On Wed, 2 Nov 2011 11:29:40 -0400 Richard Troth wrote: > So what you're seeing > is random pages which got pushed out at various times during the > stress period. If not needed, they will sit there forever.
Well, maybe not "forever" ... ;-) This lazy (de-)allocation behaviour of Linux is worth remembering. It's just too expensive to continually run the q's to clean this up. Later kernels expose the per-pid (actual) swap usage - I haven't figured out if there is yet a reliable means of discerning disk vs. cache swap usage. > I like to > differentiate between "swap occupancy" and "swap movement". The > occupancy doesn't really hurt you in terms of response time. Most of the time. If memory pressure ramps up *really* quickly, kswapd gets kicked into action to run the q's to free up pages. And it can cycle back through chasing enough memory to free. Not likely in this scenario, but if kswapd needs to work, you wait. Shane ... ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
