Messages in this thread | | | From | Bill Davidsen <> | Subject | Re: O_DIRECT question | Date | Fri, 26 Jan 2007 13:23:28 -0500 |
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Denis Vlasenko wrote: > On Thursday 25 January 2007 21:45, Michael Tokarev wrote: >> Phillip Susi wrote: >>> Denis Vlasenko wrote: >>>> You mean "You can use aio_write" ? >>> Exactly. You generally don't use O_DIRECT without aio. Combining the >>> two is what gives the big win. >> Well, it's not only aio. Multithreaded I/O also helps alot -- all this, >> say, to utilize a raid array with many spindles. >> >> But even single-threaded I/O but in large quantities benefits from O_DIRECT >> significantly, and I pointed this out before. > > Which shouldn't be true. There is no fundamental reason why > ordinary writes should be slower than O_DIRECT. > Other than the copy to buffer taking CPU and memory resources.
-- Bill Davidsen <davidsen@tmr.com> "We have more to fear from the bungling of the incompetent than from the machinations of the wicked." - from Slashdot
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