On 4/14/25 5:08 AM, Peter Zijlstra wrote:
[ math and such ]
The zero_vruntime patch I gave earlier should avoid this particular issue.
Here's a crash with the zero runtime patch. I'm trying to reproduce this outside of prod so we can crank up the iteration speed a bit.
-chris
nr_running = 2 zero_vruntime = 19194347104893960 avg_vruntime = 6044054790 avg_load = 2 curr = { cgroup urgent vruntime = 24498183812106172 weight = 3561684 => 3478 rq = { nr_running = 0 zero_vruntime = 505000008215941 avg_vruntime = 0 avg_load = 0 curr = { cgroup urgent/-610604968056586240 vruntime = 505000008302509 weight = 455902 => 445 rq = { nr_running = 0 zero_vruntime = 12234709899 avg_vruntime = 0 avg_load = 0 curr = { task = 279047 (fc0) vruntime = 12237278090 weight = 15360 => 15 } tasks_timeline = [ ] } } tasks_timeline = [ ] } } tasks_timeline = [ { cgroup optional vruntime = 19194350126921355 weight = 1168 => 2 rq = { nr_running = 2 zero_vruntime = 440280059357029 avg_vruntime = 476 avg_load = 688 tasks_timeline = [ { cgroup optional/-610613050111295488 vruntime = 440280059333960 weight = 291271 => 284 rq = { nr_running = 5 zero_vruntime = 65179829005 avg_vruntime = 0 avg_load = 75 tasks_timeline = [ { task = 261672 (fc0) vruntime = 65189926507 weight = 15360 => 15 }, { task = 261332 (fc0) vruntime = 65189480962 weight = 15360 => 15 }, { task = 261329 (enc1:0:vp9_fbv) vruntime = 65165843516 weight = 15360 => 15 }, { task = 261334 (dec0:0:hevc_fbv) vruntime = 65174065035 weight = 15360 => 15 }, { task = 261868 (fc0) vruntime = 65179829005 weight = 15360 => 15 }, ] } }, { cgroup optional/-610609318858457088 vruntime = 440280059373247 weight = 413911 => 404 rq = { nr_running = 1 zero_vruntime = 22819875784 avg_vruntime = 0 avg_load = 15 tasks_timeline = [ { task = 273291 (fc0) vruntime = 22819875784 weight = 15360 => 15 }, ] } }, ] } }, ]