On Fri, Jun 05, 2009 at 09:57:19AM -0400, Steve Dickson wrote: > > > Trond Myklebust wrote: > > On Fri, 2009-06-05 at 09:30 -0400, Steve Dickson wrote: > >> Tom Talpey wrote: > >>> On 6/5/2009 7:35 AM, Steve Dickson wrote: > >>>> Brian R Cowan wrote: > >>>>> Trond Myklebust<trond.myklebust@xxxxxxxxxx> wrote on 06/04/2009 > >>>>> 02:04:58 > >>>>> PM: > >>>>> > >>>>>> Did you try turning off write gathering on the server (i.e. add the > >>>>>> 'no_wdelay' export option)? As I said earlier, that forces a delay of > >>>>>> 10ms per RPC call, which might explain the FILE_SYNC slowness. > >>>>> Just tried it, this seems to be a very useful workaround as well. The > >>>>> FILE_SYNC write calls come back in about the same amount of time as the > >>>>> write+commit pairs... Speeds up building regardless of the network > >>>>> filesystem (ClearCase MVFS or straight NFS). > >>>> Does anybody had the history as to why 'no_wdelay' is an > >>>> export default? > >>> Because "wdelay" is a complete crock? > >>> > >>> Adding 10ms to every write RPC only helps if there's a steady > >>> single-file stream arriving at the server. In most other workloads > >>> it only slows things down. > >>> > >>> The better solution is to continue tuning the clients to issue > >>> writes in a more sequential and less all-or-nothing fashion. > >>> There are plenty of other less crock-ful things to do in the > >>> server, too. > >> Ok... So do you think removing it as a default would cause > >> any regressions? > > > > It might for NFSv2 clients, since they don't have the option of using > > unstable writes. I'd therefore prefer a kernel solution that makes write > > gathering an NFSv2 only feature. > Sounds good to me! ;-) Patch welcomed.--b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
