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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 9B2BEC433FF for ; Fri, 2 Aug 2019 09:41:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 721E02171F for ; Fri, 2 Aug 2019 09:41:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564738906; bh=8fO4uo0G2CV+ZvGY0zTfoB37ZOd/j21ctKjBMLC1zsk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YHAZeA8nN1vpYnyb7JKv/MQipsk74VF4kFmjhN1vqfhgZwGdNBykdncTT2PA+Ronh 8fNGOxZNnNrj26W1KaAo7huP+9vSLsGrOPVQOpvwAun1+UY0LnQbEyoNT5HTJz/O/t CBP7aMgK3qzqV09OILGFfQJI997mhoDVTGo3rR8Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404888AbfHBJlo (ORCPT ); Fri, 2 Aug 2019 05:41:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:43462 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404638AbfHBJlk (ORCPT ); Fri, 2 Aug 2019 05:41:40 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9DD3A216C8; Fri, 2 Aug 2019 09:41:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564738900; bh=8fO4uo0G2CV+ZvGY0zTfoB37ZOd/j21ctKjBMLC1zsk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PBBWOMhmTNhOS9UcRKwGhSPftBk4zNI61CK+qywxhY1/8zZHxXoqAZGVrU024Q/Fx /uOhezZNkGZf9Najz7S9MIy2uRKZgfVntwLCw9eT6gpQo3mmgj3qatqVPe7z/MZv5C cmOOi4aPqgiPQK3PxPmNqpn0S9k3kdZdPwOJcnaU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tejun Heo , Jan Kara , Jens Axboe , Sasha Levin Subject: [PATCH 4.9 039/223] blkcg, writeback: dead memcgs shouldnt contribute to writeback ownership arbitration Date: Fri, 2 Aug 2019 11:34:24 +0200 Message-Id: <20190802092241.520935390@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190802092238.692035242@linuxfoundation.org> References: <20190802092238.692035242@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit 6631142229005e1b1c311a09efe9fb3cfdac8559 ] wbc_account_io() collects information on cgroup ownership of writeback pages to determine which cgroup should own the inode. Pages can stay associated with dead memcgs but we want to avoid attributing IOs to dead blkcgs as much as possible as the association is likely to be stale. However, currently, pages associated with dead memcgs contribute to the accounting delaying and/or confusing the arbitration. Fix it by ignoring pages associated with dead memcgs. Signed-off-by: Tejun Heo Cc: Jan Kara Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- fs/fs-writeback.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 8b93d4b98428..baaed9369ab4 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -721,6 +721,7 @@ void wbc_detach_inode(struct writeback_control *wbc) void wbc_account_io(struct writeback_control *wbc, struct page *page, size_t bytes) { + struct cgroup_subsys_state *css; int id; /* @@ -732,7 +733,12 @@ void wbc_account_io(struct writeback_control *wbc, struct page *page, if (!wbc->wb) return; - id = mem_cgroup_css_from_page(page)->id; + css = mem_cgroup_css_from_page(page); + /* dead cgroups shouldn't contribute to inode ownership arbitration */ + if (!(css->flags & CSS_ONLINE)) + return; + + id = css->id; if (id == wbc->wb_id) { wbc->wb_bytes += bytes; -- 2.20.1