On Tue, 27 Apr 2010, KAMEZAWA Hiroyuki wrote: > On Mon, 26 Apr 2010 15:33:33 -0700 > Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > On Sun, 25 Apr 2010 09:13:49 +0200 > > Pavel Machek <pavel@xxxxxx> wrote: > > > > > Hi! > > > > > > > I captured this output of vmstat. The machine was freeing cache and > > > > swapping out pages even when there was a plenty of free memory. > > > > > > > > The machine is sparc64 with 1GB RAM with 2.6.34-rc4. This abnormal > > > > swapping happened during running spadfsck --- a fsck program for a custom > > > > filesystem that caches most reads in its internal cache --- so it reads > > > > buffers and allocates memory at the same time. > > > > > > > > Note that sparc64 doesn't have any low/high memory zones, so it couldn't > > > > be explained by filling one zone and needing to allocate pages in it. > > > > > > Fragmented memory + high-order allocation? > > > > Yeah, could be. I wonder which slab/slub/slob implementation you're > > using, and what page sizes it uses for dentries, inodes, etc. Can you > > have a poke in /prob/slabinfo? It uses one page-per-slab for dentries and two for inodes. But there was certainly no dentry or inode-based load --- the machine runs without X with minimum daemons, there is no major background work. There was just a process reading 128-kbyte blocks from a raw device and caching them in its userspace that triggered this. Can it be that kernel uses high-order allocations for reading from a buffer cache? > And please /proc/buddyinfo and /proc/zoneinfo when the system is swappy. It happens rarely, I don't know if I catch it at the right time. The report I sent, was what I found in a scrollback of vmstat. I didn't catch it in real time. > Thanks, > -Kame Mikulas -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>