Make sure the contention for the token happens _before_ any read-in and
kicks the swap-token algo only when the VM is under pressure.
Signed-off-by: Ashwin Chaugule <ashwin.chaugule@celunite.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* effect.
*/
error = page_cache_read(file, pgoff);
- grab_swap_token();
/*
* The page we want has now been added to the page cache.
delayacct_set_flag(DELAYACCT_PF_SWAPIN);
page = lookup_swap_cache(entry);
if (!page) {
+ grab_swap_token(); /* Contend for token _before_ read-in */
swapin_readahead(entry, address, vma);
page = read_swap_cache_async(entry, vma, address);
if (!page) {
/* Had to read the page from swap area: Major fault */
ret = VM_FAULT_MAJOR;
count_vm_event(PGMAJFAULT);
- grab_swap_token();
}
delayacct_clear_flag(DELAYACCT_PF_SWAPIN);