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Howlett" , Jann Horn , Pedro Falcato , Matthew Wilcox , Jan Kara , Dave Hansen , Suren Baghdasaryan , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 0/2] mm: avoid redundant reads of the vm_refcnt cacheline in anonymous faults Message-ID: References: <20261110000002.1834454-1-san55@wisc.edu> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261110000002.1834454-1-san55@wisc.edu> X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: DE7131C0004 X-Stat-Signature: tfsregq7oqxjsq1pjfpoijycmrzsgcij X-Rspam-User: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-HE-Tag: 1794308597-386398 X-HE-Meta: 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 CHc4jORJ gPdmdnq5OtR7n/y4KCmJICSmOKmR/CdWlz+Pue+ebqxo8zJkk9LFsC8qKnLODh/GZcxqZ+E5ijQszbOyJ6VIoAYS1S0NSW6BFCJCjSFEX9mb7EG/nI52d+xpC3Se8r5h0QAWhaN+5RHfSSclvzR1phVfeLzFfg53Z5AuZ53i7bFSuCS5nlekWFl5RLVYwfsx/ka6B5ezDcvNnUZqWJMPc1t8d1+VDN3ZOguUSBd8hzVOZJnc9YAQw1CjNjkQGeNuBGgGRicW3lGccDfIlbR1wfr/pkhOOala8EYR8SMlAL/bEuHf+5xel6hLCy/ZT6gGe0oogV5gqbbl2sGYtwVHRCZe2xmccBP4SAg29zsEiRPbZqPQAcz7x7y/ngg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Thanks for the report. You are a complete newcomer to mm, and you are sending very subtle changes to a core part of it, so I am not confident that you have the depth of understanding the kernel requires for such work. See https://docs.kernel.org/process/generated-content.html I'll therefore take over this change and treat this as a bug report. I will give you due credit for reporting the issue of course. I'd like to collaborate on the perf measurements however, so if you could re-run your test results on my series when I send it that'd be appreciated. In general it seems that the actual issue is the debug assertion, given you state only vma_has_anon_rmap() as a problem here. In general in future - while we're fine with you using LLMs, newcomers should work on small, incremental changes to mm to build up understanding first. -- Cheers, Lorenzo