On Sat, Jun 23, 2012 at 09:39:55AM +1000, Dave Chinner wrote: > Hmmmm. How often do we get real io completion occurring before we > call _xfs_buf_ioend() here? I can't see that it is common, so this > is probably fine, but perhaps a few numbers might help here? If it > is rare as we think it is, then yeah, that would work.... The only case where I can see it ever hapen is when sending tons of separate I/Os in one go to a reall fast device, e.g. a very fragmented large directory to superfast battery backed dram device. And even then I don't think it matters very much - for reads we generally do not have an b_iodone handler attached, so for these the change does not make any different. For delayed writes the additional context switch also doesn't have a major impact on performance, so the only thing where we could see a difference is synchronous writes, of which we don't have a lot left, and essentially none unless the shrinkers kick in and need to do synchronous reclaims. _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
