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See http://www.infradead.org/rpr.html X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: BB41214000B X-Stat-Signature: dxy8r67m49asnbq666bopcmhct9rboyo X-HE-Tag: 1761032890-188187 X-HE-Meta: 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 /bBL4ONq /hnLh9mYz5AojoNCJZszCqWkXk2YTtznxXDip7iKEYw/qwFKZnbi+Aumhm2xi6cWpAECbEGZsUWXrVqPZEx6dj4oEbWS4K7McasPYvFP4YYquPmJir4aOZaUH09HFf7V9bF8TXLP6FSZ/IP8845TJphRhDd9PgsyU1UPMYTn5tUA1RAxMsr+TXLMORHDLm4b1W0+T0g+4AhSqXHoANNEm11tx3/BLQUZUIcGafDkE+eYf1lVvv8EfSd7AiSbWRfCJlC/H6h8s5OSdLQbNWw38y0a8aeQAX1tdLwkPb9xeT15QW78KH9hJ88nuFs27BoMuauDMbbEPiaB9spkDv2ecOzHJrjBaJbSvfwKMDd7+JH3GiwexCdkRdsNM8AKChPBAJ+Tb/KbhA4lJaXV7X/uM/5wtBF1hrWICG6/fKEGIzFoqdPFluJdL59WcUFLvDpqhICx2tNJFUfM/vfoKBU+WYGjRL0s9UtpfK6z4 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 01:47:03PM +1030, Qu Wenruo wrote: > Off-topic a little, mind to share the performance drop with PI enabled on > XFS? If the bandwith of the SSDs get close or exceeds the DRAM bandwith buffered I/O can be 50% or less of the direct I/O performance. > With this patch I'm able to enable direct IO for inodes with checksums. > I thought it would easily improve the performance, but the truth is, it's > not that different from buffered IO fall back. That's because you still copy data. > So I start wondering if it's the checksum itself causing the miserable > performance numbers. Only indirectly by touching all the cachelines. But once you copy you touch them again. Especially if not done in small chunks.