From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 1FE423D9540; Thu, 27 Aug 2026 22:58:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787871518; cv=none; b=omCm+E2SotpWojJFEmEB1OsQzG+GXkJpdIxhxEjL9z4KkhvggUXV6JYvDsNgZvs/3ltAj7CMLADoKgJJ1VMVeo1DxKvBZtkqoS3bYkHyqnPjQy1d2ClgreEVrcIVtP3ULYtW8FStwStj4B2uQNxRtua0gb+w3t4YbBzOXl26pFU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787871518; c=relaxed/simple; bh=5q1K0Y4OgILhKpFqC6V0wh5KJHs9+MupmQvC1o1Trrw=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=o6TAR6jY40lWrZioC77YfDVAREC3XrKfHj15rVvnk3r+Zgd8tOSMCBXAGt4QXCW8s8ldshnZC1foN0DsvYfAgO7c1hZuyaYtyowQ4vamgARF7o9wcNF9Yhl01p2PziDDuJo853gnjKN3pepualGB453NHV4t85M9PHmqZ3vXsuY= 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=uYjmXJ0o; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="uYjmXJ0o" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 191751F000E9; Thu, 27 Aug 2026 22:58:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1787871508; bh=o+CbAiQiCIV+X/Q5GkUr3xptEh0VJF+8loj/KjFok3E=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=uYjmXJ0o0nclaaJYRmGvcWh+PMXoFy/4V5w+QgCWh8eiWJb/86f00TXFVBhbrLHhB 8lQosBwA0un/NICBloB17fuu/r+IR/E6r6IhUBF68l7qps2RaUPak5VGjmfyDXCX/Q bRnygD5L99ynxU0xzCPn1/M1i0SWw9TtVfU7HRFk= Date: Thu, 27 Aug 2026 15:58:27 -0700 From: Andrew Morton To: Wilson Felipe Pereira Cc: Johannes Weiner , Yosry Ahmed , Nhat Pham , Chengming Zhou , Tejun Heo , =?ISO-8859-1?Q?"Michal_Koutn=FD"?= , Shuah Khan , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 0/2] selftests/cgroup: fixes for test_zswap on single core VM Message-Id: <20260827155827.e40d5d88cee174437a16f432@linux-foundation.org> In-Reply-To: <20260827034807.2822234-1-wfelipe@google.com> References: <20260827034807.2822234-1-wfelipe@google.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 27 Aug 2026 03:47:40 +0000 Wilson Felipe Pereira wrote: > This series fixes two test failures in test_zswap observed when running on > a single-core VM (-smp 1) with 4GB of RAM. > > Patch 1 addresses a race condition in test_zswap_writeback() where > waitpid() returns before the exiting child process is switched away by the > kernel, causing an immediate write of "+memory" to cgroup.subtree_control > to fail with -EBUSY. We fix this by waiting for cgroup.events to report > "populated 0". > > Patch 2 fixes an implicit unsigned conversion bug in test_no_kmem_bypass() > where small negative timing differences between debugfs stored_pages and > cgroup zswapped bytes caused the comparison to falsely fail due to > unsigned promotion. Thanks. Sashiko thinks there remain some signedness/truncation/overflow issues in there: https://sashiko.dev/#/patchset/20260827034807.2822234-1-wfelipe@google.com