From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from penguin.e-mind.com (penguin.e-mind.com [195.223.140.120]) by kvack.org (8.8.7/8.8.7) with ESMTP id UAA31269 for ; Sun, 9 May 1999 20:49:26 -0400 Date: Mon, 10 May 1999 02:57:54 +0200 (CEST) From: Andrea Arcangeli Subject: Re: [PATCH] dirty pages in memory & co. In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: "Eric W. Biederman" Cc: linux-mm@kvack.org List-ID: On 7 May 1999, Eric W. Biederman wrote: >7) Removing the swap lock map, by modify ipc/shm to use the page cache > and vm_stores. I just killed the swap lock map and I just use the swap cache for ipc shm memory. Now I was thinking at the reverse lookup from pagemap to pagetable that you mentioned. It would be easy to that at least for the page/swap cache mappings with the interface I added in my tree. But to support dynamic relocation/defrag of memory on the whole VM we should do that for _all_ pages. And to do the relocation we should run with the GFP pages mapped in a separate pte (not in the 4mbyte page table with the kernel). So I don't know if it would be better to just move all kernel memory (the one available through GFP) to virtual memory and to support the reverse lookup for all pages in the system, or if I should only do the quite-easy backdoor for the page/swap cache. The point is that supporting the reverse lookup for all kernel memory and having all kernel memory in virtual memory, will be a _major_ performance hit for all operations according to me. Right now i would need the reverse lookup only for the mapped cache because I would like to avoid to run swap_out to know if the pte is been accessed or not and in the case it's an old pte I could unmap the mmapped-page directly from shrink_mmap. But I am not convinced this will be an improvement too because I just run swap_out at the right time... Comments? Andrea Arcangeli -- To unsubscribe, send a message with 'unsubscribe linux-mm my@address' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://humbolt.geo.uu.nl/Linux-MM/