Kevin, On Wed, Jul 11, 2007 at 05:28:01PM -0500, Kevin Corry wrote: > Hi, > > I happened to be reading through the kernel routine __pfm_ctxswout_thread() > in > perfmon/perfmon_ctxsw.c and noticed that the > if (need_save_pmds) > pfm_save_pmds(ctx, set); > is inside the "#ifdef CONFIG_SMP". It seems like that should be outside > the "#ifdef CONFIG_SMP". Can we really assume that the counters do not need > to be saved on a UP system? Or is it implicitly assuming that the > pfm_arch_ctxswout_thread() call will have saved the PMDs in that case? If so, > I don't think that the PowerPC code is handling that correctly. Any thoughts? > In UP mode, we use a lazy save/restore approach. On ctxswout, we stop monitoring but we do not save, hoping we'll find our state back next time around. In case of conflict, the old state is saved by the newcomer. AFAIK, there should not be any need for arch-specific code for this.
-- -Stephane _______________________________________________ perfmon mailing list [email protected] http://www.hpl.hp.com/hosted/linux/mail-archives/perfmon/
