cG0 for ; Wed, 26 Jul 2023 17:57:28 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=wmb9Oc63; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.dev (client-ip=95.215.58.1; helo=out-1.mta1.migadu.com; envelope-from=muchun.song@linux.dev; receiver=lists.ozlabs.org) Received: from out-1.mta1.migadu.com (out-1.mta1.migadu.com [95.215.58.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4R9mTB4F0Gz30NP for ; Wed, 26 Jul 2023 17:57:16 +1000 (AEST) Content-Type: text/plain; charset=us-ascii DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1690358232; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DrTjaApThAuzzzwg/AJ38QfJI73QqK5cZWNfOYAaBzo=; b=wmb9Oc63rqgJphlqbAiUGQf+QfWRu1BB5RekgtePch6TWeTBhXF8/rZbaJe3xMLy22V28n AB61q+qfNpO4zxg1WfzVWjZzQVs0/ao+ef/zXMB6L8A11iP2pUjCxTGOuptX1W/mgnuJdh cKneJyV5E4YSzAPypp2CHjNMfrcxLhY= MIME-Version: 1.0 Subject: Re: [PATCH v2 42/47] drm/ttm: introduce pool_shrink_rwsem X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Muchun Song In-Reply-To: <20230724094354.90817-43-zhengqi.arch@bytedance.com> Date: Wed, 26 Jul 2023 15:56:40 +0800 Content-Transfer-Encoding: 7bit Message-Id: References: <20230724094354.90817-1-zhengqi.arch@bytedance.com> <20230724094354.90817-43-zhengqi.arch@bytedance.com> To: Qi Zheng X-Migadu-Flow: FLOW_OUT X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kvm@vger.kernel.org, djwong@kernel.org, Roman Gushchin , david@fromorbit.com, dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org, linux-mm@kvack.org, dm-devel@redhat.com, linux-mtd@lists.infradead.org, cel@kernel.org, x86@kernel.org, steven.price@arm.com, cluster-devel@redhat.com, xen-devel@lists.xenproject.org, linux-ext4@vger.kernel.org, "Paul E. McKenney" , linux-arm-msm@vger.kernel.org, linux-nfs@vger.kernel.org, rcu@vger.kernel.org, linux-bcache@vger.kernel.org, yujie.liu@intel.com, Vlastimil Babka , linux-raid@vger.kernel.org, Christian Brauner , tytso@mit.edu, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, Sergey Senozhatsky , netdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , linux-erofs@lists.ozlabs.org, linux-btrfs@vg er.kernel.org, tkhai@ya.ru Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" > On Jul 24, 2023, at 17:43, Qi Zheng wrote: > > Currently, the synchronize_shrinkers() is only used by TTM pool. It only > requires that no shrinkers run in parallel. > > After we use RCU+refcount method to implement the lockless slab shrink, > we can not use shrinker_rwsem or synchronize_rcu() to guarantee that all > shrinker invocations have seen an update before freeing memory. > > So we introduce a new pool_shrink_rwsem to implement a private > synchronize_shrinkers(), so as to achieve the same purpose. > > Signed-off-by: Qi Zheng Reviewed-by: Muchun Song