This relays all ASYNC file writeback IOs to the flusher threads. The lesser SYNC pageout()s will work as before (as a last resort). It's a minimal prototype implementation and barely runs without panic. It potentially requires lots of more work to go stable. Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx> --- mm/vmscan.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- linux-next.orig/mm/vmscan.c 2010-07-29 17:07:07.000000000 +0800 +++ linux-next/mm/vmscan.c 2010-07-29 17:09:16.000000000 +0800 @@ -379,6 +379,13 @@ static pageout_t pageout(struct page *pa } if (mapping->a_ops->writepage == NULL) return PAGE_ACTIVATE; + + if (sync_writeback == PAGEOUT_IO_ASYNC && + page_is_file_cache(page)) { + bdi_start_inode_writeback(mapping->host, page->index); + return PAGE_KEEP; + } + if (!may_write_to_queue(mapping->backing_dev_info)) return PAGE_KEEP; @@ -1366,7 +1373,6 @@ shrink_inactive_list(unsigned long nr_to list_add(&page->lru, &putback_list); } - wakeup_flusher_threads(laptop_mode ? 0 : nr_dirty); congestion_wait(BLK_RW_ASYNC, HZ/10); /* -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>