From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 29 Aug 2004 15:17:57 -0700 From: William Lee Irwin III Subject: Re: Kernel 2.6.8.1: swap storm of death - nr_requests > 1024 on swap partition Message-ID: <20040829221757.GA5492@holomorphy.com> References: <20040828144303.0ae2bebe.akpm@osdl.org> <20040828215411.GY5492@holomorphy.com> <20040828151349.00f742f4.akpm@osdl.org> <20040828222816.GZ5492@holomorphy.com> <20040829033031.01c5f78c.akpm@osdl.org> <20040829141526.GC10955@suse.de> <20040829141718.GD10955@suse.de> <20040829131824.1b39f2e8.akpm@osdl.org> <20040829203011.GA11878@suse.de> <20040829135917.3e8ffed8.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040829135917.3e8ffed8.akpm@osdl.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Jens Axboe , karl.vogel@pandora.be, linux-mm@kvack.org List-ID: 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