tmpfs: move swap_state stats update
Both unionfs and memcgroups pose challenges to tmpfs and shmem. To help fix,
it's best to move the swap swizzling functions from swap_state.c to shmem.c.
As a preliminary to that, move swap stats updating down into
__add_to_swap_cache, which will remain internal to swap_state.c.
Well, actually, just move down the incrementation of add_total: remove
noent_race and exist_race completely, they are relics of my 2.4.11 testing.
Alt-SysRq-m users will be thrilled if 2.6.25 is at last free of "race M+N"s.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/swap_state.c b/mm/swap_state.c
index e787564..18fce36 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -52,16 +52,13 @@
unsigned long del_total;
unsigned long find_success;
unsigned long find_total;
- unsigned long noent_race;
- unsigned long exist_race;
} swap_cache_info;
void show_swap_cache_info(void)
{
- printk("Swap cache: add %lu, delete %lu, find %lu/%lu, race %lu+%lu\n",
+ printk("Swap cache: add %lu, delete %lu, find %lu/%lu\n",
swap_cache_info.add_total, swap_cache_info.del_total,
- swap_cache_info.find_success, swap_cache_info.find_total,
- swap_cache_info.noent_race, swap_cache_info.exist_race);
+ swap_cache_info.find_success, swap_cache_info.find_total);
printk("Free swap = %lukB\n", nr_swap_pages << (PAGE_SHIFT - 10));
printk("Total swap = %lukB\n", total_swap_pages << (PAGE_SHIFT - 10));
}
@@ -89,6 +86,7 @@
set_page_private(page, entry.val);
total_swapcache_pages++;
__inc_zone_page_state(page, NR_FILE_PAGES);
+ INC_CACHE_INFO(add_total);
}
write_unlock_irq(&swapper_space.tree_lock);
radix_tree_preload_end();
@@ -102,10 +100,9 @@
int error;
BUG_ON(PageLocked(page));
- if (!swap_duplicate(entry)) {
- INC_CACHE_INFO(noent_race);
+ if (!swap_duplicate(entry))
return -ENOENT;
- }
+
SetPageLocked(page);
error = __add_to_swap_cache(page, entry, gfp_mask & GFP_KERNEL);
/*
@@ -114,11 +111,8 @@
if (error) {
ClearPageLocked(page);
swap_free(entry);
- if (error == -EEXIST)
- INC_CACHE_INFO(exist_race);
return error;
}
- INC_CACHE_INFO(add_total);
return 0;
}
@@ -178,11 +172,9 @@
case 0: /* Success */
SetPageUptodate(page);
SetPageDirty(page);
- INC_CACHE_INFO(add_total);
return 1;
case -EEXIST:
/* Raced with "speculative" read_swap_cache_async */
- INC_CACHE_INFO(exist_race);
swap_free(entry);
continue;
default:
@@ -225,9 +217,7 @@
if (!swap_duplicate(entry))
BUG();
SetPageDirty(page);
- INC_CACHE_INFO(add_total);
- } else if (err == -EEXIST)
- INC_CACHE_INFO(exist_race);
+ }
return err;
}