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 4665C3D810D; Fri, 8 May 2026 17:38:14 +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=1778261894; cv=none; b=jicF/XSGRiTXqGqf+BONBF50C9KRIQ7fjTLCqm6w0sCLQzuHDkpQzTNkr2O4xZaMWfTRlZaQVlRXAa5Lk61vpIfDbOGjfDytuQvbbEYloWEGBdGeoO873WCp/sDeAXV6vbjnlowcfi1LgGt5Yf9TtOrtxkzTml90thmv5E/rNSo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778261894; c=relaxed/simple; bh=8O1+aE8sZNGhibwsXUzGKlGSLLVTQImi02JgLRN5+Wo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=LJovh+p1OvfL4xNYZaVhvpKJa0p2LE96GH3AlOeDOrIw+PaD49IQ9Ar0rZpr5RJYKci/vEymfyBBaNHr5PxH8US2T4LpXdS/GoFmNTsRxxYRlAIokCiZWMr4l88/1LWXEKkOSrbtPHDXfC98Gu4NNx2ZEWUQd8DUXlnZA9NP6Ow= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XMhg/zvt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="XMhg/zvt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48A70C2BCB0; Fri, 8 May 2026 17:38:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778261894; bh=8O1+aE8sZNGhibwsXUzGKlGSLLVTQImi02JgLRN5+Wo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=XMhg/zvtUQbsUJj0jEEmzzEM1sOuu2PmK5XEbqJjnz8o2pgGld2ayg7B3R8Gv48Se SmstiDzpRJMQD++m9DEwq/Pu6nQPU4xv1OqaIy/PzhfSY41PXkak32EB72oP4Ti6rG uMcVYCmNg5miEcjUE3rMaaeI0s3eawFjKU9a1KMFzXzW0OereAzwNY+rHfs34M23jD KxIiqOHzrUuvw8uKG3GOmDHICi7Af+HNsA+C5PHINOKJzauazTtSt4ZdZszBLQxv8v 8Es+m9P0oiFJzZ8g+qeYVdj4nT2saQc/XKe/I1+f1XLeSyKjKCIJxedx3amZxr544i so18H0arHs96g== Message-ID: <832e4333-4079-4865-8ad8-3dd8868fb964@kernel.org> Date: Fri, 8 May 2026 19:38:09 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] mm/page_alloc: add tracepoints for zone->lock acquisitions To: Andrew Morton , hawk@kernel.org, Dmitry Ilvokhin , Matthew Wilcox Cc: linux-mm@kvack.org, Steven Rostedt , Suren Baghdasaryan , Michal Hocko , Zi Yan , David Hildenbrand , Lorenzo Stoakes , Shuah Khan , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, kernel-team@cloudflare.com References: <20260508162207.3315781-1-hawk@kernel.org> <20260508102948.b1c687e623fabec65580f258@linux-foundation.org> From: "Vlastimil Babka (SUSE)" Content-Language: en-US In-Reply-To: <20260508102948.b1c687e623fabec65580f258@linux-foundation.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/8/26 7:29 PM, Andrew Morton wrote: > e .configOn Fri, 8 May 2026 18:22:06 +0200 hawk@kernel.org wrote: > >> Add tracepoints to the page allocator fast paths that acquire >> zone->lock, allowing diagnosis of lock contention in production. > > Thanks, I'm surprised we haven't done this yet. There was a recent attempt [1]. Not being a generic solution wasn't welcome. [1] https://lore.kernel.org/all/cover.1772206930.git.d@ilvokhin.com/ > Unfortunately "mm: use spinlock guards for zone lock" messed this up > (https://lore.kernel.org/all/cover.1777462630.git.d@ilvokhin.com/). > > So please let's give it a few days for reviewers to comment then redo > against mm.git's mm-unstable branch?