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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Rik van Riel , Harry Yoo , Johannes Weiner , Shakeel Butt , Baolin Wang , "Darrick J. Wong" , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Kiryl Shutsemau Subject: Re: [RFC, PATCH 0/2] Large folios vs. SIGBUS semantics Message-ID: References: <20251020163054.1063646-1-kirill@shutemov.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Rspam-User: X-Stat-Signature: 3965nnhx48mg4qh15fzsca5intecgf5u X-Rspamd-Queue-Id: 1263320003 X-Rspamd-Server: rspam09 X-HE-Tag: 1761027171-146339 X-HE-Meta: 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 Y0uxsKhB gXfw5raot2fVMm4z8LDr9NGzQvJMzrPm+b36jnFqye6RwngdTa6SNcgTpS3NMFUBOB3Z1DxVXGCc4CwZfUD1SS8DGJR3DN3aOiFdPm1gMGU4q7qiPNUOLVtusFjZzdys4hPSDWZsiHHb+H3+ssmarcjhCYHFJgWrxyhQndnu+pbjSSi3tvUDVmwnVtpp6LR6c9aUZIW77Yhll9IF/Nve5k+TDzn8o+/lP8QjDsO6x+cc8D2KOYfhMs4o71Dg4VLtEdqy02Ao8OJl100CBnquX8KhmuOrPs3xblMUrOXmTexfHCl+eFhlMd+SxQNlGJfj0CFRCpW7sedShYVXA0bQrJMWHei1D1vruqdwKbPuBt2LOtXAIPHptoqTYL8Q1hYletRoZcL7TFsLp11Zo136xDFxlWN2lRzlow3b1t5vznXpYGig= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Oct 21, 2025 at 10:28:02AM +1100, Dave Chinner wrote: > Fundamentally, we really don't care about the mapping/tlb > performance of the PTE fragments at EOF. Anyone using files large > enough to notice the TLB overhead improvements from mapping large > folios is not going to notice that the EOF mapping has a slightly > higher TLB miss overhead than everywhere else in the file. > > Please jsut fix the regression. Yeah. I'm not even sure why we're having this discussion. The behavior is mandated, we have test cases for it and there is literally no practical upside in changing the behavior from what we've done forever and what is mandated in Posix.