diff options
author | Christoph Lameter <clameter@engr.sgi.com> | 2006-01-08 09:00:55 (GMT) |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-09 04:12:42 (GMT) |
commit | d0d963281ccb22e6f339bfdd75c6b2e31351929f (patch) | |
tree | ddeb3d1cf73675d71b21be8893b16cf5014c1bc5 /mm/vmscan.c | |
parent | d498471133ff1f9586a06820beaeebc575fe2814 (diff) | |
download | linux-fsl-qoriq-d0d963281ccb22e6f339bfdd75c6b2e31351929f.tar.xz |
[PATCH] SwapMig: Switch error handling in migrate_pages to use -Exx
Use -Exxx instead of numeric return codes and cleanup the code in
migrate_pages() using -Exx error codes.
Consolidate successful migration handling
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/vmscan.c')
-rw-r--r-- | mm/vmscan.c | 56 |
1 files changed, 34 insertions, 22 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 5eecb51..bf903b2 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -606,10 +606,6 @@ int putback_lru_pages(struct list_head *l) /* * swapout a single page * page is locked upon entry, unlocked on exit - * - * return codes: - * 0 = complete - * 1 = retry */ static int swap_page(struct page *page) { @@ -650,7 +646,7 @@ unlock_retry: unlock_page(page); retry: - return 1; + return -EAGAIN; } /* * migrate_pages @@ -669,6 +665,8 @@ retry: * is only swapping out pages and never touches the second * list. The direct migration patchset * extends this function to avoid the use of swap. + * + * Return: Number of pages not migrated when "to" ran empty. */ int migrate_pages(struct list_head *from, struct list_head *to, struct list_head *moved, struct list_head *failed) @@ -679,6 +677,7 @@ int migrate_pages(struct list_head *from, struct list_head *to, struct page *page; struct page *page2; int swapwrite = current->flags & PF_SWAPWRITE; + int rc; if (!swapwrite) current->flags |= PF_SWAPWRITE; @@ -689,22 +688,23 @@ redo: list_for_each_entry_safe(page, page2, from, lru) { cond_resched(); - if (page_count(page) == 1) { + rc = 0; + if (page_count(page) == 1) /* page was freed from under us. So we are done. */ - list_move(&page->lru, moved); - continue; - } + goto next; + /* * Skip locked pages during the first two passes to give the * functions holding the lock time to release the page. Later we * use lock_page() to have a higher chance of acquiring the * lock. */ + rc = -EAGAIN; if (pass > 2) lock_page(page); else if (TestSetPageLocked(page)) - goto retry_later; + goto next; /* * Only wait on writeback if we have already done a pass where @@ -713,18 +713,19 @@ redo: if (pass > 0) { wait_on_page_writeback(page); } else { - if (PageWriteback(page)) { - unlock_page(page); - goto retry_later; - } + if (PageWriteback(page)) + goto unlock_page; } + /* + * Anonymous pages must have swap cache references otherwise + * the information contained in the page maps cannot be + * preserved. + */ if (PageAnon(page) && !PageSwapCache(page)) { if (!add_to_swap(page, GFP_KERNEL)) { - unlock_page(page); - list_move(&page->lru, failed); - nr_failed++; - continue; + rc = -ENOMEM; + goto unlock_page; } } @@ -732,12 +733,23 @@ redo: * Page is properly locked and writeback is complete. * Try to migrate the page. */ - if (!swap_page(page)) { + rc = swap_page(page); + goto next; + +unlock_page: + unlock_page(page); + +next: + if (rc == -EAGAIN) { + retry++; + } else if (rc) { + /* Permanent failure */ + list_move(&page->lru, failed); + nr_failed++; + } else { + /* Success */ list_move(&page->lru, moved); - continue; } -retry_later: - retry++; } if (retry && pass++ < 10) goto redo; |