From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 18 May 2000 18:58:00 -0700 (PDT) From: Andrea Arcangeli Subject: Re: [patch] balanced highmem subsystem under pre7-9 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: Ingo Molnar Cc: Rik van Riel , Linus Torvalds , MM mailing list , linux-kernel@vger.rutgers.edu List-ID: [ sorry for the late reply ] On Fri, 12 May 2000, Ingo Molnar wrote: >On Fri, 12 May 2000, Rik van Riel wrote: > >> But we *can* split the HIGHMEM zone into a bunch of smaller >> ones without affecting performance. Just set zone->pages_min >> and zone->pages_low to 0 and zone->pages_high to some smallish >> value. Then we can teach the allocator to skip the zone if: >> 1) no obscenely large amount of free pages >> 2) zone is locked by somebody else (TryLock(zone->lock)) > >whats the point of this splitup? (i suspect there is a point, i just >cannot see it now. thanks.) I quote email from Rik of 25 Apr 2000 23:10:56 on linux-mm: -- Message-ID: -- We can do this just fine. Splitting a box into a dozen more zones than what we have currently should work just fine, except for (as you say) higher cpu use by kwapd. If I get my balancing patch right, most of that disadvantage should be gone as well. Maybe we *do* want to do this on bigger SMP boxes so each processor can start out with a separate zone and check the other zone later to avoid lock contention? -------------------------------------------------------------- I still strongly think that the current zone strict mem balancing design is very broken (and I also think to be right since I believe to see the whole picture) but I don't think I can explain my arguments better and/or more extensively of how I just did in linux-mm some week ago. If you see anything wrong in my reasoning please let me know. The interesting thread was "Re: 2.3.x mem balancing" (the start were off list) in linux-mm. Andrea -- 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/