On 3/19/26 14:12, Konstantin Khorenko wrote: > On 3/19/26 10:47, Dmitry Sepp wrote: >> The idea behind the change is to transition from the existing spatial >> vCPU handling approach that introduces costly modification to the >> scheduling logic to ensure the requested CPU count is obeyed (10%+ >> performance drop in some tests) to temporal isolation that can be >> provided by the cgroup2 cpu.max. >> >> Drop the legacy unneeded vCPU handling code. Remove the 'cpu.rate' >> control in favor of the internal calculation based on 'quota' and >> 'period' from 'cpu.max'. As 'cpu.max' is not implicitly used to set the >> rate, do not override nr_cpus when handling writes to 'cpu.max'. >> >> https://virtuozzo.atlassian.net/browse/VSTOR-124385 >> >> Signed-off-by: Dmitry Sepp <[email protected]> >> --- >> include/linux/sched.h | 6 - >> include/linux/sched/topology.h | 5 - >> kernel/sched/core.c | 98 +------- >> kernel/sched/fair.c | 408 --------------------------------- >> kernel/sched/sched.h | 10 - >> 5 files changed, 12 insertions(+), 515 deletions(-) >> > ... > >> -static int tg_set_cpu_limit(struct task_group *tg, >> - unsigned long cpu_rate, unsigned int nr_cpus) >> +static int tg_set_cpu_limit(struct task_group *tg, unsigned int nr_cpus) >> { >> int ret; >> unsigned long rate; >> + unsigned long cpu_rate = tg->cpu_rate; >> u64 quota = RUNTIME_INF; >> u64 burst = tg_get_cfs_burst(tg); >> u64 period = default_cfs_period(); >> @@ -10090,21 +10041,6 @@ static int tg_set_cpu_limit(struct task_group *tg, >> return ret; >> } >> > > static int tg_set_cpu_limit(struct task_group *tg, unsigned int nr_cpus) > { > int ret; > unsigned long rate; > unsigned long cpu_rate = tg->cpu_rate; > u64 quota = RUNTIME_INF; > u64 burst = tg_get_cfs_burst(tg); > u64 period = default_cfs_period(); > > rate = (cpu_rate && nr_cpus) ? > min_t(unsigned long, cpu_rate, nr_cpus * MAX_CPU_RATE) : > max_t(unsigned long, cpu_rate, nr_cpus * MAX_CPU_RATE); > if (rate) { > quota = div_u64(period * rate, MAX_CPU_RATE); > quota = max(quota, min_cfs_quota_period); > } > > cpus_read_lock(); > mutex_lock(&cfs_constraints_mutex); > ret = __tg_set_cfs_bandwidth(tg, period, quota, burst); > if (!ret) { > tg->cpu_rate = cpu_rate; > // the line above is a no-op. > // i will apply the patch as is but in case this was not intended, please fix > it with an incremental patch
We use ->cpu_rate in cpu_cgroup_update_vcpustat, should not it be updated to the value of rate here? > > > tg->nr_cpus = nr_cpus; > } > mutex_unlock(&cfs_constraints_mutex); > cpus_read_unlock(); > > return ret; > } -- Best regards, Pavel Tikhomirov Senior Software Developer, Virtuozzo. _______________________________________________ Devel mailing list [email protected] https://lists.openvz.org/mailman/listinfo/devel
