From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 6 Mar 1998 04:06:22 -0500 (U) From: "Benjamin C.R. LaHaise" Subject: Re: [PATCH] kswapd fix & logic improvement In-Reply-To: <19980304093300.08111@Elf.mj.gts.cz> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Pavel Machek Cc: Rik van Riel , "Michael L. Galbraith" , linux-mm , linux-kernel List-ID: Hello! On Wed, 4 Mar 1998, Pavel Machek wrote: ... > > Not only that, but the network activity X induces puts additional stress > > on an already low-memory system by allocating lots of unswappable memory. > > When might we see Pavel's patches to the networking stack meant to get > > swapping over TCP working, but I think they'll really help stability on > > systems with low-memory and busy networks, get integrated? > > Sorry? My patches are usable only if you are trying to swap over > network. They will not help on low-memory systems, unless that systems > also lack hard-drives. It is usually much better to swap onto local > drive than over network. If they're setup the way I think they are, you're mistaken. ;-) I'm thinking of the pathelogical case where the system is thrown into a state where atomic memory consumption is occurring faster than the system can free up memory. This could occur on a system with, say 100Mbps ethernet and a low-end IDE drive (~5-7MBps peak) if we're using TCP with large windows and have a *large* number of sockets open and receiving data. Incoming packets could consume up to 10MB of GFP_ATOMIC memory per second - ouch! With your patch, once we hit a danger zone, the system starts dropping network packets, right? That way there will still be enough memory for allocating buffer heads and such to swap out as nescessary... -ben