http://picasaweb.google.com/aidar.eiei/LinuxIo#5533068249408411698 I will look into latencytop output and will figure out a usage pattern that is most annoying with regards to IO. Will try to see what leads to that & if possible to make a screenshot of what is going on. The thing is, I don't think the program that captures the screenshots does it in a meaningful way, because at the moment the system is brought to its knees, I don't think that this particular program (KSnapshot) can get away from being affected. I mean it might take a snapshot which is not representative enough. thanks, Aidar On Thu, Oct 28, 2010 at 5:48 PM, Pekka Enberg <penberg@xxxxxxxxxx> wrote: > On Thu, Oct 28, 2010 at 2:33 PM, Aidar Kultayev <the.aidar@xxxxxxxxx> wrote: >> if it wasn't picasa, it would have been something else. I mean if I >> kill picasa ( later on it was done indexing new pics anyway ), it >> would have been for virtualbox to thrash the io. So, nope, getting rid >> of picasa doesn't help either. In general the systems responsiveness >> or sluggishness is dominated by those io operations going on - the DD >> & CP & probably VBOX issuing whole bunch of its load for IO. > > Do you still see high latencies in vfs_lseek() and vfs_fsync()? I'm > not a VFS expert but looking at your latencytop output, it seems that > fsync grabs ->i_mutex which blocks vfs_llseek(), for example. I'm not > sure why that causes high latencies though it's a mutex we're holding. > > On Thu, Oct 28, 2010 at 2:33 PM, Aidar Kultayev <the.aidar@xxxxxxxxx> wrote: >> Another way I see these delays, is when I leave system overnight, with >> ktorrent & juk(stopped) in the background. It takes some time for >> WM(kwin) to work out ALT+TAB the very next morning. But this might be >> because the WM(kwin & its code) has been swapped out, because of long >> period of not using it. > > Yeah, that's probably paging overhead. > > P.S. Can you please upload latencytop output somewhere and post an URL > to it so other people can also see it? > -- 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>