On Saturday 08 September 2007 19:43, Goswin von Brederlow wrote: > Nick Piggin <[EMAIL PROTECTED]> writes: > > Lustre should probably have to be ported over to write_begin/write_end in > > order to use it too. With the patches in -mm, if a filesystem is still > > using prepare_write/commit_write, the vm reverts to a safe path which > > avoids the deadlock (and allows multi-seg io copies), but copies the data > > twice. > > Not quite relevant for the performance problem. The situation is like > this: > > lustre servers <-lustre network protocol-> lustre client <-NFS-> desktop > > The NFSd problem is on the lustre client that only plays gateway. That > is not to say that the lustre servers or desktop loose performance due > to fragmenting writes too but it isn't that noticeable there.
OK, but the filesystem client would need to support write_begin/write_end in order for writes to do multi-seg iovecs. nfsd of course will also be fixed by the earlier patch I referenced, but you did want userspace multi-seg writes to work too... > > OTOH, this is very likely to go upstream, so your filesystem will need to > > be ported over sooner or later anyway. > > Lustre copies the ext3 source from the kernel, patches in some extra > features and renames them during build. So one the one hand it always > breaks whenever someone meddles with the ext3 code. On the other hand > improvement for ext3 get picked up by lustre semi automatically. > > In this case lustre would get the begin_write() function from ext3 and > use it. OK. Yes ext3 is converted in -mm. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
