btrfs: factor our read/write stage off csum_tree_block into its callers

[linux-2.6-block.git] / mm / swapfile.c

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 71383625a582c47dd87281655329b6eeada87121..cf63b5f01adf7da9d1def93f8763b50243adc698 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2116,12 +2116,11 @@ retry:
         * Under global memory pressure, swap entries can be reinserted back
         * into process space after the mmlist loop above passes over them.
         *
-        * 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.
+        * Limit the number of retries? No: when mmget_not_zero() above fails,
+        * that mm is likely to be freeing swap from exit_mmap(), which proceeds
+        * at its own independent pace; and even shmem_writepage() could have
+        * been preempted after get_swap_page(), temporarily hiding that swap.
+        * It's easy and robust (though cpu-intensive) just to keep retrying.
         */
        if (si->inuse_pages) {
                if (!signal_pending(current))