From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-172.mta0.migadu.com (out-172.mta0.migadu.com [91.218.175.172]) (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 2D70B3655EC for ; Thu, 30 Jul 2026 01:48:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785376101; cv=none; b=RnJWTdjg3DHOMU3HzmSXs8YaXiMdfW3JwNOyEeAaYTzYHsTjPQIVZdoqzal171LTuly8wXyOO0gLJpvO2rN4ESj4wg8faZyN3Hh8ofY6xX2DSqo66qy1YW49CCwacgNsYGk5iWeFPUM7AOhDTAi0G0Uq5eigoOqCNWwGVLPI02k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785376101; c=relaxed/simple; bh=KLDja6n4BKo/QrapPt4yWwqelwNdhgNa6lu6UQ9kO60=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=LnoKUyBTgjZGI6brQLoy0UY4Q36EcZSQOLGIctjYNoYxA02+GId0wh0SIwOPkE15SwVUewj3FfMV6xuBp5QogJCIBQvKgoT3fq0zDB+K4i0ZqAZdgHaYyUsircVWTKIXL44trTNbkM0ncfC4xCDpJiASqnlJJrQvhy674XXsGEs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=snIU8Z+v; arc=none smtp.client-ip=91.218.175.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="snIU8Z+v" Message-ID: <0710df28-5870-4d33-aba1-085756290856@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1785376095; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=k2kUWZ0xcdYFc/4dDu905x5nCY+rKqCzP7jv+c5usrE=; b=snIU8Z+vX8Ry3ANjvdEYi7mUuak8bA4lZ6UeOPKRCzKxibeH87AGjK/ZyBXsS4tMx9lBNK Mzd0mnR5q8KJP5C42BVPKioszvVLq/1wsuvkovqsa7W4tXiAkmPFPsQZAYVC7FxWHp8kRD dxlFXpx/Wgw/KKuhdz5ZbSnUHDWHtzs= Date: Thu, 30 Jul 2026 09:48:44 +0800 Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH] mm: memcg: stop reclaim when a limit update is superseded To: Michal Hocko Cc: Johannes Weiner , Roman Gushchin , Shakeel Butt , Andrew Morton , Muchun Song , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Guopeng Zhang References: <20260724021805.1234583-1-guopeng.zhang@linux.dev> <615d091c-bd3b-4686-817e-5b29756542ff@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Guopeng Zhang In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 2026/7/29 16:02, Michal Hocko 写道: > On Wed 29-07-26 14:15:25, Guopeng Zhang wrote: >> >> >> 在 2026/7/27 21:58, Michal Hocko 写道: >>> On Mon 27-07-26 20:59:23, Guopeng Zhang wrote: >>>> >>>> >>>> 在 2026/7/27 16:16, Michal Hocko 写道: >>>>> On Fri 24-07-26 10:18:05, Guopeng Zhang wrote: > [...] >>> Is this trying to replicate any real workload? One would expect that >>> writers to limit do some sort of coordination otherwise the exact >>> behavior is not really well defined. >>> >> >> No, this was not motivated by a reported production workload. We found >> it through automated randomized testing for our cgroup observability >> work and reduced it to the reproducer above. > > This is an important detail to be mentioned in the changelog. Describing > motivation for a change is really important, especially if it has direct > impact in user interface behavior. Thanks for the guidance. I will take the feedback from this patch into account when preparing similar changes in the future.