From aa10065557f982929772be1606f80d6f30bfde2f Mon Sep 17 00:00:00 2001 From: Tyler Nijmeh Date: Mon, 21 Sep 2020 08:28:20 -0700 Subject: [PATCH] Fix panic with HRTICK Signed-off-by: Tyler Nijmeh --- README.md | 3 --- ktweak | 1 - 2 files changed, 4 deletions(-) diff --git a/README.md b/README.md index 3833647..7e3493f 100644 --- a/README.md +++ b/README.md @@ -116,9 +116,6 @@ By scheduling the last woken task first, we can increase cache locality since th ### TTWU Queue Allow the scheduler to place tasks on their origin CPU, increasing cache locality if the CPU is non-local (i.e. a cache hit would definitely have been missed). -### HRTick -Usually, the scheduler is interrupted once every 1/HZ milliseconds if no task directly interrupts it. This arises an issue where we rely on opportunism to keep scheduling latencies low. Enabling HRTick will schedule an hrtimer that is capable of interrupting the kernel more often than 1/HZ milliseconds, based on the current number of running tasks. In testing using schbench, latencies (and max latencies) were reduced to almost half of their original values. - ### Governor Tweaks * {up_,down_}rate_limit_us / min_sample_time: 0 --> 5000: Only adjust frequencies once per scheduling cycle to reduce jitter or stutter caused by unrealistic frequency scaling. * hispeed_load / go_hispeed_load: 90: Jump to a higher frequency if we are approaching the end of the frequency list, where a task may begin to starve or begin to stutter. diff --git a/ktweak b/ktweak index cb04362..102ffd9 100644 --- a/ktweak +++ b/ktweak @@ -122,7 +122,6 @@ if [[ -f "/sys/kernel/debug/sched_features" ]] then write /sys/kernel/debug/sched_features NEXT_BUDDY write /sys/kernel/debug/sched_features TTWU_QUEUE - write /sys/kernel/debug/sched_features HRTICK fi # CPU