From patchwork Mon Mar 29 07:55:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 412675 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 70F2EC4332B for ; Mon, 29 Mar 2021 08:18:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 39AFC61481 for ; Mon, 29 Mar 2021 08:18:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232448AbhC2ISS (ORCPT ); Mon, 29 Mar 2021 04:18:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:59086 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233216AbhC2IRJ (ORCPT ); Mon, 29 Mar 2021 04:17:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 581B261960; Mon, 29 Mar 2021 08:16:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617005807; bh=O/0q2JjobzsUmuE+dvnraPV+i669n5v5EMZTYrRvoEI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vT79fWYiAl85eInY4SPdpsrTMYL4QM123+Epl0QhQ/bBxf5A1RcIQdU7cW+fUf4je R1njm//PltpJLAbVCbq/qLkCOwwbMrMIhs3frfDsyLxqHfbEhn2Pn1Q6Lnz/IxhEOT ksh2YzCXnbSEiBagrLHP0ONwcbubTqU7N6/vRhtE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xunlei Pang , Jens Axboe , Sasha Levin Subject: [PATCH 5.10 013/221] blk-cgroup: Fix the recursive blkg rwstat Date: Mon, 29 Mar 2021 09:55:44 +0200 Message-Id: <20210329075629.620477384@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210329075629.172032742@linuxfoundation.org> References: <20210329075629.172032742@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xunlei Pang [ Upstream commit 4f44657d74873735e93a50eb25014721a66aac19 ] The current blkio.throttle.io_service_bytes_recursive doesn't work correctly. As an example, for the following blkcg hierarchy: (Made 1GB READ in test1, 512MB READ in test2) test / \ test1 test2 $ head -n 1 test/test1/blkio.throttle.io_service_bytes_recursive 8:0 Read 1073684480 $ head -n 1 test/test2/blkio.throttle.io_service_bytes_recursive 8:0 Read 537448448 $ head -n 1 test/blkio.throttle.io_service_bytes_recursive 8:0 Read 537448448 Clearly, above data of "test" reflects "test2" not "test1"+"test2". Do the correct summary in blkg_rwstat_recursive_sum(). Signed-off-by: Xunlei Pang Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-cgroup-rwstat.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/blk-cgroup-rwstat.c b/block/blk-cgroup-rwstat.c index 85d5790ac49b..3304e841df7c 100644 --- a/block/blk-cgroup-rwstat.c +++ b/block/blk-cgroup-rwstat.c @@ -109,6 +109,7 @@ void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, lockdep_assert_held(&blkg->q->queue_lock); + memset(sum, 0, sizeof(*sum)); rcu_read_lock(); blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) { struct blkg_rwstat *rwstat; @@ -122,7 +123,7 @@ void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol, rwstat = (void *)pos_blkg + off; for (i = 0; i < BLKG_RWSTAT_NR; i++) - sum->cnt[i] = blkg_rwstat_read_counter(rwstat, i); + sum->cnt[i] += blkg_rwstat_read_counter(rwstat, i); } rcu_read_unlock(); }