Re: [PATCH 1/4] x86_64: (SPARSE_VIRTUAL doubles sparsemem speed)

Christoph Lameter
2007-04-09T17:16:10Z

On Mon, 9 Apr 2007, William Lee Irwin III wrote:

> Whatever's going on with the rest of this, I really like this
> instrumentation patch. It may be worthwhile to allow pc_start() to be
> overridden so things like performance counter MSR's are usable, but
> the framework looks very useful.

Yeah. I also did some measurements on quicklists on x86_64 and it seems
that caching page table pages is also useful:

no quicklist

pte_alloc 1569048 4.3s(401ns/2.7us/179.7us)
pmd_alloc 780988 2.1s(337ns/2.7us/86.1us)
pud_alloc 780072 2.2s(424ns/2.8us/300.6us)
pgd_alloc 260022 1s(920ns/4us/263.1us)

quicklist:

pte_alloc 452436 573.4ms(8ns/1.3us/121.1us)
pmd_alloc 196204 174.5ms(7ns/889ns/46.1us)
pud_alloc 195688 172.4ms(7ns/881ns/151.3us)
pgd_alloc 65228 9.8ms(8ns/150ns/6.1us)