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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 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 X-Stat-Signature: hffuaz1wibo8yoooi4i654w19giozx9g X-Rspam-User: X-Rspamd-Queue-Id: 3E73218000B X-Rspamd-Server: rspam07 X-HE-Tag: 1778262057-599780 X-HE-Meta: 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 5TOF5nKA rmgjISg2WdWQIOEKgLl1JktDSpK7VUy33gI30MVkNmPtwNYGBgKE2AtlVxU62avvwT3Dz3nxMXQ0VcGG/AMvBi3T4GpgrqMdzbHJk3rIptpq/dLWcHdr02V13uqin0JP9Pryd0CqUlhI/rAjZQNzkDb7BHZUjmzxfIFRN54xCoyA3GefWYUyWfBMQR/dmcciF7GyLCsLLQfrYrAS9eslErZ6k0natHp0hxO+g9vtR15LcM17fg4u16lRmKgRRUkgRk1bvOIREcfiXeQR+uWFXUsxSdRdBLSEsm2/sfH8qXQPIEi+kL7aDD1xwH5a7GkGG7nHVoe5zqjS/Eqpvf3q3CXbULGdfw7g8WoJ6eSWWF3DnAWnk2vOIFYHR45qpId0s5Khz7XO5cDXtiMnVwLrOfW0vSceSdDpaBcbFhco2ZDczLaWLhzlucCydNA== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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? >