On Mon, Jan 27, 2020 at 05:31:09PM -0500, Steven Rostedt wrote:
On Mon, 27 Jan 2020 14:36:24 -0500 Steven Rostedt rostedt@goodmis.org wrote:
On Mon, 27 Jan 2020 13:19:28 -0600 Tom Zanussi zanussi@kernel.org wrote:
It does fix the issue for me and passes the selftests. Remember that 4.19 doesn't have the .trace() hist action - you need to use the event name e.g. .first()
Yeah I did that, but it was still clearing out the start variable when I tried. I'll test the full commits next, right after I fix my git repo that got corrupted because it had an alternative based on a repo that rebased :-(
Finally got my repo fixed. Yes, after applying the two commits, this failed patch applies fine, and it does fix the issue. The test I did:
# mount -t tracefs nodev /sys/kernel/tracing # cd /sys/kernel/tracing # echo 'first u64 start_time u64 end_time pid_t pid u64 delta' >> synthetic_events # echo 'hist:keys=pid:start=common_timestamp' > events/sched/sched_waking/trigger # echo 'hist:keys=next_pid:delta=common_timestamp-$start,start2=$start:onmatch(sched.sched_waking).first($start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger # cat events/sched/sched_switch/hist
And make sure there were events:
# cat events/sched/sched_switch/hist # event histogram # # trigger info: hist:keys=next_pid:vals=hitcount:delta=common_timestamp-$start,start2=$start:sort=hitcount:size=2048:clock=global:onmatch(sched.sched_waking).first($start2,common_timestamp,next_pid,$delta) [active] #
{ next_pid: 1246 } hitcount: 1 { next_pid: 153 } hitcount: 1 { next_pid: 21 } hitcount: 1 { next_pid: 26 } hitcount: 1 { next_pid: 1245 } hitcount: 1 { next_pid: 1613 } hitcount: 1 { next_pid: 1303 } hitcount: 1 { next_pid: 1375 } hitcount: 1 { next_pid: 67 } hitcount: 1 { next_pid: 41 } hitcount: 1 { next_pid: 12 } hitcount: 1 { next_pid: 31 } hitcount: 1 { next_pid: 46 } hitcount: 1 { next_pid: 36 } hitcount: 1 { next_pid: 16 } hitcount: 1 { next_pid: 606 } hitcount: 3 { next_pid: 102 } hitcount: 3 { next_pid: 936 } hitcount: 3 { next_pid: 13 } hitcount: 6 { next_pid: 10 } hitcount: 7 { next_pid: 1584 } hitcount: 13 { next_pid: 1579 } hitcount: 27 { next_pid: 145 } hitcount: 30 { next_pid: 1417 } hitcount: 33
Totals: Hits: 140 Entries: 24 Dropped: 0
Greg,
This patch is dependent on commits 656fe2ba85e81d00e4447bf77b8da2be3c47acb2 and de40f033d4e84e843d6a12266e3869015ea9097c
Can you backport them as well to 4.19 and then apply this fix?
Will do, thanks!
greg k-h