From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 12 May 2000 21:36:13 +0200 (CEST) From: Ingo Molnar Reply-To: mingo@elte.hu 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: Linus Torvalds Cc: Rik van Riel , Andrea Arcangeli , MM mailing list , linux-kernel@vger.rutgers.edu List-ID: On Fri, 12 May 2000, Linus Torvalds wrote: > > i initially tested pre7-9 and it showed bad behavior: high kswapd activity > > trying to balance highmem, while the pagecache is primarily filled from > > the highmem. I dont think this can be fixed without 'silencing' > > ZONE_HIGHMEM's balancing activities: the pagecache allocates from highmem > > so it puts direct pressure on the highmem zone. > > If this is true, then that is a bug in the allocator. i just re-checked final pre7-2.3.99, and saw similar behavior. Once ZONE_HIGHMEM is empty kswapd eats ~6% CPU time (constantly running), highmem freecount (in /proc/meminfo) fluctuating slightly above zero, but pagecache is not growing anymore - although there is still lots of ZONE_NORMAL RAM around. > anyway. So before you touch the memory allocator logic, you might want to > change the > > if (tsk->need_resched) > schedule(); > > to a > > if (tsk->need_resched) > goto sleep; > > (and add a "sleep:" thing to inside the if-statement that makes us go to > sleep). That way, if we end up scheduling away from kswapd, we won't waste > time scheduling back unless we really should. ok, will try this, and will try to find where it fails. Ingo -- 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/