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 538EDC76186 for ; Mon, 29 Jul 2019 19:26:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1E58C217F4 for ; Mon, 29 Jul 2019 19:26:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564428371; bh=LXsBI1nP7aC1KOGbkxAHfjXu8m/BrtXHKl3pF47vSZY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=L+BGBcj/jFV2uQRta/CdIZ7uqNYYFTGoT0uUKqxbnwpvk8X9id8BN8solwrz1go+k 4H+zoHYgyxlhKEzdwztXwnYhMCNCmH0SF6EslWfdG7pn2ctnRsA3tOxLsEOejYxkgS wRNT+vjxc3bieXd0CwnsDshFYizvh1e8nB9o8VQY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729102AbfG2T0K (ORCPT ); Mon, 29 Jul 2019 15:26:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:38484 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388324AbfG2T0F (ORCPT ); Mon, 29 Jul 2019 15:26:05 -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 3F5B421655; Mon, 29 Jul 2019 19:26:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564428364; bh=LXsBI1nP7aC1KOGbkxAHfjXu8m/BrtXHKl3pF47vSZY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TRGnuTwS2M2tLFXk3JcbGPcFXygIK3pieEH/CoteqpHGyfHGKj+dgwOJRGxqpM0mt ukCaoezLwPQdEHxpzJqsVF0/DW/X/HGfh5H6fPSLfH8rl0W9dicOwGby2OyH9izA9Z 3NlVWEBXTOq6/+QaHtu3DZwQ0jRt/swvQEOmULDk= 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 4.14 051/293] blkcg, writeback: dead memcgs shouldnt contribute to writeback ownership arbitration Date: Mon, 29 Jul 2019 21:19:02 +0200 Message-Id: <20190729190827.527765441@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190729190820.321094988@linuxfoundation.org> References: <20190729190820.321094988@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 4d561ee08d05..9e8fde348d61 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