A shmem cleanup/bugfix patch from Hugh Dickins.
- Minor: in try_to_unuse(), only wait on writeout if we actually
started new writeout. Otherwise, there is no need because a
wait_on_page_writeback() has already been executed against this page.
And it's locked, so no new writeback can start.
- Minor: in shmem_unuse_inode(): remove all the
wait_on_page_writeback() logic. We already did that in
try_to_unuse(), adn the page is locked so no new writeback can start.
- Less minor: add a missing a page_cache_release() to
shmem_get_page_locked() in the uncommon case where the page was found
to be under writeout.
shmem.c | 12 +++---------
swapfile.c | 5 ++---
2 files changed, 5 insertions(+), 12 deletions(-)
--- 2.5.24/mm/shmem.c~shmem-fixes Thu Jul 4 16:17:16 2002
+++ 2.5.24-akpm/mm/shmem.c Thu Jul 4 16:17:16 2002
@@ -426,22 +426,15 @@ found:
swap_free(entry);
ptr[offset] = (swp_entry_t) {0};
- while (inode && (PageWriteback(page) ||
- move_from_swap_cache(page, idx, inode->i_mapping))) {
+ while (inode && move_from_swap_cache(page, idx, inode->i_mapping)) {
/*
* Yield for kswapd, and try again - but we're still
* holding the page lock - ugh! fix this up later on.
* Beware of inode being unlinked or truncated: just
* leave try_to_unuse to delete_from_swap_cache if so.
- *
- * AKPM: We now wait on writeback too. Note that it's
- * the page lock which prevents new writeback from starting.
*/
spin_unlock(&info->lock);
- if (PageWriteback(page))
- wait_on_page_writeback(page);
- else
- yield();
+ yield();
spin_lock(&info->lock);
ptr = shmem_swp_entry(info, idx, 0);
if (IS_ERR(ptr))
@@ -607,6 +600,7 @@ repeat:
spin_unlock(&info->lock);
wait_on_page_writeback(page);
unlock_page(page);
+ page_cache_release(page);
goto repeat;
}
error = move_from_swap_cache(page, idx, mapping);
--- 2.5.24/mm/swapfile.c~shmem-fixes Thu Jul 4 16:17:16 2002
+++ 2.5.24-akpm/mm/swapfile.c Thu Jul 4 16:17:16 2002
@@ -687,11 +687,10 @@ static int try_to_unuse(unsigned int typ
if ((*swap_map > 1) && PageDirty(page) && PageSwapCache(page)) {
swap_writepage(page);
lock_page(page);
- }
- if (PageSwapCache(page)) {
wait_on_page_writeback(page);
- delete_from_swap_cache(page);
}
+ if (PageSwapCache(page))
+ delete_from_swap_cache(page);
/*
* So we could skip searching mms once swap count went
-
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sun Jul 07 2002 - 22:00:13 EST