The Linux 6.19 kernel has been a bit bumpy in the scheduler department but at least one fix is on the way for addressing fallout.

[1]Linux 6.19 does bring some nice performance improvements overall but during my early testing there were [2]some regressions and I ended up [3]bisecting some of them to the scheduler changes in Linux 6.19 .

Intel's Kernel Test Robot did also [4]report a scheduler regression with Schbench using a Phoronix benchmark run:

"kernel test robot noticed a 52.4% regression of pts.schbench.32.usec,_99.9th_latency_percentile"

That regression was spotted on [5]this scheduler commit .

Queued a few days ago into the tip/tip.git's sched/core branch is [6]sched/fair: Fix sched_avg fold to fix that reported 52.4% regression:

"After the robot reported a regression wrt commit: 089d84203ad4 ("sched/fair: Fold the sched_avg update"), Shrikanth noted that two spots missed a factor se_weight()."

That patch will presumably be sent in soon for the ongoing Linux 6.19 cycle.



[1] https://www.phoronix.com/review/amd-epyc-9965-linux-619

[2] https://www.phoronix.com/news/Linux-6.19-Early-Benchmarks

[3] https://www.phoronix.com/review/linux-619-sched-regress

[4] https://lore.kernel.org/oe-lkp/202512181208.753b9f6e-lkp@intel.com/

[5] https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=089d84203ad42bc8fd6dbf41683e162ac6e848cd

[6] https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=sched/core&id=6ab7973f254071faf20fe5fcc502a3fe9ca14a47