The patch titled
md/bitmap: remove unnecessary page reference manipulations from md/bitmap code
has been added to the -mm tree. Its filename is
md-bitmap-remove-unnecessary-page-reference-manipulations-from-md-bitmap-code.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
From: NeilBrown <neilb@xxxxxxx>
md/bitmap gets a collection of pages representing the bitmap when it
initialises the bitmap, and puts all the references when discarding the
bitmap.
It also occasionally takes extra references without any good reason, and
sometimes drops them ... though it doesn't always drop them, which can result
in a memory leak.
This patch removes the unnecessary 'get_page' calls, and the corresponding
'put_page' calls.
Signed-off-by: Neil Brown <neilb@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/md/bitmap.c | 20 ++------------------
1 files changed, 2 insertions(+), 18 deletions(-)
diff -puN drivers/md/bitmap.c~md-bitmap-remove-unnecessary-page-reference-manipulations-from-md-bitmap-code drivers/md/bitmap.c
--- 25/drivers/md/bitmap.c~md-bitmap-remove-unnecessary-page-reference-manipulations-from-md-bitmap-code Fri May 12 10:24:46 2006
+++ 25-akpm/drivers/md/bitmap.c Fri May 12 10:24:46 2006
@@ -332,7 +332,6 @@ static int write_page(struct bitmap *bit
/* add to list to be waited for */
struct page_list *item = mempool_alloc(bitmap->write_pool, GFP_NOIO);
item->page = page;
- get_page(page);
spin_lock(&bitmap->write_lock);
list_add(&item->list, &bitmap->complete_pages);
spin_unlock(&bitmap->write_lock);
@@ -548,7 +547,6 @@ static void bitmap_mask_state(struct bit
spin_unlock_irqrestore(&bitmap->lock, flags);
return;
}
- get_page(bitmap->sb_page);
spin_unlock_irqrestore(&bitmap->lock, flags);
sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
switch (op) {
@@ -559,7 +557,6 @@ static void bitmap_mask_state(struct bit
default: BUG();
}
kunmap_atomic(sb, KM_USER0);
- put_page(bitmap->sb_page);
}
/*
@@ -641,7 +638,6 @@ static void drain_write_queues(struct bi
while ((item = dequeue_page(bitmap))) {
/* don't bother to wait */
- put_page(item->page);
mempool_free(item, bitmap->write_pool);
}
}
@@ -744,11 +740,6 @@ static void bitmap_file_set_bit(struct b
page = filemap_get_page(bitmap, chunk);
bit = file_page_offset(chunk);
-
- /* make sure the page stays cached until it gets written out */
- if (! test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY))
- get_page(page);
-
/* set the bit */
kaddr = kmap_atomic(page, KM_USER0);
if (bitmap->flags & BITMAP_HOSTENDIAN)
@@ -1028,10 +1019,9 @@ int bitmap_daemon_work(struct bitmap *bi
if (!test_page_attr(bitmap, page, BITMAP_PAGE_CLEAN)) {
int need_write = test_page_attr(bitmap, page,
BITMAP_PAGE_NEEDWRITE);
- if (need_write) {
- get_page(page);
+ if (need_write)
clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
- }
+
spin_unlock_irqrestore(&bitmap->lock, flags);
if (need_write) {
switch (write_page(bitmap, page, 0)) {
@@ -1043,13 +1033,11 @@ int bitmap_daemon_work(struct bitmap *bi
default:
bitmap_file_kick(bitmap);
}
- put_page(page);
}
continue;
}
/* grab the new page, sync and release the old */
- get_page(page);
if (lastpage != NULL) {
if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
@@ -1063,7 +1051,6 @@ int bitmap_daemon_work(struct bitmap *bi
set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
spin_unlock_irqrestore(&bitmap->lock, flags);
}
- put_page(lastpage);
if (err)
bitmap_file_kick(bitmap);
} else
@@ -1117,8 +1104,6 @@ int bitmap_daemon_work(struct bitmap *bi
set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
spin_unlock_irqrestore(&bitmap->lock, flags);
}
-
- put_page(lastpage);
}
return err;
@@ -1140,7 +1125,6 @@ static void bitmap_writeback(struct bitm
PRINTK("finished page writeback: %p\n", page);
err = PageError(page);
- put_page(page);
if (err) {
printk(KERN_WARNING "%s: bitmap file writeback "
"failed (page %lu): %d\n",
_
Patches currently in -mm which might be from neilb@xxxxxxx are
origin.patch
fix-dcache-race-during-umount.patch
fix-dcache-race-during-umount-fix.patch
prune_one_dentry-tweaks.patch
remove-softlockup-from-invalidate_mapping_pages.patch
kconfig-select-things-at-the-closest-tristate-instead-of-bool.patch
make-address_space_operations-invalidatepage-return-void-reiser4.patch
md-reformat-code-in-raid1_end_write_request-to-avoid-goto.patch
md-remove-arbitrary-limit-on-chunk-size.patch
md-remove-useless-ioctl-warning.patch
md-increase-the-delay-before-marking-metadata-clean-and-make-it-configurable.patch
md-merge-raid5-and-raid6-code.patch
md-remove-nuisance-message-at-shutdown.patch
md-allow-checkpoint-of-recovery-with-version-1-superblock.patch
md-allow-a-linear-array-to-have-drives-added-while-active.patch
md-support-stripe-offset-mode-in-raid10.patch
md-make-md_print_devices-static.patch
md-split-reshape-portion-of-raid5-sync_request-into-a-separate-function.patch
md-bitmap-fix-online-removal-of-file-backed-bitmaps.patch
md-bitmap-remove-bitmap-writeback-daemon.patch
md-bitmap-cleaner-separation-of-page-attribute-handlers-in-md-bitmap.patch
md-bitmap-use-set_bit-etc-for-bitmap-page-attributes.patch
md-bitmap-remove-unnecessary-page-reference-manipulations-from-md-bitmap-code.patch
md-bitmap-remove-dead-code-from-md-bitmap.patch
md-bitmap-tidy-up-i_writecount-handling-in-md-bitmap.patch
md-bitmap-change-md-bitmap-file-handling-to-use-bmap-to-file-blocks.patch
md-dm-reduce-stack-usage-with-stacked-block-devices.patch
-
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