The patch titled
AOP_TRUNCATED_PAGE victims in read_pages() belong in the LRU
has been added to the -mm tree. Its filename is
aop_truncated_page-victims-in-read_pages-belong-in-the-lru.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
From: Zach Brown <zach.brown@xxxxxxxxxx>
AOP_TRUNCATED_PAGE victims in read_pages() belong in the LRU
Nick Piggin rightly pointed out that the introduction of AOP_TRUNCATED_PAGE
to read_pages() was wrong to leave A_T_P victim pages in the page cache but
not put them in the LRU. Failing to do so hid them from the VM.
A_T_P just means that the aop method unlocked the page rather than
performing IO. It would be very rare that the page was truncated between
the unlock and testing A_T_P. So we leave the pages in the LRU for likely
reuse soon rather than backing them back out of the page cache. We do this
by matching the behaviour before the A_T_P introduction which added pages
to the LRU regardless of what ->readpage() did.
This doesn't include the unrelated cleanup in Nick's initial fix which
changed read_pages() to return void to match its only caller's behaviour of
ignoring errors.
Signed-off-by: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Signed-off-by: Zach Brown <zach.brown@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/readahead.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff -puN mm/readahead.c~aop_truncated_page-victims-in-read_pages-belong-in-the-lru mm/readahead.c
--- devel/mm/readahead.c~aop_truncated_page-victims-in-read_pages-belong-in-the-lru 2006-05-03 19:16:00.000000000 -0700
+++ devel-akpm/mm/readahead.c 2006-05-03 19:16:00.000000000 -0700
@@ -182,14 +182,11 @@ static int read_pages(struct address_spa
list_del(&page->lru);
if (!add_to_page_cache(page, mapping,
page->index, GFP_KERNEL)) {
- ret = mapping->a_ops->readpage(filp, page);
- if (ret != AOP_TRUNCATED_PAGE) {
- if (!pagevec_add(&lru_pvec, page))
- __pagevec_lru_add(&lru_pvec);
- continue;
- } /* else fall through to release */
- }
- page_cache_release(page);
+ mapping->a_ops->readpage(filp, page);
+ if (!pagevec_add(&lru_pvec, page))
+ __pagevec_lru_add(&lru_pvec);
+ } else
+ page_cache_release(page);
}
pagevec_lru_add(&lru_pvec);
ret = 0;
_
Patches currently in -mm which might be from zach.brown@xxxxxxxxxx are
git-ocfs2.patch
git-scsi-rc-fixes.patch
aop_truncated_page-victims-in-read_pages-belong-in-the-lru.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
