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 HAA01823 for ; Mon, 18 Jan 1999 07:17:13 -0500 Date: Mon, 18 Jan 1999 11:00:20 +0100 (CET) From: Andrea Arcangeli Reply-To: Andrea Arcangeli Subject: Re: [patch] NEW: arca-vm-21, swapout via shrink_mmap using PG_dirty 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: Linus Torvalds , linux-kernel@vger.rutgers.edu, linux-mm@kvack.org List-ID: On 18 Jan 1999, Eric W. Biederman wrote: > LT> and (b) as you noticed, it increases fragmentation. > > This is only because he didn't implement any kind of request queue. A > fifo queue of pages to write would have keep performance up at current > levels. Infact I didn't wanted having to alloc more memory in order to free memory (it's something I like to avoid). But the point is that I think that swapping out from shrink_mmap() even if doing ordered I/O is not a win. Try, benchmark and let me know your results, maybe I am wrong. And with a FIFO also shrink_mmap() would change in order to do what swap_out() is doing right now. And btw I think that the fifo could be approssimated to a browse in the swap cache. > LT> The reason PG_dirty should be a win for shared mappings is: (a) it gets > LT> rid of the file write semaphore problem in a very clean way and > > Nope. Because we can still have some try to write to file X. > That write needs memory, and we try to swapout a mapping of file X. > Unless you believe it implies the write outs then must use a seperate process. Agreed. I just pointed this out, but maybe I did not understood _where_ we should do the write to disk to reclaim memory. Andrea Arcangeli -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org