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 2766CC76186 for ; Wed, 24 Jul 2019 20:33:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E47802054F for ; Wed, 24 Jul 2019 20:33:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564000419; bh=S0E1UF06q68jC3495q+jItdIe+mk+gE5PVWPHXe/fOw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JgB8yhRPNSaTUklOu4kaIMl6TG70KRYaXSHufCTAn7TeU+V7uwp8mwXEH0PvmVFP5 lwMFarkxbkG86hgFpwQBw8U2svp5jpTouv22NSKhWmY9w0ZnEtyvOi5aZXn5RjNGL0 2Q3jGfRPLGXCiqV45Hc/jwruh+GZOBGQsl/2ZvR4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390741AbfGXUdi (ORCPT ); Wed, 24 Jul 2019 16:33:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:45776 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728690AbfGXT1u (ORCPT ); Wed, 24 Jul 2019 15:27:50 -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 A62C5218EA; Wed, 24 Jul 2019 19:27:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563996469; bh=S0E1UF06q68jC3495q+jItdIe+mk+gE5PVWPHXe/fOw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Jlzz/8gEPdLJZGUegcxQHh+IbFfgO9Oay771K0IM9UG8PEqqRIOCnAQkgr3cfOsh5 G4HbM028oHMbf/yNy+rmIUVFLyRPNKFEKzI6uvrole5Ze0irQo0ydARxsHJbPKe7Az a5cEQpXIxjMwTfCbZT0FW5ykh5g3ooHeSOZ0csIg= 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 5.2 106/413] blkcg, writeback: dead memcgs shouldnt contribute to writeback ownership arbitration Date: Wed, 24 Jul 2019 21:16:37 +0200 Message-Id: <20190724191742.860548714@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190724191735.096702571@linuxfoundation.org> References: <20190724191735.096702571@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 e41cbe8e81b9..9ebfb1b28430 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -715,6 +715,7 @@ 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; /* @@ -726,7 +727,12 @@ 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