Messages in this thread |  | | Date | Tue, 4 Sep 2001 03:32:43 -0500 | From | Bob McElrath <> | Subject | Re: using O_DIRECT |
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Andrea Arcangeli [andrea@suse.de] wrote: > On Mon, Sep 03, 2001 at 03:13:42PM -0500, Bob McElrath wrote: > > I have written a small program to use O_DIRECT (attached), after > > applying your patch o_direct-14 to kernel 2.4.9. Opening the file with > > O_DIRECT is successful, but attempts to write to the fd return EINVAL. > > > > Am I doing something wrong? Should I have to recompile glibc too? > > eh, the alignment and size of the buffer have basically the same > restrictions of running read/write on a raw device, with the only > difference that for rawio the granularity is the hardblocksize, while > for O_DIRECT the granularity is the softblocksize of the filesystem.
Ah, thanks, it's working now. Makes sense that it should use blocksize granularity...
> We'll have to relax the granularity of the I/O down to the hardblocksize > for O_DIRECT too eventually.
I don't really care about the granularity. The bigger the better, actually, since I'm streaming data to disk quickly. ;)
Thanks, -- Bob
Bob McElrath (rsmcelrath@students.wisc.edu) Univ. of Wisconsin at Madison, Department of Physics [unhandled content-type:application/pgp-signature] |  |