Messages in this thread | | | Date | Fri, 12 Jan 2007 23:52:02 +0300 | From | Michael Tokarev <> | Subject | Re: O_DIRECT question |
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Michael Tokarev wrote: [] > After all the explanations, I still don't see anything wrong with the > interface itself. O_DIRECT isn't "different semantics" - we're still > writing and reading some data. Yes, O_DIRECT and non-O_DIRECT usages > somewhat contradicts with each other, but there are other ways to make > the two happy, instead of introducing alot of stupid, complex, and racy > code all over.
By the way. I just ran - for fun - a read test of a raid array.
Reading blocks of size 512kbytes, starting at random places on a 400Gb array, doing 64threads.
O_DIRECT: 336.73 MB/sec. !O_DIRECT: 146.00 MB/sec.
Quite a... difference here.
Using posix_fadvice() does not improve it.
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