Re: [PATCH 00 of 41] Transparent Hugepage Support #17

On Tue, 6 Apr 2010, Andrea Arcangeli wrote:
>
> In short I first measured the page fault improvement in host (~+50%
> faster, sure that has nothing to do with pmd_huge or the tlb miss, I
> said I mentioned it just for curiosity in fact), then measured the tlb
> miss improvement in host (a few percent faster as usual with
> hugetlbfs) then measured the boost in guest if host uses hugepages
> (with no guest kernel change at all, just the tlb miss going faster in
> guest and that boosts the guest kernel compile 6%) and then some other
> test with dd with all combinations of host/guest using hugepages or
> not, and also with dd run on bare metal with or without hugepages.

Yeah, sorry. I misread your email - I noticed that 6% improvement for 
something that looked like a workload I might actually _care_ about, and 
didn't track the context enough to notice that it was just for the "host 
is using hugepages" case.

So I thought it was a more interesting load than it was. The 
virtualization "TLB miss is expensive" load I can't find it in myself to 
care about. "Get a better CPU" is my answer to that one,

			Linus

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>