From patchwork Tue Nov 17 13:02:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 1401538 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.linux.it (client-ip=213.254.12.146; helo=picard.linux.it; envelope-from=ltp-bounces+incoming=patchwork.ozlabs.org@lists.linux.it; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=yyLFQK0T; dkim-atps=neutral Received: from picard.linux.it (picard.linux.it [213.254.12.146]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4Cb6K16dkczB3vj for ; 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c=relaxed/simple; d=kernel.org; s=default; t=1605619846; bh=6+JiWbjiMpRAJIAOZZHvDe3aPZI7EpxydlFtgIX8Fxc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yyLFQK0TK5EOP1ftX53QjoIcHsZZfT3qbx3X/n+jhyzpNaBifV0YEPAwvru/6poxV UGoBPKxmgz0HHliJV5IeRNUwVlJH7NX0ZFpO1T2TsC9PYE4wG8V6etk7EiZ8GPBm78 L3u+upDejeUG8TzJaPWb3U7Oe1+QVUCnU6UrkgQY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Date: Tue, 17 Nov 2020 14:02:23 +0100 Message-Id: <20201117122139.098694275@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201117122138.925150709@linuxfoundation.org> References: <20201117122138.925150709@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.102.4 at in-5.smtp.seeweb.it X-Virus-Status: Clean X-Spam-Status: No, score=0.1 required=7.0 tests=DKIM_SIGNED,DKIM_VALID, SPF_HELO_NONE,SPF_PASS autolearn=disabled version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on in-5.smtp.seeweb.it Subject: [LTP] [PATCH 5.9 003/255] mm: memcg: link page counters to root if use_hierarchy is false X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sasha Levin , Greg Kroah-Hartman , stable@vger.kernel.org, Michal Hocko , Shakeel Butt , Richard Palethorpe , Johannes Weiner , =?utf-8?q?Michal_Koutn=C3=BD?= , Andrew Morton , Linus Torvalds , Roman Gushchin , ltp@lists.linux.it Errors-To: ltp-bounces+incoming=patchwork.ozlabs.org@lists.linux.it Sender: "ltp" From: Roman Gushchin [ Upstream commit 8de15e920dc85d1705ab9c202c95d56845bc2d48 ] Richard reported a warning which can be reproduced by running the LTP madvise6 test (cgroup v1 in the non-hierarchical mode should be used): WARNING: CPU: 0 PID: 12 at mm/page_counter.c:57 page_counter_uncharge (mm/page_counter.c:57 mm/page_counter.c:50 mm/page_counter.c:156) Modules linked in: CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.9.0-rc7-22-default #77 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-48-gd9c812d-rebuilt.opensuse.org 04/01/2014 Workqueue: events drain_local_stock RIP: 0010:page_counter_uncharge (mm/page_counter.c:57 mm/page_counter.c:50 mm/page_counter.c:156) Call Trace: __memcg_kmem_uncharge (mm/memcontrol.c:3022) drain_obj_stock (./include/linux/rcupdate.h:689 mm/memcontrol.c:3114) drain_local_stock (mm/memcontrol.c:2255) process_one_work (./arch/x86/include/asm/jump_label.h:25 ./include/linux/jump_label.h:200 ./include/trace/events/workqueue.h:108 kernel/workqueue.c:2274) worker_thread (./include/linux/list.h:282 kernel/workqueue.c:2416) kthread (kernel/kthread.c:292) ret_from_fork (arch/x86/entry/entry_64.S:300) The problem occurs because in the non-hierarchical mode non-root page counters are not linked to root page counters, so the charge is not propagated to the root memory cgroup. After the removal of the original memory cgroup and reparenting of the object cgroup, the root cgroup might be uncharged by draining a objcg stock, for example. It leads to an eventual underflow of the charge and triggers a warning. Fix it by linking all page counters to corresponding root page counters in the non-hierarchical mode. Please note, that in the non-hierarchical mode all objcgs are always reparented to the root memory cgroup, even if the hierarchy has more than 1 level. This patch doesn't change it. The patch also doesn't affect how the hierarchical mode is working, which is the only sane and truly supported mode now. Thanks to Richard for reporting, debugging and providing an alternative version of the fix! Fixes: bf4f059954dc ("mm: memcg/slab: obj_cgroup API") Reported-by: Signed-off-by: Roman Gushchin Signed-off-by: Andrew Morton Reviewed-by: Shakeel Butt Reviewed-by: Michal Koutný Acked-by: Johannes Weiner Cc: Michal Hocko Cc: Link: https://lkml.kernel.org/r/20201026231326.3212225-1-guro@fb.com Debugged-by: Richard Palethorpe Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/memcontrol.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 9eefdb9cc2303..de51787831728 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5298,7 +5298,13 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) memcg->swappiness = mem_cgroup_swappiness(parent); memcg->oom_kill_disable = parent->oom_kill_disable; } - if (parent && parent->use_hierarchy) { + if (!parent) { + page_counter_init(&memcg->memory, NULL); + page_counter_init(&memcg->swap, NULL); + page_counter_init(&memcg->memsw, NULL); + page_counter_init(&memcg->kmem, NULL); + page_counter_init(&memcg->tcpmem, NULL); + } else if (parent->use_hierarchy) { memcg->use_hierarchy = true; page_counter_init(&memcg->memory, &parent->memory); page_counter_init(&memcg->swap, &parent->swap); @@ -5306,11 +5312,11 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) page_counter_init(&memcg->kmem, &parent->kmem); page_counter_init(&memcg->tcpmem, &parent->tcpmem); } else { - page_counter_init(&memcg->memory, NULL); - page_counter_init(&memcg->swap, NULL); - page_counter_init(&memcg->memsw, NULL); - page_counter_init(&memcg->kmem, NULL); - page_counter_init(&memcg->tcpmem, NULL); + page_counter_init(&memcg->memory, &root_mem_cgroup->memory); + page_counter_init(&memcg->swap, &root_mem_cgroup->swap); + page_counter_init(&memcg->memsw, &root_mem_cgroup->memsw); + page_counter_init(&memcg->kmem, &root_mem_cgroup->kmem); + page_counter_init(&memcg->tcpmem, &root_mem_cgroup->tcpmem); /* * Deeper hierachy with use_hierarchy == false doesn't make * much sense so let cgroup subsystem know about this From patchwork Tue Nov 17 13:05:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 1401540 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.linux.it (client-ip=213.254.12.146; helo=picard.linux.it; envelope-from=ltp-bounces+incoming=patchwork.ozlabs.org@lists.linux.it; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=Co/jX+Fp; dkim-atps=neutral Received: from picard.linux.it (picard.linux.it [213.254.12.146]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4Cb6W36rWsz9sWw for ; Wed, 18 Nov 2020 00:39:43 +1100 (AEDT) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id 585503C5A1F for ; Tue, 17 Nov 2020 14:39:41 +0100 (CET) X-Original-To: ltp@lists.linux.it Delivered-To: ltp@picard.linux.it Received: from in-2.smtp.seeweb.it (in-2.smtp.seeweb.it [217.194.8.2]) by picard.linux.it (Postfix) with ESMTP id 2FF1F3C25DB for ; Tue, 17 Nov 2020 14:39:40 +0100 (CET) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by in-2.smtp.seeweb.it (Postfix) with ESMTPS id 9B5C560123C for ; Tue, 17 Nov 2020 14:39:39 +0100 (CET) Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 ECB4C2468D; Tue, 17 Nov 2020 13:39:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605620376; bh=BJxXwPFVPC2oTDeqVeV3w+TrQZ3GLWMOJ91YNGurQC4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Co/jX+Fp8UqU42uprUhBHb0Ng77+Vw8yFRDzUg7iB5UBcewduS/jxIoYsRdVwgLSZ DpDsGSfLVWkkTOZ8lnml50MLJ3THlmnAFh2J5Heyve8EEsxssR+ZisVjMMNUdrWG35 JAWzgGDrLD8yIfor8xzzsFCUNKxvTVSqHn51brcM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Date: Tue, 17 Nov 2020 14:05:38 +0100 Message-Id: <20201117122148.567147400@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201117122138.925150709@linuxfoundation.org> References: <20201117122138.925150709@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.102.4 at in-2.smtp.seeweb.it X-Virus-Status: Clean X-Spam-Status: No, score=0.1 required=7.0 tests=DKIM_SIGNED,DKIM_VALID, SPF_HELO_NONE,SPF_PASS autolearn=disabled version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on in-2.smtp.seeweb.it Subject: [LTP] [PATCH 5.9 198/255] loop: Fix occasional uevent drop X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jens Axboe , Greg Kroah-Hartman , stable@vger.kernel.org, Christoph Hellwig , ltp@lists.linux.it Errors-To: ltp-bounces+incoming=patchwork.ozlabs.org@lists.linux.it Sender: "ltp" From: Petr Vorel commit c01a21b77722db0474bbcc4eafc8c4e0d8fed6d8 upstream. Commit 716ad0986cbd ("loop: Switch to set_capacity_revalidate_and_notify") causes an occasional drop of loop device uevent, which are no longer triggered in loop_set_size() but in a different part of code. Bug is reproducible with LTP test uevent01 [1]: i=0; while true; do i=$((i+1)); echo "== $i ==" lsmod |grep -q loop && rmmod -f loop ./uevent01 || break done Put back triggering through code called in loop_set_size(). Fix required to add yet another parameter to set_capacity_revalidate_and_notify(). [1] https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/uevents/uevent01.c [hch: rebased on a different change to the prototype of set_capacity_revalidate_and_notify] Cc: stable@vger.kernel.org # v5.9 Fixes: 716ad0986cbd ("loop: Switch to set_capacity_revalidate_and_notify") Reported-by: Signed-off-by: Petr Vorel Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/block/loop.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -255,7 +255,8 @@ static void loop_set_size(struct loop_de bd_set_size(bdev, size << SECTOR_SHIFT); - set_capacity_revalidate_and_notify(lo->lo_disk, size, false); + if (!set_capacity_revalidate_and_notify(lo->lo_disk, size, false)) + kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); } static inline int