Messages in this thread | | | Subject | Re: [PATCH 1/7] block: Add block_flush_device() | From | Chris Mason <> | Date | Mon, 30 Mar 2009 16:15:08 -0400 |
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On Mon, 2009-03-30 at 22:09 +0200, Andi Kleen wrote: > Chris Mason <chris.mason@oracle.com> writes: > > > > As far as I know, reiserfs is the only one actively using it to choose > > different code. It moves a single wait_on_buffer when barriers are on, > > which I took out once to simplify the code. Ric saw it in some > > benchmark numbers and I put it back in. > > > > Given that it was a long time ago, I don't have a problem with changing > > it to work like all the other filesystems. > > When it was a win on reiserfs back then maybe it would be a win > on ext4 or xfs today too?
It could be, but you get into some larger changes. The theory behind the code was that writeback cache is on, so wait_on_buffer isn't really going to give you a worthwhile error return anyway. Might as well do the wait_on_buffer some time later and fix up the commit blocks if it didn't work out.
We're still arguing about barriers being a good idea all these years later, and the drives are better at them than they used to be. So, I'd rather see less complex code in the filesystems than more.
-chris
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