Messages in this thread | | | From | Bill Davidsen <> | Subject | mmap vs. O_DIRECT | Date | Tue, 09 Nov 2004 19:05:13 -0500 |
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I have an application which does a lot of mmap to process its data. The huge waitio time makes me think that mmap isn't doing direct i/o even when things are alligned. Before I start poking the code, is there a reason why direct is not default for i/o in page-size transfers on page size file offsets? I don't have source code, but the parameters of the mmap all seem to satisfy the allignment requirements.
I realize there may be a reason for forcing the i/o through kernel buffers, or for not taking advantage of doing direct i/o whenever possible, it just doesn't jump out at me.
-- -bill davidsen (davidsen@tmr.com) "The secret to procrastination is to put things off until the last possible moment - but no longer" -me - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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