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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2016-01-15 16:52:39 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-15 17:56:32 -0800
commitb1caa957ae6da3142a73ba8c5c9b2ca821021f0f (patch)
treedce0064717ceef30c5d6c3c555ccbdf4339bd5a8
parent7479df6da9506a624ae214588269ed42221494f9 (diff)
downloadop-kernel-dev-b1caa957ae6da3142a73ba8c5c9b2ca821021f0f.zip
op-kernel-dev-b1caa957ae6da3142a73ba8c5c9b2ca821021f0f.tar.gz
khugepaged: ignore pmd tables with THP mapped with ptes
Prepare khugepaged to see compound pages mapped with pte. For now we won't collapse the pmd table with such pte. khugepaged is subject for future rework wrt new refcounting. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Jerome Marchand <jmarchan@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/trace/events/huge_memory.h1
-rw-r--r--mm/huge_memory.c9
2 files changed, 9 insertions, 1 deletions
diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h
index 97d635c..0f803d2 100644
--- a/include/trace/events/huge_memory.h
+++ b/include/trace/events/huge_memory.h
@@ -22,6 +22,7 @@
EM( SCAN_PAGE_LRU, "page_not_in_lru") \
EM( SCAN_PAGE_LOCK, "page_locked") \
EM( SCAN_PAGE_ANON, "page_not_anon") \
+ EM( SCAN_PAGE_COMPOUND, "page_compound") \
EM( SCAN_ANY_PROCESS, "no_process_for_page") \
EM( SCAN_VMA_NULL, "vma_null") \
EM( SCAN_VMA_CHECK, "vma_check_failed") \
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b3cc9f2..f4da89c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -45,6 +45,7 @@ enum scan_result {
SCAN_PAGE_LRU,
SCAN_PAGE_LOCK,
SCAN_PAGE_ANON,
+ SCAN_PAGE_COMPOUND,
SCAN_ANY_PROCESS,
SCAN_VMA_NULL,
SCAN_VMA_CHECK,
@@ -2770,6 +2771,13 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
result = SCAN_PAGE_NULL;
goto out_unmap;
}
+
+ /* TODO: teach khugepaged to collapse THP mapped with pte */
+ if (PageCompound(page)) {
+ result = SCAN_PAGE_COMPOUND;
+ goto out_unmap;
+ }
+
/*
* Record which node the original page is from and save this
* information to khugepaged_node_load[].
@@ -2782,7 +2790,6 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
goto out_unmap;
}
khugepaged_node_load[node]++;
- VM_BUG_ON_PAGE(PageCompound(page), page);
if (!PageLRU(page)) {
result = SCAN_SCAN_ABORT;
goto out_unmap;
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