On Thu, 2007-08-09 at 12:11 +0200, Pavel Machek wrote: > Hi! > > > I've been working on this for quite some time. And should post again > > soon. Please see the patches: > > > > http://programming.kicks-ass.net/kernel-patches/vm_deadlock/current/ > > > > For now it requires one uses SLUB, I hope that SLAB will go away (will > > save me the trouble of adding support) and I guess I ought to do SLOB > > some time (if that does stay). > > > > You'd need the first 22 patches of that series, and then call > > sk_set_memalloc(sk) on the proper socket, and do some fiddling with the > > reconnect logic. See nfs-swapfile.patch for examples. > > What do you use for testing? I set up ata over ethernet... swapping > over that should deadlock w/o your patches. > > But I'm able to compile kernel (-j 10) on 128MB machine, and I tried > cat /dev/zero | grep foo to exhaust memory... and could not reproduce > the deadlock. Should I pingflood? Tweak down ammount of atomic memory > avaialable to make deadlocks easier to reproduce?
I usually test swap over NFS in the following manner, I setup a regular inet service on the machine (apache or a bunch of ncat sockets piping to files or something) and run a heavy workload on the machine (128M): 2*64M file backed thrashers and 2*64M anonymous thrashers. Then I start clients for the regular inet service, wait for a bit, and shut down the NFS server. This makes the machine grind to a halt, I then restart the NFS server, wait for it to reconnect and the client to come alive again. Without the last few swap-over-NFS patches this last bit - getting back out of that situation - never happens. The basic idea is to make connectivity to the machine where swap traffic goes very hard (pull a cable, cleanly shut down the server) and to keep other network traffic pounding the machine. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
