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Aivazian" , Alexander Viro , Christian Brauner , Jan Kara , Namjae Jeon , Sungjong Seo , Yuezhang Mo , Dave Kleikamp , Ryusuke Konishi , Viacheslav Dubeyko , Konstantin Komarov , Bob Copeland , "Matthew Wilcox (Oracle)" , Andrew Morton , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, jfs-discussion@lists.sourceforge.net, linux-nilfs@vger.kernel.org, ntfs3@lists.linux.dev, linux-karma-devel@lists.sourceforge.net, linux-mm@kvack.org, "Darrick J. Wong" Subject: Re: [PATCH RFC v2 1/2] filemap: defer dropbehind invalidation from IRQ context Message-ID: References: <20260225-blk-dontcache-v2-0-70e7ac4f7108@columbia.edu> <20260225-blk-dontcache-v2-1-70e7ac4f7108@columbia.edu> 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-Stat-Signature: jo9raj45thtd6cm7wpejan6pc9c65zeq X-Rspamd-Queue-Id: 25503C0008 X-Rspamd-Server: rspam07 X-Rspam-User: X-HE-Tag: 1772143459-576740 X-HE-Meta: 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 iSh/Wwk8 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Feb 25, 2026 at 03:52:41PM -0700, Jens Axboe wrote: > One solution could potentially be to use per-cpu lists for this. If you > have N threads working on separate block devices, they will tend to be > sticky to their CPU anyway. Having per-cpu lists would be nice, but I'd really love to have them in iomap, as we have quite a few iomap features that would benefit from generic offload to user context on completion. Right now we only have code for that in XFS, and that's because the list is anchored in the inode. Based on the commit message in cb357bf3d105f that's intentional for the write completions there, but for all other completions a generic per-cpu list would probably work fine.