The patch titled
mm: write_cache_pages terminate quickly
has been added to the -mm tree. Its filename is
mm-write_cache_pages-terminate-quickly.patch
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------------------------------------------------------
Subject: mm: write_cache_pages terminate quickly
From: Nick Piggin <npiggin@xxxxxxx>
Terminate the write_cache_pages loop upon encountering the first page past
end, without locking the page. Pages cannot have their index change when
we have a reference on them (truncate, eg truncate_inode_pages_range
performs the same check without the page lock).
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
Cc: Chris Mason <chris.mason@xxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: jim owens <jowens@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page-writeback.c | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)
diff -puN mm/page-writeback.c~mm-write_cache_pages-terminate-quickly mm/page-writeback.c
--- a/mm/page-writeback.c~mm-write_cache_pages-terminate-quickly
+++ a/mm/page-writeback.c
@@ -911,15 +911,24 @@ retry:
for (i = 0; i < nr_pages; i++) {
struct page *page = pvec.pages[i];
- done_index = page->index + 1;
-
/*
- * At this point we hold neither mapping->tree_lock nor
- * lock on the page itself: the page may be truncated or
- * invalidated (changing page->mapping to NULL), or even
- * swizzled back from swapper_space to tmpfs file
- * mapping
+ * At this point, the page may be truncated or
+ * invalidated (changing page->mapping to NULL), or
+ * even swizzled back from swapper_space to tmpfs file
+ * mapping. However, page->index will not change
+ * because we have a reference on the page.
*/
+ if (page->index > end) {
+ /*
+ * can't be range_cyclic (1st pass) because
+ * end == -1 in that case.
+ */
+ done = 1;
+ break;
+ }
+
+ done_index = page->index + 1;
+
lock_page(page);
/*
@@ -936,15 +945,6 @@ continue_unlock:
continue;
}
- if (page->index > end) {
- /*
- * can't be range_cyclic (1st pass) because
- * end == -1 in that case.
- */
- done = 1;
- goto continue_unlock;
- }
-
if (!PageDirty(page)) {
/* someone wrote it for us */
goto continue_unlock;
_
Patches currently in -mm which might be from npiggin@xxxxxxx are
mm-increase-the-default-mlock-limit-from-32k-to-64k.patch
fs-remove-prepare_write-commit_write.patch
linux-next.patch
mm-dont-mark_page_accessed-in-fault-path.patch
mm-invoke-oom-killer-from-page-fault.patch
mm-invoke-oom-killer-from-page-fault-fix.patch
mm-invoke-oom-killer-from-page-fault-fix-fix-2.patch
mm-write_cache_pages-cyclic-fix.patch
mm-write_cache_pages-cyclic-fix-fix.patch
mm-write_cache_pages-early-loop-termination.patch
mm-write_cache_pages-writepage-error-fix.patch
mm-write_cache_pages-integrity-fix.patch
mm-write_cache_pages-cleanups.patch
mm-write_cache_pages-optimise-page-cleaning.patch
mm-write_cache_pages-terminate-quickly.patch
mm-write_cache_pages-more-terminate-quickly.patch
mm-do_sync_mapping_range-integrity-fix.patch
reiser4.patch
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