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| author | John Dykstra <jdykstra@cray.com> | 2012-05-25 21:12:46 (GMT) |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2012-05-30 08:57:11 (GMT) |
| commit | fa83523f45fbb403eba4ebc5704bf98aa4da0163 (patch) | |
| tree | 35466e5e2e9e5ed8171ef596d63690ed42621fca /arch/cris | |
| parent | 1b38a3a10f2ad96a3c0130f63b7f3610bab7090d (diff) | |
| download | linux-fa83523f45fbb403eba4ebc5704bf98aa4da0163.tar.xz | |
x86/mm/pat: Improve scaling of pat_pagerange_is_ram()
Function pat_pagerange_is_ram() scales poorly to large address
ranges, because it probes the resource tree for each page.
On a 2.6 GHz Opteron, this function consumes 34 ms for a 1 GB range.
It is called twice during untrack_pfn_vma(), slowing process
cleanup and handicapping the OOM killer.
This replacement consumes less than 1ms, under the same conditions.
Signed-off-by: John Dykstra <jdykstra@cray.com> on behalf of Cray Inc.
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1337980366.1979.6.camel@redwood
[ Small stylistic cleanups and renames ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/cris')
0 files changed, 0 insertions, 0 deletions