From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 5 Nov 2007 15:17:23 -0500 From: Rik van Riel Subject: Re: [RFC Patch] Thrashing notification Message-ID: <20071105151723.71b3faaf@bree.surriel.com> In-Reply-To: <20071105183025.GA4984@dmt> References: <20071105183025.GA4984@dmt> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Marcelo Tosatti Cc: Daniel =?UTF-8?B?U3DDpW5n?= , linux-mm@kvack.org, drepper@redhat.com, akpm@linux-foundation.org, mbligh@mbligh.org, balbir@linux.vnet.ibm.com, 7eggert@gmx.de List-ID: On Mon, 5 Nov 2007 13:30:25 -0500 Marcelo Tosatti wrote: > Hooking into try_to_free_pages() makes the scheme suspectible to > specifics such as: The specific of where the hook is can be changed. I am sure the two of you can come up with the best way to do things. Just keep shooting holes in each other's ideas until one idea remains which neither of you can find a problem with[1] :) > Remember that notifications are sent to applications which can allocate > globally... This is the bigger problem with the sysfs code: every task that watches the sysfs node will get woken up. That could be a big problem when there are hundreds of processes watching that file. Marcelo's code, which only wakes up one task at a time, has the potential to work much better. That code can also be enhanced to wake up tasks that use a lot of memory on the specific NUMA node that has a memory shortage. [1] Yes, that is how I usually come up with VM ideas :) -- "Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." - Brian W. Kernighan -- 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: email@kvack.org