* Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Wed, 17 Jul 2013 09:21:00 +0200 Ingo Molnar <mingo@xxxxxxxxxx> wrote: > > > > > * Dave Hansen <dave@xxxxxxxx> wrote: > > > > > I was investigating some TLB flush scaling issues and realized > > > that we do not have any good methods for figuring out how many > > > TLB flushes we are doing. > > > > > > It would be nice to be able to do these in generic code, but the > > > arch-independent calls don't explicitly specify whether we > > > actually need to do remote flushes or not. In the end, we really > > > need to know if we actually _did_ global vs. local invalidations, > > > so that leaves us with few options other than to muck with the > > > counters from arch-specific code. > > Spose so, if you really think it's worth it. It's all downside for > uniprocessor machines. [...] UP is slowly going extinct, but in any case these counters ought to inform us about TLB flushes even on UP systems: > > > + NR_TLB_LOCAL_FLUSH_ALL, > > > + NR_TLB_LOCAL_FLUSH_ONE, > > > + NR_TLB_LOCAL_FLUSH_ONE_KERNEL, While these ought to be compiled out on UP kernels: > > > + NR_TLB_REMOTE_FLUSH, /* cpu tried to flush others' tlbs */ > > > + NR_TLB_REMOTE_FLUSH_RECEIVED,/* cpu received ipi for flush */ Right? > > Please fix the vertical alignment of comments. > > I looked - this isn't practical. > > It would be nice to actually document these things though. We don't > *have* to squeeze the comment into the RHS. Agreed. Thanks, Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>