diff options
Diffstat (limited to 'mm/swapfile.c')
| -rw-r--r-- | mm/swapfile.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index 2b8d9c3fbb47..bf4ef2e40f23 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2023,7 +2023,6 @@ static unsigned int find_next_to_unuse(struct swap_info_struct *si, * If the boolean frontswap is true, only unuse pages_to_unuse pages; * pages_to_unuse==0 means all pages; ignored if frontswap is false */ -#define SWAP_UNUSE_MAX_TRIES 3 int try_to_unuse(unsigned int type, bool frontswap, unsigned long pages_to_unuse) { @@ -2035,7 +2034,6 @@ int try_to_unuse(unsigned int type, bool frontswap, struct page *page; swp_entry_t entry; unsigned int i; - int retries = 0; if (!si->inuse_pages) return 0; @@ -2117,14 +2115,16 @@ retry: * If yes, we would need to do retry the unuse logic again. * Under global memory pressure, swap entries can be reinserted back * into process space after the mmlist loop above passes over them. - * Its not worth continuosuly retrying to unuse the swap in this case. - * So we try SWAP_UNUSE_MAX_TRIES times. + * + * Limit the number of retries? No: when shmem_unuse()'s igrab() fails, + * a shmem inode using swap is being evicted; and when mmget_not_zero() + * above fails, that mm is likely to be freeing swap from exit_mmap(). + * Both proceed at their own independent pace: we could move them to + * separate lists, and wait for those lists to be emptied; but it's + * easier and more robust (though cpu-intensive) just to keep retrying. */ - if (++retries >= SWAP_UNUSE_MAX_TRIES) - retval = -EBUSY; - else if (si->inuse_pages) + if (si->inuse_pages) goto retry; - out: return (retval == FRONTSWAP_PAGES_UNUSED) ? 0 : retval; } |