From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from max.phys.uu.nl (max.phys.uu.nl [131.211.32.73]) by kvack.org (8.8.7/8.8.7) with ESMTP id RAA08101 for ; Thu, 23 Jul 1998 17:33:49 -0400 Date: Thu, 23 Jul 1998 22:28:39 +0200 (CEST) From: Rik van Riel Reply-To: Rik van Riel Subject: Re: Good and bad news on 2.1.110, and a fix In-Reply-To: <35B75FE8.63173E88@star.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Bill Hawes Cc: "Stephen C. Tweedie" , Linus Torvalds , Alan Cox , "David S. Miller" , Ingo Molnar , Mark Hemment , linux-mm@kvack.org, linux-kernel@vger.rutgers.edu List-ID: On Thu, 23 Jul 1998, Bill Hawes wrote: > Stephen C. Tweedie wrote: > > > The patch to page_alloc.c is a minimal fix for the fragmentation > > problem. It simply records allocation failures for high-order pages, > > and forces free_memory_available to return false until a page of at > > least that order becomes available. The impact should be low, since This sound suspiciously like the first version of free_memory_available() that Linus introduced in 2.1.89... > One possible downside is that kswapd infinite looping may become more > likely, as we still have no way to determine when the memory It will happen for sure; just think of what will happen when that 64 kB DMA allocation fails on your 6 MB box :( We saw the results in 2.1.89 and I don't see any reason to repeat the experiments now, at least not until Bill's patch for freeing inodes is merged... > configuration makes it impossible to achieve the memory goal. I still > see this "swap deadlock" in 110 (and all recent kernels) under low > memory or by doing a swapoff. Any ideas on how to best determine an > infeasible memory configuration? Well, freepages.high should be a nice hint as to when to stop; unfortunately it is used now instead of fragmentation issues. Maybe we want to count the number of order-3 memory structures free and keep that number above a certain level (back to Zlatko's 2.1.59 patch :-). Rik. +-------------------------------------------------------------------+ | Linux memory management tour guide. H.H.vanRiel@phys.uu.nl | | Scouting Vries cubscout leader. http://www.phys.uu.nl/~riel/ | +-------------------------------------------------------------------+ -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org