From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 4 Nov 1999 18:58:06 +0100 (CET) From: Ingo Molnar Subject: Re: [Patch] shm cleanups In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Rohland Cc: MM mailing list , woodman@missioncriticallinux.com, Linus Torvalds List-ID: On 4 Nov 1999, Christoph Rohland wrote: > I do get swapping also with 8GB of RAM, but it runs out of memory > before running out of swap space since prepare_highmem_swapout is > failing way to often. > > (It then locks up since it cannot free the shm segments and so is > unable to free the memory. This should be perhaps addressed later in > the oom handler. It cannot handle the case where nearly all memory is > allocted in shm segments) ho humm. I think prepare_highmem_swapout() has a design bug. It's way too naive in low memory situations, it should keep a short list of pages for emergency swapout. It's the GFP_ATOMIC that is failing too often, right? i believe we should have some explicit mechanizm that tells vmscan that there is 'IO in progress which will result in more memory', to distinct between true out-of-memory and 'wait a little bit to get more RAM' cases? I think we'd have a lot less to worry about and there would be a much clearer distinction between true out-of-mem and 'just cannot allocate it right now but help is on the way' cases. Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://humbolt.geo.uu.nl/Linux-MM/