Mikael Pettersson writes:
Mikael Pettersson writes: > Geert Uytterhoeven writes: > > Hi Mikael, > > > > On Fri, Jun 6, 2014 at 1:38 PM, Mikael Pettersson <mikpelinux@xxxxxxxxx> wrote: > > > Since updating my ARAnym VMs from 3.12.16 to 3.13.11 I see kswapd0 > > > and ksoftirqd/0 consume inordinate amounts of CPU. kswapd0 often > > > rises to about 30-50% CPU even though RAM shouldn't be anywhere near > > > depleted (768GB, a gcc bootstrap running in a screen session). > > > kswapd0 tends to stay this way until I drop caches, but doing that > > > doesn't always fix it. I also sometimes see ksoftirqd/0 consume > > > 5-30% CPU. > > > > > > Reverting to 3.12.16 completely eliminates these problems. > > > > Any chance to bisect it? > > > > > I haven't tested 3.14 or 3.15-rc yet. > > > > Would be good to know, though, as it may have been fixed. > > However, as v3.13.11 is the most recent stable version of v3.13, this may be > > an elsewhere unknown and thus unfixed issue. > > I've just started a gcc-4.8 bootstrap on 3.14.5, and then I'll try 3.15 > if it isn't fixed in 3.14. 3.14.5 is also affected by the bug. Dropping caches fixed kswapd0, but instead ksoftirqd/0 jumped to 20-40%, and it refuses to calm down.
3.15-rc8 is also affected. It took a while before triggering, but I just got a kswapd0 CPU hog there too. Dropping page cache helped this time. Another observation is that ksoftirqd/0 seem to consistently consume much more CPU in 3.14/3.15 than in 3.12. Usually not hugely so at specific time points, but the accumulated CPU for it on a system that's been up a couple of days with constant load is looking a bit scary. -- To unsubscribe from this list: send the line "unsubscribe linux-m68k" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
