On Wed, Mar 17, 2010 at 05:20:53PM +1100, Nick Piggin wrote:
> btrfs: use add_to_page_cache_lru, use __page_cache_alloc
>
> Pagecache pages should be allocated with __page_cache_alloc, so they
> obey pagecache memory policies.
>
> add_to_page_cache_lru is exported, so it should be used. Benefits over
> using a private pagevec: neater code, 128 bytes fewer stack used, percpu
> lru ordering is preserved, and finally don't need to flush pagevec
> before returning so batching may be shared with other LRU insertions.
>
> Signed-off-by: Nick Piggin <npiggin@xxxxxxx>:
Missed a rediff.
---
fs/btrfs/compression.c | 20 ++------------------
fs/btrfs/extent_io.c | 22 +++++-----------------
2 files changed, 7 insertions(+), 35 deletions(-)
Index: linux-2.6/fs/btrfs/compression.c
===================================================================
--- linux-2.6.orig/fs/btrfs/compression.c
+++ linux-2.6/fs/btrfs/compression.c
@@ -31,7 +31,6 @@
#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/bit_spinlock.h>
-#include <linux/pagevec.h>
#include "compat.h"
#include "ctree.h"
#include "disk-io.h"
@@ -445,7 +444,6 @@ static noinline int add_ra_bio_pages(str
unsigned long nr_pages = 0;
struct extent_map *em;
struct address_space *mapping = inode->i_mapping;
- struct pagevec pvec;
struct extent_map_tree *em_tree;
struct extent_io_tree *tree;
u64 end;
@@ -461,7 +459,6 @@ static noinline int add_ra_bio_pages(str
end_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
- pagevec_init(&pvec, 0);
while (last_offset < compressed_end) {
page_index = last_offset >> PAGE_CACHE_SHIFT;
@@ -478,26 +475,17 @@ static noinline int add_ra_bio_pages(str
goto next;
}
- page = alloc_page(mapping_gfp_mask(mapping) & ~__GFP_FS);
+ page = __page_cache_alloc(mapping_gfp_mask(mapping) &
+ ~__GFP_FS);
if (!page)
break;
- page->index = page_index;
- /*
- * what we want to do here is call add_to_page_cache_lru,
- * but that isn't exported, so we reproduce it here
- */
- if (add_to_page_cache(page, mapping,
- page->index, GFP_NOFS)) {
+ if (add_to_page_cache_lru(page, mapping, page_index,
+ GFP_NOFS)) {
page_cache_release(page);
goto next;
}
- /* open coding of lru_cache_add, also not exported */
- page_cache_get(page);
- if (!pagevec_add(&pvec, page))
- __pagevec_lru_add_file(&pvec);
-
end = last_offset + PAGE_CACHE_SIZE - 1;
/*
* at this point, we have a locked page in the page cache
@@ -551,8 +539,6 @@ static noinline int add_ra_bio_pages(str
next:
last_offset += PAGE_CACHE_SIZE;
}
- if (pagevec_count(&pvec))
- __pagevec_lru_add_file(&pvec);
return 0;
}
Index: linux-2.6/fs/btrfs/extent_io.c
===================================================================
--- linux-2.6.orig/fs/btrfs/extent_io.c
+++ linux-2.6/fs/btrfs/extent_io.c
@@ -2663,33 +2663,21 @@ int extent_readpages(struct extent_io_tr
{
struct bio *bio = NULL;
unsigned page_idx;
- struct pagevec pvec;
unsigned long bio_flags = 0;
- pagevec_init(&pvec, 0);
for (page_idx = 0; page_idx < nr_pages; page_idx++) {
struct page *page = list_entry(pages->prev, struct page, lru);
prefetchw(&page->flags);
list_del(&page->lru);
- /*
- * what we want to do here is call add_to_page_cache_lru,
- * but that isn't exported, so we reproduce it here
- */
- if (!add_to_page_cache(page, mapping,
+ if (add_to_page_cache_lru(page, mapping,
page->index, GFP_KERNEL)) {
-
- /* open coding of lru_cache_add, also not exported */
- page_cache_get(page);
- if (!pagevec_add(&pvec, page))
- __pagevec_lru_add_file(&pvec);
- __extent_read_full_page(tree, page, get_extent,
- &bio, 0, &bio_flags);
+ page_cache_release(page);
+ continue;
}
- page_cache_release(page);
+ __extent_read_full_page(tree, page, get_extent,
+ &bio, 0, &bio_flags);
}
- if (pagevec_count(&pvec))
- __pagevec_lru_add_file(&pvec);
BUG_ON(!list_empty(pages));
if (bio)
submit_one_bio(READ, bio, 0, bio_flags);
--
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