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| author | Mel Gorman <mgorman@suse.de> | 2013-10-07 11:29:05 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-10-09 12:40:32 +0200 |
| commit | 1bc115d87dffd1c43bdc3c9c9d1e3a51c195d18e (patch) | |
| tree | 56a26b4f4fe089e3dd1df5a26877d1e4c0114d35 /mm/mprotect.c | |
| parent | 9ff1d9ff3c2c8ab3feaeb2e8056a07ca293f7bde (diff) | |
| download | op-kernel-dev-1bc115d87dffd1c43bdc3c9c9d1e3a51c195d18e.zip op-kernel-dev-1bc115d87dffd1c43bdc3c9c9d1e3a51c195d18e.tar.gz | |
mm: numa: Scan pages with elevated page_mapcount
Currently automatic NUMA balancing is unable to distinguish between false
shared versus private pages except by ignoring pages with an elevated
page_mapcount entirely. This avoids shared pages bouncing between the
nodes whose task is using them but that is ignored quite a lot of data.
This patch kicks away the training wheels in preparation for adding support
for identifying shared/private pages is now in place. The ordering is so
that the impact of the shared/private detection can be easily measured. Note
that the patch does not migrate shared, file-backed within vmas marked
VM_EXEC as these are generally shared library pages. Migrating such pages
is not beneficial as there is an expectation they are read-shared between
caches and iTLB and iCache pressure is generally low.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-28-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'mm/mprotect.c')
| -rw-r--r-- | mm/mprotect.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/mm/mprotect.c b/mm/mprotect.c index 2da33dc..41e0292 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -69,9 +69,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, if (last_nid != this_nid) all_same_node = false; - /* only check non-shared pages */ - if (!pte_numa(oldpte) && - page_mapcount(page) == 1) { + if (!pte_numa(oldpte)) { ptent = pte_mknuma(ptent); updated = true; } |
