Messages in this thread | | | Date | Fri, 17 Oct 2003 08:46:45 +0200 | From | Jens Axboe <> | Subject | Re: [PATCH] ide write barrier support |
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On Thu, Oct 16 2003, Mudama, Eric wrote: > > On Tue, Oct 14 2003, Greg Stark wrote: > > Jens Axboe <axboe@suse.de> writes: > > > There's also the case of files opened with O_SYNC. Would inserting a > > > write barrier after every write to such a file destroy performance? > > > > If it's mainly sequential io, then no it won't destroy performance. It > > will be lower than without the cache flush of course. > > If you flush a cache after every command in a sequential write, yes, you'll > destroy performance. How much you destroy it is a function of command size > relative to track size, and the RPM of the drive.
Yes you are right, my logic was a bit backwards. But you don't have to issue a flush after every write, thankfully. But lets still not forget that performance means nothing if integrity isn't guarenteed.
-- Jens Axboe
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