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authorPeter Xu <peterx@redhat.com>2020-04-07 06:06:04 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-07 20:43:39 +0300
commite1e267c7928fe387e5e1cffeafb0de2d0473663a (patch)
tree56afcda13ad17fb3efbce5f35d78bd801006e76a /include
parentf45ec5ff16a75f96dac8c89862d75f1d8739efd4 (diff)
downloadlinux-e1e267c7928fe387e5e1cffeafb0de2d0473663a.tar.xz
khugepaged: skip collapse if uffd-wp detected
Don't collapse the huge PMD if there is any userfault write protected small PTEs. The problem is that the write protection is in small page granularity and there's no way to keep all these write protection information if the small pages are going to be merged into a huge PMD. The same thing needs to be considered for swap entries and migration entries. So do the check as well disregarding khugepaged_max_ptes_swap. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Jerome Glisse <jglisse@redhat.com> Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Bobby Powers <bobbypowers@gmail.com> Cc: Brian Geffon <bgeffon@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Denis Plotnikov <dplotnikov@virtuozzo.com> Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Martin Cracauer <cracauer@cons.org> Cc: Marty McFadden <mcfadden8@llnl.gov> Cc: Maya Gokhale <gokhale2@llnl.gov> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shli@fb.com> Link: http://lkml.kernel.org/r/20200220163112.11409-12-peterx@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/trace/events/huge_memory.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h
index d82a0f4e824d..70e32ff096ec 100644
--- a/include/trace/events/huge_memory.h
+++ b/include/trace/events/huge_memory.h
@@ -13,6 +13,7 @@
EM( SCAN_PMD_NULL, "pmd_null") \
EM( SCAN_EXCEED_NONE_PTE, "exceed_none_pte") \
EM( SCAN_PTE_NON_PRESENT, "pte_non_present") \
+ EM( SCAN_PTE_UFFD_WP, "pte_uffd_wp") \
EM( SCAN_PAGE_RO, "no_writable_page") \
EM( SCAN_LACK_REFERENCED_PAGE, "lack_referenced_page") \
EM( SCAN_PAGE_NULL, "page_null") \