On 8/27/07, Mike Fleetwood <mike.fleetwood@xxxxxxxxxxxxxx> wrote: > Hi, > > Since I upgraded my FC6 box from kernel-2.6.20-1.2962.fc6 to > kernel-2.6.22.1-32.fc6, and now 2.6.22.2-42.fc6, I am getting pauses > from the whole OS. They last ~1 second and occur every few minutes. > Every application becomes unresponsive for the duration. The 1 second > scheduler latency this causes is long enough for my music player to be > effected and the audio track to be interrupted. This makes the fault > very easy to hear. At the same time kernel thread events/0 seems to > use all the CPU time. Here is the first few lines of top's output > when a pause happens: > top - 21:39:41 up 1:17, 2 users, load average: 1.05, 1.20, 1.24 > Tasks: 138 total, 4 running, 134 sleeping, 0 stopped, 0 zombie > Cpu(s): 2.3%us, 29.3%sy, 68.4%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st > Mem: 2074880k total, 1355244k used, 719636k free, 62144k buffers > Swap: 1004052k total, 0k used, 1004052k free, 882684k cached > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 5525 mike 39 19 202m 81m 4016 R 68.4 4.0 13:07.46 hadcm3transum_5 > 6 root 15 -5 0 0 0 S 28.5 0.0 0:53.40 events/0 > 3619 mike 20 0 45620 8264 5856 S 0.9 0.4 0:18.58 xmms > 3318 root 20 0 328m 46m 8132 S 0.6 2.3 1:39.60 Xorg > 3524 mike 20 0 76728 23m 9640 S 0.6 1.2 1:13.15 bittorrent > 3557 mike 20 0 211m 115m 30m S 0.6 5.7 3:54.24 firefox-bin > 3489 mike 20 0 57240 23m 15m S 0.3 1.1 0:04.02 gnome-terminal > 5583 root 20 0 2204 1100 832 R 0.3 0.1 0:01.14 top > 28.5% CPU time used by events/0 of a single 3 second top refresh is > 0.85 seconds of CPU time. Rebooting back to kernel 2.6.20 completely > fixes it. > > Has any one else seen this issue? > Does anyone know what kernel thread events/0 does? It's a per processor work queue. This is a data structure used to handle deferred work. As you have only one processor, you get an events/0 (events/1, etc.. in SMP). I've never seen that thread taking so much cpu time... maybe a kernel developer can throw some light here > Could this be related to CFS newly introduced into Fedora's kernel 2.6.22? > Can anybody suggest how to fix this issue? > > Thanks, > Mike > > -- > fedora-list mailing list > fedora-list@xxxxxxxxxx > To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list >
