On Thu, Mar 14, 2024 at 10:21:21PM +0100, 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. > I notice CPU3 didn't have its own non-deferrable timer queued (local or global), so could the following happen? timer_base_try_to_set_idle(): __get_next_timer_interrupt(): fetch_next_timer_interrupt(): // nextevt_local == nextevt_global == basej + NEXT_TIMER_MAX_DELTA // tevt->local == tevt->gloabl = KTIME_MAX timer_use_tmigr(): tmigr_cpu_deactivate(): __tmigr_cpu_deactivate(): // tmc->cpuevt.ignore untouched still == true walk_groups(&tmigr_inactive_up, ...): tmigr_inactive_up(): data->remote = true; tmigr_update_events(): if (child) { // child is NULL ... } else { first_childevt = evt = data->evt; if (evt->ignore && !remote) return true; // no remote tick is picked. ... } Regards, Boqun > 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.
