From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793179193; b=Wk0W0QhCGmkHNM5yfoktoCvbytXbrAYUJK+HmfH4e8LB3d0dsipqMq7FkC5TfZb94yOK u6bwIvX4sEsf+Dc2w+44uyyj6v651X+hmtodQzIx/OMgT9jv6sIX2FKmxAVa1h6iGnWeg nZ2uhK9XnYx+MIV88FV4c5sfmQ9EkpEPjWbTIqyTBJGkY3zZdYS2DG2JAOXyFfoudv109 FLTK55P80xUtffEb4tPYFqnbcMuNybBKJ7g4NZAa2uXujZAIcM1AhyPqrnJbGlagZ6EU0 XsKdjhDZlAgx1N9HoDpna8DzO9MLy6Au9mAMBIQXzPB0t7hPARQcXYU10WAhOksh1Aw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793179193; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=dIQYEI2EXBN3ZRTF+vP2Ww75sjtd+SHDiG1ARLFc8yU=; b=sRwF/sFzLjTWxoaIEmRZgMVqiNXr4AKRpgy+R1a5fI9VhjLKdh6J3SB0fhCtKmffWsTz RjpXn60nX9xhuUyNqJrQmJRg5SLl4lkyQt4flb8edSPVIDv8BIHAKy8TObP3QKWfRKtTC xZMlonByR5rd8cyCWpT37iix/+0IZVjclygFqg8AXzazqjrCkhrknZJXqYD6Hg1K/p6Xx vbyIMh1sbc+QEaYFyXr4RKNfPRiSeIrWbfSpjusz5sb2CF1+62bYVrASWD81/SXkxFpSP vVZWyqcunILqofNT2dOWNyHsvJ8imtP/SS/uOAOE9NDNuJI7HWcsYXsTKAW+vtq56jg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=XM6ZOwO4; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 85BE7606A31A; Wed, 28 Oct 2026 09:19:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=XM6ZOwO4 Received: by smtp.kernel.org (Postfix) with ESMTPSA id A155B1F01825; Wed, 28 Oct 2026 09:19:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793179193; bh=dIQYEI2EXBN3ZRTF+vP2Ww75sjtd+SHDiG1ARLFc8yU=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=XM6ZOwO4JL0qURt+r1Tt40S78pKBud1WZEdBrmgnRYO1IHQx0nw0QpogbIOKyGmPe Km3z6nNDakO14FRuEqVD6fltowQlZ7IgPD5kjEDVcYIT1DkJWmyClJk0abCib41owt ySqTJ4L0jCS75jvustKWciug4KaYB90KVfbHVKFjON78MKKpMEI32cl6UGp/XSzUII Kt+zseF0qDmtZCYGqCVS+eiWZXxUj2/KE/n3JtTF2FAHW9dMBKdWWQ6H/zFUAAGvXn mIlgh8GMe/IxdPt8AUsOnaUV6MHtzeNJ/Fh2zHVde2ypPbt8fSQBCXfsZPFDK7ZnEF 8MYy195BPQYgA== Date: Wed, 28 Oct 2026 09:19:46 +0000 From: "Lorenzo Stoakes (ARM)" To: Suren Baghdasaryan Cc: akpm@linux-foundation.org, david@kernel.org, jannh@google.com, liam@infradead.org, willy@infradead.org, paulmck@kernel.org, pfalcato@suse.de, usama.arif@linux.dev, vbabka@kernel.org, linux-fsdevel@vger.kernel.org, yi1.lai@intel.com, oe-lkp@lists.linux.dev, lkp@intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] selftests/proc: use RSS in /proc/pid/smaps_rollup tearing tests Message-ID: References: <20261028051312.1505295-1-surenb@google.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261028051312.1505295-1-surenb@google.com> On Tue, Oct 27, 2026 at 10:13:12PM -0700, Suren Baghdasaryan wrote: > Pss metrics can be affected by map count even if VMA tree stays unchanged, > therefore test checking VMA tree integrity can't use them. Use Rss instead > and pre-populate the VMAs so that Rss changes if a VMA gets skipped or > double-counted. > > Fixes: ca5480fb53fa ("selftests/proc: add /proc/pid/smaps_rollup tearing tests") > Reported-by: kernel test robot > Closes: https://lore.kernel.org/oe-lkp/202610271934.fd287c3f-lkp@intel.com > Signed-off-by: Suren Baghdasaryan Seems sensible, I gather in general PSS is a less than ideal measure in these stats anyway :) Reviewed-by: Lorenzo Stoakes (ARM) > --- > tools/testing/selftests/proc/proc-maps-race.c | 11 ++++------- > 1 file changed, 4 insertions(+), 7 deletions(-) > > diff --git a/tools/testing/selftests/proc/proc-maps-race.c b/tools/testing/selftests/proc/proc-maps-race.c > index bf4c5073f6fc..b6d88afb252b 100644 > --- a/tools/testing/selftests/proc/proc-maps-race.c > +++ b/tools/testing/selftests/proc/proc-maps-race.c > @@ -528,13 +528,10 @@ static bool compare_smaps_rollup(FIXTURE_DATA(proc_maps_race) *self, > struct smaps_rollup_stats *actual) > { > /* > - * Clean/dirty metrics might change but Pss-related ones > - * should stay constant. > + * Clean/dirty metrics might change. Pss depends on map count and might > + * change as well. Rss should stay constant. > */ > - if (cmp_smaps_rollup_stat(expected, actual, Pss) && > - cmp_smaps_rollup_stat(expected, actual, Pss_Anon) && > - cmp_smaps_rollup_stat(expected, actual, Pss_File) && > - cmp_smaps_rollup_stat(expected, actual, Pss_Shmem)) > + if (cmp_smaps_rollup_stat(expected, actual, Rss)) > return true; > > print_smaps_rollup_stats("Expected stats:", self, expected); > @@ -759,7 +756,7 @@ FIXTURE_SETUP(proc_maps_race) > > for (i = 0; i < mod_info->vma_count; i++) { > mod_info->child_mapped_addr[i] = mmap(NULL, self->page_size * 3, prot, > - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); > + MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, -1, 0); > ASSERT_NE(mod_info->child_mapped_addr[i], MAP_FAILED); > /* change protection in adjacent maps to prevent merging */ > prot ^= PROT_WRITE; > > base-commit: 39274b454e9993cea319f4ac342a8082a9ee1730 > -- > 2.56.0.307.g5fe7bd680c-goog > -- Cheers, Lorenzo