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 B85AB410D34; Fri, 8 May 2026 17:40:56 +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=1778262056; cv=none; b=lAlMuW/iR+EOrcJNv8qgtbvVLk3yzOd/gMntatPhkWmb1zsdRmC36HasO3E7OkFRRekneWHBz7NtTvL4c1wsrHw2z9IXTg6WYuHSSMkUuPF7qG6c+iYelvJ/e+WF057bFjiPD1lnTIKyQ7NvOCNGV7KmpNwL0EGFfnS66lI6TyI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778262056; c=relaxed/simple; bh=/XMdVotwUAZISngQqqj5MIoZIgwfggXWKoKAcLMe8cA=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=ZwEVpt37KUSvCjFGVzTqiCdF6WuIa0x8iv6wcntf/YOahdukAFDsPYL7EBkRkkwAjFbMhMjefb0eWiryFw6xaHDofMD9DxLWj57zGcFTT4+TuVcVkQ60ss4Q52xw3BHQUUZ84l0wdjEmJGfjbZkm7sBvwyudmFmc4Zp9EPpsv+E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iomCB9gP; 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="iomCB9gP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B71AC2BCB0; Fri, 8 May 2026 17:40:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778262056; bh=/XMdVotwUAZISngQqqj5MIoZIgwfggXWKoKAcLMe8cA=; h=Date:Subject:From:To:Cc:References:In-Reply-To:From; b=iomCB9gPhjoBNsOLJ9ZqZ5N6KsyO+HSTdGjXRMgLrWeAuCQzg9NCYnZV5D0xKKh4Q 5w8scCy1kL789eFfK4CGcw/9Seh82TvZYFGiCTjOi8qo+eSOYvBPtn4U8YHyJIJz1L 0lqs8p8zq4lEtW5Lb6i5hXARsdaZbnyRiclNG8eOhhnJIpn85yMlgo61cCePGmSbeW 1JfBlVky+tnpKg6rPd7vMlc+atBvICMGykTbucdnQSqJTIu3OdD/vE202dh6yQLFjW 3MzBN9/BhMW5MLCBWnU0najLhjYuyU+Qs7SwJQA8GRsKIerHRjliDnu8eWGrSBX3Xf uud1TPcQLx9fQ== Message-ID: <4f61457e-deff-430f-8a1e-d3c33c925db3@kernel.org> Date: Fri, 8 May 2026 19:40:51 +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 From: "Vlastimil Babka (SUSE)" 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> <832e4333-4079-4865-8ad8-3dd8868fb964@kernel.org> Content-Language: en-US In-Reply-To: <832e4333-4079-4865-8ad8-3dd8868fb964@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/8/26 7:38 PM, Vlastimil Babka (SUSE) wrote: > 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/ And this is the generic solution I think? https://lore.kernel.org/all/cover.1777999826.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? >