On Wed, 9 May 2007 16:10:05 -0700 "Yu, Fenghua" <[EMAIL PROTECTED]> wrote:
> > > On Wed, 9 May 2007, Andrew Morton wrote: > > >> erm, it's not obviosu from all this that the patches are worth > proceeding > >> with, are they? > > >What was it? 0.5% performance improvement on a synthetic benchmark? > >Process wakeup I believe? > > The initial patch and discussion is from: > http://www.uwsg.iu.edu/hypermail/linux/kernel/0704.1/0340.html > > Yes, the runqueue patch has a 0.5% perf improvement on database > workload(which is a good improvement for this workload). > > The theory behind the patches is: > > 1. Minimize number of cache lines that are touched during a remote > access. On Numa system, remote access is more expensive than local. > 2. Do not share cache line between remote accessed data and local > accessed data. Local data update may cause remote access cache miss and > wait for longer time. > > Although the patches themselves don't save or waste per_cpu size, the > above two reasons are good to have them in. > Guys, this is all a lesson in the value of changelogs, and in how not to write them. Can you please prepare a new changelog for these patches? Something which encapsulates all the above in as brief a form as possible and which includes some numbers describing the space and/or speed improvements? Thanks. - 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/
