From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: the new VMt Date: Mon, 25 Sep 2000 16:16:56 +0100 (BST) In-Reply-To: from "Ingo Molnar" at Sep 25, 2000 05:16:06 PM MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: From: Alan Cox Sender: owner-linux-mm@kvack.org Return-Path: To: mingo@elte.hu Cc: Alan Cox , Andrea Arcangeli , Marcelo Tosatti , Linus Torvalds , Rik van Riel , Roger Larsson , MM mailing list , linux-kernel@vger.kernel.org List-ID: > > GFP_KERNEL has to be able to fail for 2.4. Otherwise you can get > > everything jammed in kernel space waiting on GFP_KERNEL and if the > > swapper cannot make space you die. > > if one can get everything jammed waiting for GFP_KERNEL, and not being > able to deallocate anything, thats a VM or resource-limit bug. This > situation is just 1% RAM away from the 'root cannot log in', situation. Unless Im missing something here think about this case 2 active processes, no swap #1 #2 kmalloc 32K kmalloc 16K OK OK kmalloc 16K kmalloc 32K block block so GFP_KERNEL has to be able to fail - it can wait for I/O in some cases with care, but when we have no pages left something has to give -- 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.eu.org/Linux-MM/