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 51A1932B981; Thu, 26 Mar 2026 23:01:32 +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=1774566093; cv=none; b=WbsrlCVq7R4zfW73IRJTqiTTWJScfFDvHydWCBNoDLBOKwS5HvrSNAq4tlT7Io5hvaj1ygB1sz4038aqEmjb6gPT26U7T3UzISndIKKXqGMcUJ2Le58aMSa0/Brd2fGgFhe4QtunsESaEhWkr7uWJ3CnCTjGUfTSlnaGMBkRZnw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774566093; c=relaxed/simple; bh=cDTsrbhXw5vlpWEEc4LUAv5/LmEmN3f96wzlQ2E2W8I=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=nm9FwBtY7glHJ7YVgU4i+IoufKAURoundBh8oCnB+d7dkTOAXDDKraeZLwG8w2kerruEt4odDN7uRBQBePfLq1vVWAfutMxgflvrqWWw7DeYwZ5cHDdn8HzMC9wlSrIdS3KHg1fs8lcArNViYJHOH761WiMdf9DD+QtvYG8/Pjg= 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=UYb54Kxx; 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="UYb54Kxx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38630C19424; Thu, 26 Mar 2026 23:01:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1774566092; bh=cDTsrbhXw5vlpWEEc4LUAv5/LmEmN3f96wzlQ2E2W8I=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=UYb54Kxx65LLq0qlCcbXJfPX2Ur0P4LcbnlozgE0qzkgcE1vgcXIHYzjmSdiFd72C b537IQfQ/372i9zPL2tZI3RdE05VqCLNNhSFjzK1VEUE9GnVk9PabkvstDOyRee/8R Tj1gSL8mE+nLLcG3D0whAWOsGKQxGSlBJWP9AU/0= Date: Thu, 26 Mar 2026 16:01:31 -0700 From: Andrew Morton To: Li Wang Cc: yosry@kernel.org, nphamcs@gmail.com, hannes@cmpxchg.org, mhocko@kernel.org, mkoutny@suse.com, muchun.song@linux.dev, tj@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, longman@redhat.com, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v5 0/8] selftests/cgroup: improve zswap tests robustness and support large page sizes Message-Id: <20260326160131.9f3df79db328ba2095511161@linux-foundation.org> In-Reply-To: <20260326032658.96819-1-liwang@redhat.com> References: <20260326032658.96819-1-liwang@redhat.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@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, 26 Mar 2026 11:26:50 +0800 Li Wang wrote: > This patchset aims to fix various spurious failures and improve the overall > robustness of the cgroup zswap selftests. > > The primary motivation is to make the tests compatible with architectures > that use non-4K page sizes (such as 64K on ppc64le and arm64). Currently, > the tests rely heavily on hardcoded 4K page sizes and fixed memory limits. > On 64K page size systems, these hardcoded values lead to sub-page granularity > accesses, incorrect page count calculations, and insufficient memory pressure > to trigger zswap writeback, ultimately causing the tests to fail. > > Additionally, this series addresses OOM kills occurring in test_swapin_nozswap > by dynamically scaling memory limits, and prevents spurious test failures > when zswap is built into the kernel but globally disabled. Thanks. AI review flagged a few potential issues. https://sashiko.dev/#/patchset/20260326032658.96819-1-liwang%40redhat.com Please take a look - I'm interested in learning how may of these you feel are worth addressing. The sysconf retval one is real, pretty minor. I'd be inclined to ignore the unchecked-malloc-return one. It's userspace, it's selftests. If a malloc() fails then gee, fix your machine and run it again. Plese understand that I'm serious trying to slow things down now (https://lkml.kernel.org/r/20260323202941.08ddf2b0411501cae801ab4c@linux-foundation.org). Maybe we can weasel out of that for selftests but I'd rather not. That means post-7.1-r1 for this patchset, so please plan to resend at that time. If memcg maintainers decide that this material should target the upcoming merge window then OK,