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 --- 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 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/