From linux-mm Sun Aug 29 22:17:57 2004 From: William Lee Irwin III Date: Sun, 29 Aug 2004 22:17:57 +0000 To: linux-mm Subject: Re: Kernel 2.6.8.1: swap storm of death - nr_requests > 1024 on swap partition Message-Id: <20040829221757.GA5492 () holomorphy ! com> X-MARC-Message: https://marc.info/?l=linux-mm&m=109381798027442 Jens Axboe wrote: >> Why you do see a difference is that when ->max_queued isn't valid, you >> end up block a lot more in get_request_wait() because cfq_may_queue will >> disallow you to queue a lot more than with the patch. Since other io >> schedulers don't have these sort of checks, they behave like CFQ does >> with the bug in blk_init_queue() fixed. On Sun, Aug 29, 2004 at 01:59:17PM -0700, Andrew Morton wrote: > The changlog wasn't that detailed ;) > But yes, it's the large nr_requests which is tripping up swapout. I'm > assuming that when a process exits with its anonymous memory still under > swap I/O we're forgetting to actually free the pages when the I/O > completes. So we end up with a ton of zero-ref swapcache pages on the LRU. > I assume. Something odd's happening, that's for sure. Maybe we need to be checking for this in end_swap_bio_write() or rotate_reclaimable_page()? -- wli -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org