From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D695D3A4F26 for ; Fri, 1 May 2026 12:35:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777638949; cv=none; b=dyIxQ4fuj1eBsvWAXeulVSAGu/POEcGkW7ih+gMZGu0XPoSsmLWi5LyGwgnH67cc2hFpPDCEbtDstb9/1AOGCfBPMFsIehkTJP8+piI69xcGOmU84jDno1n6CNdPQFGWlk/dC1YLJXOhrOlDh0O9LJqIxZXmXhXY4/Jc47GCVVg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777638949; c=relaxed/simple; bh=xvSVvF9WrgDkC4Y95og+EY5X2F5L2VauJZ6etEhWdc4=; h=Date:To:From:Subject:Message-Id; b=E1yuvGiARzQjEXl6C42LG493WWpJNd2KOGUYKBdCRTaWp+Bvi+PzGJgXo6Ont7yafkReiBIcObvAAIw7ujR5OpMSJdgYO4+sVE/Dlovr+46VcBVaHrbzAZ0tf+N9DQS1b9kXbDoItSXtsDIHNvV9v88qPoapgXmlamR15Znjxlc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=TBwyANlM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="TBwyANlM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9731AC2BCB7; Fri, 1 May 2026 12:35:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1777638949; bh=xvSVvF9WrgDkC4Y95og+EY5X2F5L2VauJZ6etEhWdc4=; h=Date:To:From:Subject:From; b=TBwyANlMd2HQMP9UDHBXWVLEcuJbacW33RZGfYFCVzWJrfYWp+5yOoySIe3rZeOCY wDx8zMq2aTiirUpVbJjh/ofRMpaDgzkGWTwBXM6bY4a9x68D82iws1X/Lkm+slkNPf bJ/vofX6DJfhAgW+AnY9XpcQh6rosUZdzIn4Gc2Y= Date: Fri, 01 May 2026 05:35:49 -0700 To: mm-commits@vger.kernel.org,vbabka@suse.cz,tj@kernel.org,shakeelb@google.com,mhocko@kernel.org,longman@redhat.com,hannes@cmpxchg.org,cl@linux.com,li.wang@linux.dev,akpm@linux-foundation.org From: Andrew Morton Subject: + selftests-cgroup-include-slab-in-test_percpu_basic-memory-check.patch added to mm-new branch Message-Id: <20260501123549.9731AC2BCB7@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: selftests/cgroup: include slab in test_percpu_basic memory check has been added to the -mm mm-new branch. Its filename is selftests-cgroup-include-slab-in-test_percpu_basic-memory-check.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-cgroup-include-slab-in-test_percpu_basic-memory-check.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Li Wang Subject: selftests/cgroup: include slab in test_percpu_basic memory check Date: Fri, 1 May 2026 10:20:58 +0800 test_percpu_basic() currently compares memory.current against only memory.stat:percpu after creating 1000 child cgroups. Observed failure: #./test_kmem ok 1 test_kmem_basic ok 2 test_kmem_memcg_deletion ok 3 test_kmem_proc_kpagecgroup ok 4 test_kmem_kernel_stacks ok 5 test_kmem_dead_cgroups memory.current 11530240 percpu 8440000 not ok 6 test_percpu_basic That assumption is too strict: child cgroup creation also allocates slab-backed metadata, so memory.current is expected to be larger than percpu alone. One visible path is: cgroup_mkdir() cgroup_create() cgroup_addrm_file() cgroup_add_file() __kernfs_create_file() __kernfs_new_node() kmem_cache_zalloc() These kernfs allocations are charged as slab and show up in memory.stat:slab. Update the check to compare memory.current against (percpu + slab) within MAX_VMSTAT_ERROR, and print slab/delta in the failure message to improve diagnostics. Link: https://lore.kernel.org/20260501022058.18024-3-li.wang@linux.dev Signed-off-by: Li Wang Reviewed-by: Waiman Long Cc: Christoph Lameter Cc: Johannes Weiner Cc: Michal Hocko Cc: Shakeel Butt Cc: Tejun Heo Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- tools/testing/selftests/cgroup/test_kmem.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) --- a/tools/testing/selftests/cgroup/test_kmem.c~selftests-cgroup-include-slab-in-test_percpu_basic-memory-check +++ a/tools/testing/selftests/cgroup/test_kmem.c @@ -353,7 +353,7 @@ static int test_percpu_basic(const char { int ret = KSFT_FAIL; char *parent, *child; - long current, percpu; + long current, percpu, slab; int i; parent = cg_name(root, "percpu_basic_test"); @@ -379,13 +379,14 @@ static int test_percpu_basic(const char current = cg_read_long(parent, "memory.current"); percpu = cg_read_key_long(parent, "memory.stat", "percpu "); + slab = cg_read_key_long(parent, "memory.stat", "slab "); - if (current > 0 && percpu > 0 && labs(current - percpu) < - MAX_VMSTAT_ERROR) + if (current > 0 && percpu > 0 && slab >= 0 && + labs(current - (percpu + slab)) < MAX_VMSTAT_ERROR) ret = KSFT_PASS; else - printf("memory.current %ld\npercpu %ld\n", - current, percpu); + printf("memory.current %ld\npercpu %ld\nslab %ld\ndelta %ld\n", + current, percpu, slab, current - (percpu + slab)); cleanup_children: for (i = 0; i < 1000; i++) { _ Patches currently in -mm which might be from li.wang@linux.dev are selftests-cgroup-skip-test_zswap-if-zswap-is-globally-disabled.patch selftests-cgroup-avoid-oom-in-test_swapin_nozswap.patch selftests-cgroup-use-runtime-page-size-for-zswpin-check.patch selftests-cgroup-rename-page_size-to-buf_size-in-cgroup_util.patch selftests-cgroup-replace-hardcoded-page-size-values-in-test_zswap.patch selftest-cgroup-fix-zswap-test_no_invasive_cgroup_shrink-on-large-pagesize-system.patch selftest-cgroup-fix-zswap-attempt_writeback-on-64k-pagesize-system.patch selftests-cgroup-test_zswap-wait-for-asynchronous-writeback.patch selftests-cgroup-fix-hardcoded-page-size-in-test_percpu_basic.patch selftests-cgroup-include-slab-in-test_percpu_basic-memory-check.patch