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b=Fn8xnnaCWaF0vyPtBMo2X4/gXck247qHSFTKsAYHkaVbw0FUqJrs7SKseePgrdVcW 4v7BaTGoqZG05LRaPKk+Fzer0c4BuQMx9wfQ1lnjGp9PlyPpcZS6kvU1ff/Jo2ECj/ Wr+L1i/SDWv9cDbNP+2TI7WWnqmusfdrW2LgNd9g= Date: Fri, 8 May 2026 10:29:48 -0700 From: Andrew Morton To: hawk@kernel.org Cc: linux-mm@kvack.org, Vlastimil Babka , 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 Subject: Re: [PATCH 1/2] mm/page_alloc: add tracepoints for zone->lock acquisitions Message-Id: <20260508102948.b1c687e623fabec65580f258@linux-foundation.org> In-Reply-To: <20260508162207.3315781-1-hawk@kernel.org> References: <20260508162207.3315781-1-hawk@kernel.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 334AD4000F X-Stat-Signature: rnq8g8bjgcsks9cwsc65bbo3g1bge7a3 X-Rspam-User: X-HE-Tag: 1778261390-696760 X-HE-Meta: U2FsdGVkX18PPP4xVSkhblo1aupTBJLPuu4UZjGdKJlqXRZ3DhfraAMndk+sX5eFct8wCgy/i3YgrVgOQZ1o92YXGpscsHkseFLmPuBkDWCMQli/oNA4lIsuwsFWXd/qfP6WvmxbN+lQI8xr9W5SngAeSaaS8meG6XmgzHCEIc+qqwZKqbscrivrlOHmhz3loePrm036J7lCk0ZFMvvK7OKLBbpk7vkXS18Y3AvWg9/O7ii15XeoWWFPeMnf2/XKxdmY62HYXgCG+J66wSwdWS0CjGetOZ5RUTl4jrxp4fnOIECDuJxmJKhPxl+2so3yhHqW/GNS96PJM0OIw1KaZjorWG671PP35ml0YpUVwmIkWhIeawKGo1L5RPgW9i//brnQDK7XV4UM1rdEoTODgMsH2QxdS4G+b6jfa1wLMg0jac21GHHeVVzXwvT/Y5kggTs9u0Odk1nb1t+bPZREqi9cG4wZkN5or9VsIt7XPQvQKSue9AkMNn1Qfrvk0IlhNni9OQ3b18NcWZY0OMtx6fL7U3qeB+XCxfUFUcqG7C3yxSvsr97qbiiHg3DcNIgIAKdgTZFnhjZGzCnNefmH5zy+UNtz4l85NMXN9IQPbSdHuAFHEjY1uKfuP7O6uPW30wQLr+b4Kch8UfcFwrF1RH+bkW6manCCz1qN3qBv7ij66mt7BeXDELm08TvdYqBc1uUufENd5RRdhVA+nAh/t/UfConOEnIqi5ZhNsBfjuUIjJ9pxTItWKplWruhuYL/DSpKzjfvQwvFzkGuSa4dCo6XIbiBnssbQY46B6DrDY0Zc+UE25CqVNFeguUcZO6QDYWA7sPG2YOu9CqIp9J9b2YLVBvDYMfwvRyFlwVf9eAOT1TNiaW/E1neU4GR9Ac0ibjKaEkbs1rL4BnxGbfd7g4jr+SJw+vN7VTeG9cwRpodZpYQqujZ8bBxV//EHt57+2suVg3/gyKHb5ogLQ0 N7JHGWW8 Pmheiq34uQXnTlPNO3ppUwbUFMaxAUh5LFgsiQDXxWeAHrwQLLqqKyF34ZtMINAnyFgaIz3X+z2W0rt0rf7P+W2Tqpix7TAk5rTaF6cJtnWUpppcwrf0oVvj0gKRA+LmtRWB9NGpyQ0hCYDsnosvwAM22el0UYI5KZqhlPrHgeT76QGyjXIJyDEXjExw7bqz1hJPaYsxg6Pfre6K/RJQTXuaptiWYx9+fPpqZyUkV79wdLwFgC4NigkKcOcE/KXyXDE7A/BkUCDySoWOm2pDcM+1cdDZ0BUwT9wMxuH+JViAZDOTeNhNG3a4bceB9XIDAkzVFir9s1xeSwcJIwICy3KberdybLgUD+QHr8GIOpLdJaNiJZc+msMmeYrEgpZZbuVHo Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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. 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?