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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2016-01-16 03:54:00 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-16 04:56:32 +0300
commit4d2fa965483f4c39bd097ff9bbf3efe62d4cf367 (patch)
treed885a08dddf9a93e755ae02be7a4a3e012c09cd2 /mm
parentba98828088ad3ffa7ee4d5b017c291934fcbaeb9 (diff)
downloadlinux-4d2fa965483f4c39bd097ff9bbf3efe62d4cf367.tar.xz
thp, mm: split_huge_page(): caller need to lock page
We're going to use migration entries instead of compound_lock() to stabilize page refcounts. Setup and remove migration entries require page to be locked. Some of split_huge_page() callers already have the page locked. Let's require everybody to lock the page before calling split_huge_page(). 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: Vlastimil Babka <vbabka@suse.cz> Acked-by: Jerome Marchand <jmarchan@redhat.com> 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>
Diffstat (limited to 'mm')
-rw-r--r--mm/memory-failure.c8
-rw-r--r--mm/migrate.c8
2 files changed, 13 insertions, 3 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 5b965e27aaae..a2c987df80eb 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1149,7 +1149,9 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
}
if (!PageHuge(p) && PageTransHuge(hpage)) {
+ lock_page(hpage);
if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
+ unlock_page(hpage);
if (!PageAnon(hpage))
pr_err("MCE: %#lx: non anonymous thp\n", pfn);
else
@@ -1159,6 +1161,7 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
put_hwpoison_page(p);
return -EBUSY;
}
+ unlock_page(hpage);
VM_BUG_ON_PAGE(!page_count(p), p);
hpage = compound_head(p);
}
@@ -1751,7 +1754,10 @@ int soft_offline_page(struct page *page, int flags)
return -EBUSY;
}
if (!PageHuge(page) && PageTransHuge(hpage)) {
- if (PageAnon(hpage) && unlikely(split_huge_page(hpage))) {
+ lock_page(page);
+ ret = split_huge_page(hpage);
+ unlock_page(page);
+ if (unlikely(ret)) {
pr_info("soft offline: %#lx: failed to split THP\n",
pfn);
if (flags & MF_COUNT_INCREASED)
diff --git a/mm/migrate.c b/mm/migrate.c
index 91545da23fd1..dec81a9e2fd6 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -943,9 +943,13 @@ static ICE_noinline int unmap_and_move(new_page_t get_new_page,
goto out;
}
- if (unlikely(PageTransHuge(page)))
- if (unlikely(split_huge_page(page)))
+ if (unlikely(PageTransHuge(page))) {
+ lock_page(page);
+ rc = split_huge_page(page);
+ unlock_page(page);
+ if (rc)
goto out;
+ }
rc = __unmap_and_move(page, newpage, force, mode);
if (rc == MIGRATEPAGE_SUCCESS)