Messages in this thread | | | Date | Fri, 4 Apr 2003 19:22:01 -0800 | From | Andrew Morton <> | Subject | Re: objrmap and vmtruncate |
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"Martin J. Bligh" <mbligh@aracnet.com> wrote: > > > objrmap does not seem to help. Page clustering might, but is unlikely to > > be enabled on the machines which actually care about the overhead. > > eh? Not sure what you mean by that. It helped massively ... > diffprofile from kernbench showed: > > -4666 -74.9% page_add_rmap > -10666 -92.0% page_remove_rmap > > I'd say that about an 85% reduction in cost is pretty damned fine ;-) > And that was about a 20% overall reduction in the system time for the > test too ... that was all for partial objrmap (file backed, not anon). >
In the test I use (my patch management scripts, which is basically bash forking its brains out) objrmap reclaims only 30-50% of the rmap CPU overhead.
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