On Thu, Mar 14 2024 at 22:21, Thomas Gleixner wrote: > On Thu, Mar 14 2024 at 21:45, Thomas Gleixner wrote: >> On Thu, Mar 14 2024 at 12:09, Florian Fainelli wrote: >>> https://gist.github.com/ffainelli/cb562c1a60ef8e0e69e7d42143c48e8f >>> >>> this one is does include the tmigr events. Thanks! >> >> You need 8ca1836769d758e4fbf5851bb81e181c52193f5d too. > > So from the above trace it's clear where it goes south: > > [ 236.318158] <idle>-0 3..s.. 2928466us : tmigr_handle_remote: group=aecb05cb lvl=0 > [ 236.326526] <idle>-0 3d.s.. 2928467us : tmigr_handle_remote_cpu: cpu=0 parent=aecb05cb wakeup=9223372036854775807 > [ 236.357809] <idle>-0 3d.s.. 2928469us : tmigr_update_events: child=00000000 group=aecb05cb group_lvl=0 child_active=0 group_active=8 nextevt=3103000000 next_expiry=2934000000 child_evt_expiry=0 child_evtcpu=0 > > [ 236.377222] <idle>-0 0dn... 2928471us : tmigr_cpu_active: cpu=0 parent=aecb05cb wakeup=9223372036854775807 > [ 236.387765] <idle>-0 0dn... 2928471us : tmigr_group_set_cpu_active: group=aecb05cb lvl=0 numa=0 active=9 migrator=8 parent=00000000 childmask=1 > > [ 236.401526] <idle>-0 0d.... 2928477us : tmigr_update_events: child=00000000 group=aecb05cb group_lvl=0 child_active=0 group_active=8 nextevt=3103000000 next_expiry=2934000000 child_evt_expiry=0 child_evtcpu=0 > [ 236.420940] <idle>-0 0d.... 2928478us : tmigr_group_set_cpu_inactive: group=aecb05cb lvl=0 numa=0 active=8 migrator=8 parent=00000000 childmask=1 > [ 236.434874] <idle>-0 0d.... 2928478us : tmigr_cpu_idle: cpu=0 parent=aecb05cb nextevt=3103000000 wakeup=9223372036854775807 > > [ 236.446896] <idle>-0 3d.... 2929469us : tmigr_group_set_cpu_inactive: group=aecb05cb lvl=0 numa=0 active=0 migrator=ff parent=00000000 childmask=8 > [ 236.460916] <idle>-0 3d.... 2929470us : tmigr_cpu_idle: cpu=3 parent=aecb05cb nextevt=9223372036854775807 wakeup=9223372036854775807 > [ 236.473721] <idle>-0 3d.... 2934471us : tmigr_cpu_new_timer_idle: cpu=3 parent=aecb05cb nextevt=9223372036854775807 wakeup=9223372036854775807 > > CPU3 is the last active CPU and goes idle. So it should take care of the > pending events, but it does not. > > This is the next trace entry where CPU0 magically comes back to life. > > [ 236.487393] <idle>-0 0d.s.. 162001359us : timer_cancel: timer=8c725d84 > > 8ca1836769d758e4fbf5851bb81e181c52193f5d is related, but dos not fully > explain the fail. I haven't yet spotted where this goes into lala land. The first expiring pending global timer is this one: [ 236.112089] kworker/-1198 1d.... 2923481us : timer_start: timer=ffd09a61 function=process_timeout expires=4294670230 [timeout=10] bucket_expiry=4294670231 cpu=1 idx=23 flags= Bucket expiry is the relevant number: 4294670231 (jiffies) The last timer expiry happened about 1ms before the fail: [ 236.344917] <idle>-0 3..s.. 2928468us : timer_expire_entry: timer=2f09af03 function=process_timeout now=4294670225 baseclk=4294670225 Jiffies at that point: 4294670225 AFAICT this is a HZ=1000 configuration. 4294670231 - 4294670225 = 6 So the relevant wakeup should be around 2934468us which is damned close to the point where the last active CPU vanishes into idle: > [ 236.446896] <idle>-0 3d.... 2929469us : tmigr_group_set_cpu_inactive: group=aecb05cb lvl=0 numa=0 active=0 migrator=ff parent=00000000 childmask=8 > [ 236.460916] <idle>-0 3d.... 2929470us : tmigr_cpu_idle: cpu=3 parent=aecb05cb nextevt=9223372036854775807 wakeup=9223372036854775807 > [ 236.473721] <idle>-0 3d.... 2934471us : tmigr_cpu_new_timer_idle: cpu=3 parent=aecb05cb nextevt=9223372036854775807 wakeup=9223372036854775807 Unless someone beats me to it, I'm going to continue staring at that code tomorrow as my brain has started to melt by now. Thanks, tglx
