* [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
@ 2025-06-26 14:39 Chris Mason
2025-07-10 12:46 ` [tip: sched/core] sched/fair: Bump " tip-bot2 for Chris Mason
` (2 more replies)
0 siblings, 3 replies; 11+ messages in thread
From: Chris Mason @ 2025-06-26 14:39 UTC (permalink / raw)
To: peterz, vincent.guittot, linux-kernel; +Cc: Chris Mason
schbench (https://github.com/masoncl/schbench.git) is showing a
regression from previous production kernels that bisected down to:
sched/fair: Remove sysctl_sched_migration_cost condition (c5b0a7eefc)
The schbench command line was:
schbench -L -m 4 -M auto -t 256 -n 0 -r 0 -s 0
This creates 4 message threads pinned to CPUs 0-3, and 256x4 worker
threads spread across the rest of the CPUs. Neither the worker threads
or the message threads do any work, they just wake each other up and go
back to sleep as soon as possible.
The end result is the first 4 CPUs are pegged waking up those 1024
workers, and the rest of the CPUs are constantly banging in and out of
idle. If I take a v6.9 Linus kernel and revert that one commit,
performance goes from 3.4M RPS to 5.4M RPS.
schedstat shows there are ~100x more new idle balance operations, and
profiling shows the worker threads are spending ~20% of their CPU time
on new idle balance. schedstats also shows that almost all of these new
idle balance attemps are failing to find busy groups.
The fix used here is to crank up the cost of the newidle balance whenever it
fails. Since we don't want sd->max_newidle_lb_cost to grow out of
control, this also changes update_newidle_cost() to use
sysctl_sched_migration_cost as the upper limit on max_newidle_lb_cost.
Signed-off-by: Chris Mason <clm@fb.com>
---
kernel/sched/fair.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 7a14da5396fb2..042ab0863ccc0 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -12174,8 +12174,14 @@ static inline bool update_newidle_cost(struct sched_domain *sd, u64 cost)
/*
* Track max cost of a domain to make sure to not delay the
* next wakeup on the CPU.
+ *
+ * sched_balance_newidle() bumps the cost whenever newidle
+ * balance fails, and we don't want things to grow out of
+ * control. Use the sysctl_sched_migration_cost as the upper
+ * limit, plus a litle extra to avoid off by ones.
*/
- sd->max_newidle_lb_cost = cost;
+ sd->max_newidle_lb_cost =
+ min(cost, sysctl_sched_migration_cost + 200);
sd->last_decay_max_lb_cost = jiffies;
} else if (time_after(jiffies, sd->last_decay_max_lb_cost + HZ)) {
/*
@@ -12867,10 +12873,17 @@ static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf)
t1 = sched_clock_cpu(this_cpu);
domain_cost = t1 - t0;
- update_newidle_cost(sd, domain_cost);
-
curr_cost += domain_cost;
t0 = t1;
+
+ /*
+ * Failing newidle means it is not effective;
+ * bump the cost so we end up doing less of it.
+ */
+ if (!pulled_task)
+ domain_cost = (3 * sd->max_newidle_lb_cost) / 2;
+
+ update_newidle_cost(sd, domain_cost);
}
/*
--
2.47.1
^ permalink raw reply related [flat|nested] 11+ messages in thread* [tip: sched/core] sched/fair: Bump sd->max_newidle_lb_cost when newidle balance fails
2025-06-26 14:39 [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails Chris Mason
@ 2025-07-10 12:46 ` tip-bot2 for Chris Mason
2025-07-15 7:08 ` [PATCH v2] sched/fair: bump " kernel test robot
2025-09-07 18:21 ` Ryan Roberts
2 siblings, 0 replies; 11+ messages in thread
From: tip-bot2 for Chris Mason @ 2025-07-10 12:46 UTC (permalink / raw)
To: linux-tip-commits
Cc: Chris Mason, Peter Zijlstra (Intel), Vincent Guittot, x86,
linux-kernel
The following commit has been merged into the sched/core branch of tip:
Commit-ID: 155213a2aed42c85361bf4f5c817f5cb68951c3b
Gitweb: https://git.kernel.org/tip/155213a2aed42c85361bf4f5c817f5cb68951c3b
Author: Chris Mason <clm@fb.com>
AuthorDate: Thu, 26 Jun 2025 07:39:10 -07:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 09 Jul 2025 13:40:21 +02:00
sched/fair: Bump sd->max_newidle_lb_cost when newidle balance fails
schbench (https://github.com/masoncl/schbench.git) is showing a
regression from previous production kernels that bisected down to:
sched/fair: Remove sysctl_sched_migration_cost condition (c5b0a7eefc)
The schbench command line was:
schbench -L -m 4 -M auto -t 256 -n 0 -r 0 -s 0
This creates 4 message threads pinned to CPUs 0-3, and 256x4 worker
threads spread across the rest of the CPUs. Neither the worker threads
or the message threads do any work, they just wake each other up and go
back to sleep as soon as possible.
The end result is the first 4 CPUs are pegged waking up those 1024
workers, and the rest of the CPUs are constantly banging in and out of
idle. If I take a v6.9 Linus kernel and revert that one commit,
performance goes from 3.4M RPS to 5.4M RPS.
schedstat shows there are ~100x more new idle balance operations, and
profiling shows the worker threads are spending ~20% of their CPU time
on new idle balance. schedstats also shows that almost all of these new
idle balance attemps are failing to find busy groups.
The fix used here is to crank up the cost of the newidle balance whenever it
fails. Since we don't want sd->max_newidle_lb_cost to grow out of
control, this also changes update_newidle_cost() to use
sysctl_sched_migration_cost as the upper limit on max_newidle_lb_cost.
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20250626144017.1510594-2-clm@fb.com
---
kernel/sched/fair.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 7e2963e..ab0822c 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -12064,8 +12064,14 @@ static inline bool update_newidle_cost(struct sched_domain *sd, u64 cost)
/*
* Track max cost of a domain to make sure to not delay the
* next wakeup on the CPU.
+ *
+ * sched_balance_newidle() bumps the cost whenever newidle
+ * balance fails, and we don't want things to grow out of
+ * control. Use the sysctl_sched_migration_cost as the upper
+ * limit, plus a litle extra to avoid off by ones.
*/
- sd->max_newidle_lb_cost = cost;
+ sd->max_newidle_lb_cost =
+ min(cost, sysctl_sched_migration_cost + 200);
sd->last_decay_max_lb_cost = jiffies;
} else if (time_after(jiffies, sd->last_decay_max_lb_cost + HZ)) {
/*
@@ -12757,10 +12763,17 @@ static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf)
t1 = sched_clock_cpu(this_cpu);
domain_cost = t1 - t0;
- update_newidle_cost(sd, domain_cost);
-
curr_cost += domain_cost;
t0 = t1;
+
+ /*
+ * Failing newidle means it is not effective;
+ * bump the cost so we end up doing less of it.
+ */
+ if (!pulled_task)
+ domain_cost = (3 * sd->max_newidle_lb_cost) / 2;
+
+ update_newidle_cost(sd, domain_cost);
}
/*
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
2025-06-26 14:39 [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails Chris Mason
2025-07-10 12:46 ` [tip: sched/core] sched/fair: Bump " tip-bot2 for Chris Mason
@ 2025-07-15 7:08 ` kernel test robot
2025-07-15 10:08 ` Chen, Yu C
2025-09-07 18:21 ` Ryan Roberts
2 siblings, 1 reply; 11+ messages in thread
From: kernel test robot @ 2025-07-15 7:08 UTC (permalink / raw)
To: Chris Mason
Cc: oe-lkp, lkp, linux-kernel, aubrey.li, yu.c.chen, peterz,
vincent.guittot, Chris Mason, oliver.sang
Hello,
kernel test robot noticed a 22.9% regression of unixbench.throughput on:
commit: ac34cb39e8aea9915ec2f4e08c979eb2ed1d7561 ("[PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails")
url: https://github.com/intel-lab-lkp/linux/commits/Chris-Mason/sched-fair-bump-sd-max_newidle_lb_cost-when-newidle-balance-fails/20250626-224805
base: https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git 5bc34be478d09c4d16009e665e020ad0fcd0deea
patch link: https://lore.kernel.org/all/20250626144017.1510594-2-clm@fb.com/
patch subject: [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
testcase: unixbench
config: x86_64-rhel-9.4
compiler: gcc-12
test machine: 64 threads 2 sockets Intel(R) Xeon(R) Gold 6346 CPU @ 3.10GHz (Ice Lake) with 256G memory
parameters:
runtime: 300s
nr_task: 100%
test: shell1
cpufreq_governor: performance
In addition to that, the commit also has significant impact on the following tests:
+------------------+-------------------------------------------------------------------------------------------+
| testcase: change | unixbench: unixbench.throughput 20.3% regression |
| test machine | 64 threads 2 sockets Intel(R) Xeon(R) Gold 6346 CPU @ 3.10GHz (Ice Lake) with 256G memory |
| test parameters | cpufreq_governor=performance |
| | nr_task=100% |
| | runtime=300s |
| | test=shell16 |
+------------------+-------------------------------------------------------------------------------------------+
| testcase: change | unixbench: unixbench.throughput 26.2% regression |
| test machine | 64 threads 2 sockets Intel(R) Xeon(R) Gold 6346 CPU @ 3.10GHz (Ice Lake) with 256G memory |
| test parameters | cpufreq_governor=performance |
| | nr_task=100% |
| | runtime=300s |
| | test=shell8 |
+------------------+-------------------------------------------------------------------------------------------+
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202507150846.538fc133-lkp@intel.com
Details are as below:
-------------------------------------------------------------------------------------------------->
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20250715/202507150846.538fc133-lkp@intel.com
=========================================================================================
compiler/cpufreq_governor/kconfig/nr_task/rootfs/runtime/tbox_group/test/testcase:
gcc-12/performance/x86_64-rhel-9.4/100%/debian-12-x86_64-20240206.cgz/300s/lkp-icl-2sp9/shell1/unixbench
commit:
5bc34be478 ("sched/core: Reorganize cgroup bandwidth control interface file writes")
ac34cb39e8 ("sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails")
5bc34be478d09c4d ac34cb39e8aea9915ec2f4e08c9
---------------- ---------------------------
%stddev %change %stddev
\ | \
17957 +38.8% 24925 uptime.idle
1.611e+10 +42.4% 2.294e+10 cpuidle..time
2.162e+08 -23.9% 1.645e+08 cpuidle..usage
5.364e+08 -22.9% 4.134e+08 numa-numastat.node0.local_node
5.365e+08 -22.9% 4.134e+08 numa-numastat.node0.numa_hit
5.321e+08 -22.5% 4.123e+08 numa-numastat.node1.local_node
5.322e+08 -22.5% 4.124e+08 numa-numastat.node1.numa_hit
40.56 +41.4% 57.37 vmstat.cpu.id
39.90 -18.3% 32.60 ± 2% vmstat.procs.r
656646 -33.9% 434227 vmstat.system.cs
507937 -33.5% 337601 vmstat.system.in
3297469 -12.5% 2885290 meminfo.Active
3297469 -12.5% 2885290 meminfo.Active(anon)
3783682 -11.1% 3363144 meminfo.Committed_AS
126051 -11.5% 111597 meminfo.Mapped
2552513 -16.2% 2139559 meminfo.Shmem
4145 -23.5% 3170 perf-c2c.DRAM.local
27214 -28.6% 19429 perf-c2c.DRAM.remote
24159 -28.8% 17197 perf-c2c.HITM.local
17694 -26.7% 12972 perf-c2c.HITM.remote
41854 -27.9% 30169 perf-c2c.HITM.total
1433827 ± 13% -29.7% 1008553 ± 19% numa-meminfo.node0.Active
1433827 ± 13% -29.7% 1008553 ± 19% numa-meminfo.node0.Active(anon)
1021730 ± 13% -22.2% 794603 ± 18% numa-meminfo.node0.Shmem
1234989 ±124% +101.0% 2482483 ± 61% numa-meminfo.node0.Unevictable
178184 ± 52% +99.6% 355743 ± 23% numa-meminfo.node1.AnonHugePages
84396 ± 39% -42.8% 48315 ± 66% numa-meminfo.node1.Mapped
40.37 +16.9 57.24 mpstat.cpu.all.idle%
0.00 ± 9% +0.0 0.01 ± 6% mpstat.cpu.all.iowait%
1.38 -0.5 0.88 mpstat.cpu.all.irq%
0.63 -0.2 0.48 mpstat.cpu.all.soft%
48.87 -13.4 35.42 mpstat.cpu.all.sys%
8.74 -2.8 5.97 mpstat.cpu.all.usr%
64.36 -26.3% 47.43 mpstat.max_utilization_pct
35159 -22.9% 27105 unixbench.score
149076 -22.9% 114925 unixbench.throughput
11331167 -24.6% 8538458 unixbench.time.involuntary_context_switches
490074 -27.8% 354007 unixbench.time.major_page_faults
1.283e+09 -22.7% 9.909e+08 unixbench.time.minor_page_faults
3528 -23.9% 2683 unixbench.time.percent_of_cpu_this_job_got
16912 -23.8% 12883 unixbench.time.system_time
5340 -24.3% 4044 unixbench.time.user_time
1.994e+08 -34.0% 1.316e+08 unixbench.time.voluntary_context_switches
94067103 -23.0% 72441376 unixbench.workload
358475 ± 13% -29.7% 252168 ± 19% numa-vmstat.node0.nr_active_anon
255426 ± 13% -22.2% 198657 ± 18% numa-vmstat.node0.nr_shmem
308748 ±124% +101.0% 620615 ± 61% numa-vmstat.node0.nr_unevictable
358475 ± 13% -29.7% 252168 ± 19% numa-vmstat.node0.nr_zone_active_anon
308748 ±124% +101.0% 620615 ± 61% numa-vmstat.node0.nr_zone_unevictable
5.364e+08 -22.9% 4.134e+08 numa-vmstat.node0.numa_hit
5.364e+08 -22.9% 4.134e+08 numa-vmstat.node0.numa_local
86.96 ± 52% +99.8% 173.71 ± 23% numa-vmstat.node1.nr_anon_transparent_hugepages
20975 ± 39% -44.2% 11702 ± 69% numa-vmstat.node1.nr_mapped
5.321e+08 -22.5% 4.124e+08 numa-vmstat.node1.numa_hit
5.32e+08 -22.5% 4.123e+08 numa-vmstat.node1.numa_local
824471 -12.5% 721377 proc-vmstat.nr_active_anon
1544907 -6.7% 1441463 proc-vmstat.nr_file_pages
31890 -12.0% 28063 proc-vmstat.nr_mapped
15586 -6.0% 14654 proc-vmstat.nr_page_table_pages
638158 -16.2% 534927 proc-vmstat.nr_shmem
27700 -2.7% 26944 proc-vmstat.nr_slab_reclaimable
46384 -1.3% 45766 proc-vmstat.nr_slab_unreclaimable
824471 -12.5% 721377 proc-vmstat.nr_zone_active_anon
1.069e+09 -22.7% 8.258e+08 proc-vmstat.numa_hit
1.068e+09 -22.7% 8.257e+08 proc-vmstat.numa_local
1.097e+09 -22.7% 8.475e+08 proc-vmstat.pgalloc_normal
1.285e+09 -22.7% 9.935e+08 proc-vmstat.pgfault
1.096e+09 -22.7% 8.469e+08 proc-vmstat.pgfree
62443782 -22.9% 48142857 proc-vmstat.pgreuse
49314 -22.7% 38119 proc-vmstat.thp_fault_alloc
20703487 -23.0% 15951229 proc-vmstat.unevictable_pgs_culled
3.31 -13.5% 2.87 perf-stat.i.MPKI
1.573e+10 -26.9% 1.151e+10 perf-stat.i.branch-instructions
1.65 -0.1 1.51 perf-stat.i.branch-miss-rate%
2.56e+08 -33.3% 1.708e+08 perf-stat.i.branch-misses
21.13 +1.0 22.10 perf-stat.i.cache-miss-rate%
2.564e+08 -37.0% 1.616e+08 perf-stat.i.cache-misses
1.2e+09 -39.8% 7.221e+08 perf-stat.i.cache-references
659355 -33.9% 436041 perf-stat.i.context-switches
1.88 -1.1% 1.85 perf-stat.i.cpi
1.451e+11 -27.8% 1.048e+11 perf-stat.i.cpu-cycles
166359 -50.8% 81842 perf-stat.i.cpu-migrations
572.23 +14.0% 652.16 perf-stat.i.cycles-between-cache-misses
7.632e+10 -26.9% 5.58e+10 perf-stat.i.instructions
776.76 -27.7% 561.23 perf-stat.i.major-faults
75.15 -25.2% 56.20 perf-stat.i.metric.K/sec
1992430 -22.7% 1540174 perf-stat.i.minor-faults
1993207 -22.7% 1540736 perf-stat.i.page-faults
3.36 -13.8% 2.90 perf-stat.overall.MPKI
1.63 -0.1 1.48 perf-stat.overall.branch-miss-rate%
21.36 +1.0 22.38 perf-stat.overall.cache-miss-rate%
1.90 -1.2% 1.88 perf-stat.overall.cpi
565.86 +14.6% 648.44 perf-stat.overall.cycles-between-cache-misses
511627 -5.0% 486061 perf-stat.overall.path-length
1.571e+10 -26.9% 1.149e+10 perf-stat.ps.branch-instructions
2.557e+08 -33.3% 1.705e+08 perf-stat.ps.branch-misses
2.56e+08 -37.0% 1.613e+08 perf-stat.ps.cache-misses
1.198e+09 -39.8% 7.21e+08 perf-stat.ps.cache-references
658326 -33.9% 435320 perf-stat.ps.context-switches
1.448e+11 -27.8% 1.046e+11 perf-stat.ps.cpu-cycles
166110 -50.8% 81714 perf-stat.ps.cpu-migrations
7.621e+10 -26.9% 5.571e+10 perf-stat.ps.instructions
775.68 -27.8% 560.36 perf-stat.ps.major-faults
1989394 -22.7% 1537634 perf-stat.ps.minor-faults
1990170 -22.7% 1538194 perf-stat.ps.page-faults
4.813e+13 -26.8% 3.521e+13 perf-stat.total.instructions
12366538 -24.1% 9391151 sched_debug.cfs_rq:/.avg_vruntime.avg
13881097 -25.9% 10292721 ± 3% sched_debug.cfs_rq:/.avg_vruntime.max
12094177 -24.3% 9151437 sched_debug.cfs_rq:/.avg_vruntime.min
0.61 ± 4% -19.8% 0.49 ± 6% sched_debug.cfs_rq:/.h_nr_queued.avg
0.59 ± 3% +11.0% 0.66 ± 4% sched_debug.cfs_rq:/.h_nr_queued.stddev
0.60 ± 4% -20.7% 0.47 ± 5% sched_debug.cfs_rq:/.h_nr_runnable.avg
0.57 ± 3% +9.8% 0.63 ± 4% sched_debug.cfs_rq:/.h_nr_runnable.stddev
285550 ± 26% -49.0% 145513 ± 43% sched_debug.cfs_rq:/.left_deadline.avg
9795386 ± 16% -40.2% 5855585 ± 35% sched_debug.cfs_rq:/.left_deadline.max
1571799 ± 18% -43.3% 890472 ± 38% sched_debug.cfs_rq:/.left_deadline.stddev
285548 ± 26% -49.0% 145511 ± 43% sched_debug.cfs_rq:/.left_vruntime.avg
9795302 ± 16% -40.2% 5855509 ± 35% sched_debug.cfs_rq:/.left_vruntime.max
1571785 ± 18% -43.3% 890461 ± 38% sched_debug.cfs_rq:/.left_vruntime.stddev
13.95 ± 3% -26.3% 10.29 ± 3% sched_debug.cfs_rq:/.load_avg.min
12366538 -24.1% 9391151 sched_debug.cfs_rq:/.min_vruntime.avg
13881097 -25.9% 10292721 ± 3% sched_debug.cfs_rq:/.min_vruntime.max
12094177 -24.3% 9151438 sched_debug.cfs_rq:/.min_vruntime.min
0.56 ± 3% -26.4% 0.41 ± 4% sched_debug.cfs_rq:/.nr_queued.avg
33.15 ± 15% +46.7% 48.63 ± 24% sched_debug.cfs_rq:/.removed.load_avg.avg
149.93 ± 9% +24.8% 187.17 ± 14% sched_debug.cfs_rq:/.removed.load_avg.stddev
285548 ± 26% -49.0% 145511 ± 43% sched_debug.cfs_rq:/.right_vruntime.avg
9795302 ± 16% -40.2% 5855509 ± 35% sched_debug.cfs_rq:/.right_vruntime.max
1571785 ± 18% -43.3% 890461 ± 38% sched_debug.cfs_rq:/.right_vruntime.stddev
1520 ± 5% -9.4% 1378 ± 3% sched_debug.cfs_rq:/.runnable_avg.max
1524 ± 4% -9.8% 1375 ± 3% sched_debug.cfs_rq:/.util_avg.max
89.85 ± 5% -19.7% 72.13 ± 6% sched_debug.cfs_rq:/.util_est.avg
151069 +75.1% 264508 ± 3% sched_debug.cpu.avg_idle.avg
305891 ± 7% +93.0% 590328 ± 9% sched_debug.cpu.avg_idle.max
33491 ± 12% +96.0% 65650 ± 14% sched_debug.cpu.avg_idle.min
53210 ± 4% +102.6% 107782 ± 7% sched_debug.cpu.avg_idle.stddev
1051570 ± 7% -30.7% 728706 ± 8% sched_debug.cpu.curr->pid.avg
500485 +182.2% 1412208 sched_debug.cpu.max_idle_balance_cost.avg
516654 +188.9% 1492616 sched_debug.cpu.max_idle_balance_cost.max
500000 +166.3% 1331544 sched_debug.cpu.max_idle_balance_cost.min
2516 ± 29% +1714.3% 45656 ± 5% sched_debug.cpu.max_idle_balance_cost.stddev
0.60 ± 3% -19.8% 0.48 ± 5% sched_debug.cpu.nr_running.avg
0.59 ± 2% +12.1% 0.66 ± 5% sched_debug.cpu.nr_running.stddev
3086131 -33.6% 2048649 sched_debug.cpu.nr_switches.avg
3157114 -34.1% 2079849 sched_debug.cpu.nr_switches.max
2903213 -31.5% 1988842 sched_debug.cpu.nr_switches.min
42830 ± 15% -59.8% 17196 ± 16% sched_debug.cpu.nr_switches.stddev
0.74 ± 5% +15.5% 0.85 ± 3% sched_debug.cpu.nr_uninterruptible.avg
13734 ± 28% -74.1% 3553 ± 11% sched_debug.cpu.nr_uninterruptible.max
-26136 -85.3% -3833 sched_debug.cpu.nr_uninterruptible.min
8461 ± 24% -79.9% 1701 ± 10% sched_debug.cpu.nr_uninterruptible.stddev
0.01 ± 12% +66.2% 0.02 ± 25% perf-sched.sch_delay.avg.ms.__cond_resched.__alloc_frozen_pages_noprof.alloc_pages_mpol.vma_alloc_folio_noprof.wp_page_copy
0.01 ± 32% +224.1% 0.04 ± 46% perf-sched.sch_delay.avg.ms.__cond_resched.__do_fault.do_read_fault.do_pte_missing.__handle_mm_fault
0.01 ± 7% +86.7% 0.03 ± 27% perf-sched.sch_delay.avg.ms.__cond_resched.__tlb_batch_free_encoded_pages.tlb_finish_mmu.exit_mmap.__mmput
0.02 ± 48% +184.5% 0.05 ± 39% perf-sched.sch_delay.avg.ms.__cond_resched.__tlb_batch_free_encoded_pages.tlb_finish_mmu.vms_clear_ptes.part
0.01 ± 20% +48.4% 0.01 ± 9% perf-sched.sch_delay.avg.ms.__cond_resched.copy_strings.isra.0.do_execveat_common
0.01 ± 45% +244.6% 0.05 ± 43% perf-sched.sch_delay.avg.ms.__cond_resched.do_close_on_exec.begin_new_exec.load_elf_binary.exec_binprm
0.01 ± 11% +46.9% 0.02 ± 6% perf-sched.sch_delay.avg.ms.__cond_resched.down_read.walk_component.link_path_walk.path_openat
0.02 ± 28% +90.0% 0.03 ± 25% perf-sched.sch_delay.avg.ms.__cond_resched.down_read.walk_component.path_lookupat.filename_lookup
0.01 ± 22% +47.7% 0.02 ± 21% perf-sched.sch_delay.avg.ms.__cond_resched.down_write.unlink_anon_vmas.free_pgtables.exit_mmap
0.01 ± 22% +135.1% 0.03 ± 24% perf-sched.sch_delay.avg.ms.__cond_resched.down_write_killable.setup_arg_pages.load_elf_binary.exec_binprm
0.02 ± 56% +233.7% 0.05 ± 39% perf-sched.sch_delay.avg.ms.__cond_resched.down_write_killable.vm_mmap_pgoff.do_syscall_64.entry_SYSCALL_64_after_hwframe
0.01 ± 20% +122.8% 0.03 ± 25% perf-sched.sch_delay.avg.ms.__cond_resched.down_write_killable.vm_mmap_pgoff.elf_load.load_elf_binary
0.01 ± 16% +93.4% 0.02 ± 28% perf-sched.sch_delay.avg.ms.__cond_resched.dput.step_into.path_lookupat.filename_lookup
0.01 ± 7% +22.2% 0.01 ± 8% perf-sched.sch_delay.avg.ms.__cond_resched.dput.terminate_walk.path_openat.do_filp_open
0.01 ± 27% +127.0% 0.02 ± 37% perf-sched.sch_delay.avg.ms.__cond_resched.exit_mmap.__mmput.exit_mm.do_exit
0.01 ± 30% +88.2% 0.03 ± 24% perf-sched.sch_delay.avg.ms.__cond_resched.kmem_cache_alloc_lru_noprof.__d_alloc.d_alloc.d_alloc_parallel
0.01 ± 24% +79.7% 0.02 ± 27% perf-sched.sch_delay.avg.ms.__cond_resched.kmem_cache_alloc_noprof.vm_area_alloc._install_special_mapping.map_vdso
0.05 ±125% -89.1% 0.01 ± 28% perf-sched.sch_delay.avg.ms.__cond_resched.mmput.exit_mm.do_exit.do_group_exit
0.01 ± 21% -74.4% 0.00 ±145% perf-sched.sch_delay.avg.ms.__cond_resched.mutex_lock.uprobe_clear_state.__mmput.exit_mm
0.01 ± 43% +184.3% 0.04 ± 49% perf-sched.sch_delay.avg.ms.__cond_resched.remove_vma.vms_complete_munmap_vmas.__mmap_region.do_mmap
0.01 +97.9% 0.02 ± 2% perf-sched.sch_delay.avg.ms.__cond_resched.stop_one_cpu.sched_exec.bprm_execve.part
0.01 ± 6% +151.4% 0.03 ± 59% perf-sched.sch_delay.avg.ms.__cond_resched.zap_pte_range.zap_pmd_range.isra.0
0.02 ± 2% +18.9% 0.02 ± 4% perf-sched.sch_delay.avg.ms.do_wait.kernel_wait4.do_syscall_64.entry_SYSCALL_64_after_hwframe
0.01 ± 10% +42.4% 0.02 ± 14% perf-sched.sch_delay.avg.ms.exit_to_user_mode_loop.do_syscall_64.entry_SYSCALL_64_after_hwframe.[unknown]
0.01 ± 9% +73.3% 0.02 ± 23% perf-sched.sch_delay.avg.ms.io_schedule.folio_wait_bit_common.__do_fault.do_read_fault
0.01 ± 4% +26.2% 0.02 ± 4% perf-sched.sch_delay.avg.ms.io_schedule.folio_wait_bit_common.filemap_fault.__do_fault
0.01 ± 13% +68.8% 0.02 ± 2% perf-sched.sch_delay.avg.ms.irqentry_exit_to_user_mode.asm_exc_page_fault.[unknown]
0.02 ± 5% +72.6% 0.03 ± 2% perf-sched.sch_delay.avg.ms.irqentry_exit_to_user_mode.asm_exc_page_fault.[unknown].[unknown]
0.01 ± 12% +45.8% 0.01 ± 14% perf-sched.sch_delay.avg.ms.irqentry_exit_to_user_mode.asm_sysvec_apic_timer_interrupt.[unknown]
0.01 ± 6% +42.6% 0.01 ± 6% perf-sched.sch_delay.avg.ms.irqentry_exit_to_user_mode.asm_sysvec_apic_timer_interrupt.[unknown].[unknown]
0.04 ± 21% +106.5% 0.07 ± 8% perf-sched.sch_delay.avg.ms.irqentry_exit_to_user_mode.asm_sysvec_reschedule_ipi.[unknown]
0.04 ± 15% +120.5% 0.10 ± 15% perf-sched.sch_delay.avg.ms.irqentry_exit_to_user_mode.asm_sysvec_reschedule_ipi.[unknown].[unknown]
0.01 ± 3% +24.6% 0.01 ± 5% perf-sched.sch_delay.avg.ms.schedule_preempt_disabled.rwsem_down_read_slowpath.down_read.open_last_lookups
0.01 ± 3% +50.8% 0.02 ± 2% perf-sched.sch_delay.avg.ms.schedule_preempt_disabled.rwsem_down_read_slowpath.down_read.walk_component
0.01 ± 5% +31.4% 0.01 ± 3% perf-sched.sch_delay.avg.ms.schedule_preempt_disabled.rwsem_down_write_slowpath.down_write.open_last_lookups
0.02 ± 7% -18.2% 0.01 ± 11% perf-sched.sch_delay.avg.ms.schedule_timeout.__wait_for_common.stop_one_cpu.sched_exec
0.01 ± 10% +40.2% 0.02 ± 6% perf-sched.sch_delay.avg.ms.schedule_timeout.__wait_for_common.wait_for_completion_state.kernel_clone
0.01 ± 6% +29.9% 0.02 ± 6% perf-sched.sch_delay.avg.ms.sigsuspend.__x64_sys_rt_sigsuspend.do_syscall_64.entry_SYSCALL_64_after_hwframe
0.01 -12.5% 0.01 perf-sched.sch_delay.avg.ms.smpboot_thread_fn.kthread.ret_from_fork.ret_from_fork_asm
0.03 ± 3% -16.9% 0.02 ± 3% perf-sched.sch_delay.avg.ms.worker_thread.kthread.ret_from_fork.ret_from_fork_asm
0.11 ± 52% +316.2% 0.47 ± 74% perf-sched.sch_delay.max.ms.__cond_resched.__alloc_frozen_pages_noprof.alloc_pages_mpol.alloc_pages_noprof.__pud_alloc
0.12 ± 41% +85.8% 0.22 ± 32% perf-sched.sch_delay.max.ms.__cond_resched.copy_strings.isra.0.do_execveat_common
0.10 ± 58% +298.3% 0.42 ± 65% perf-sched.sch_delay.max.ms.__cond_resched.do_close_on_exec.begin_new_exec.load_elf_binary.exec_binprm
0.07 ± 80% +633.0% 0.50 ± 90% perf-sched.sch_delay.max.ms.__cond_resched.down_write.unlink_file_vma_batch_process.unlink_file_vma_batch_add.free_pgtables
0.11 ± 44% +108.8% 0.22 ± 39% perf-sched.sch_delay.max.ms.__cond_resched.down_write_killable.exec_mmap.begin_new_exec.load_elf_binary
0.11 ± 34% +478.5% 0.65 ± 64% perf-sched.sch_delay.max.ms.__cond_resched.down_write_killable.setup_arg_pages.load_elf_binary.exec_binprm
0.09 ± 65% +286.6% 0.34 ± 69% perf-sched.sch_delay.max.ms.__cond_resched.down_write_killable.vm_mmap_pgoff.do_syscall_64.entry_SYSCALL_64_after_hwframe
0.12 ± 24% +313.1% 0.49 ± 54% perf-sched.sch_delay.max.ms.__cond_resched.down_write_killable.vm_mmap_pgoff.elf_load.load_elf_binary
0.10 ± 32% +185.2% 0.29 ± 57% perf-sched.sch_delay.max.ms.__cond_resched.kmem_cache_alloc_noprof.vm_area_alloc._install_special_mapping.map_vdso
0.09 ± 27% +142.0% 0.23 ± 25% perf-sched.sch_delay.max.ms.__cond_resched.mmput.exec_mmap.begin_new_exec.load_elf_binary
0.15 ±147% -95.7% 0.01 ± 29% perf-sched.sch_delay.max.ms.__cond_resched.mmput.exit_mm.do_exit.do_group_exit
0.01 ± 20% -75.0% 0.00 ±145% perf-sched.sch_delay.max.ms.__cond_resched.mutex_lock.uprobe_clear_state.__mmput.exit_mm
0.15 ± 50% +388.7% 0.71 ± 68% perf-sched.sch_delay.max.ms.__cond_resched.remove_vma.vms_complete_munmap_vmas.__mmap_region.do_mmap
0.40 ± 27% +1421.1% 6.14 ±174% perf-sched.sch_delay.max.ms.__cond_resched.zap_pte_range.zap_pmd_range.isra.0
0.07 ± 30% +303.5% 0.27 ± 45% perf-sched.sch_delay.max.ms.do_task_dead.do_exit.do_group_exit.__x64_sys_exit_group.x64_sys_call
0.11 ± 44% +107.0% 0.24 ± 31% perf-sched.sch_delay.max.ms.io_schedule.folio_wait_bit_common.__do_fault.do_read_fault
0.97 ± 36% +177.9% 2.69 ± 54% perf-sched.sch_delay.max.ms.irqentry_exit_to_user_mode.asm_exc_page_fault.[unknown].[unknown]
0.85 ± 41% +92.2% 1.63 ± 24% perf-sched.sch_delay.max.ms.irqentry_exit_to_user_mode.asm_sysvec_apic_timer_interrupt.[unknown]
0.15 ±108% -80.7% 0.03 ± 99% perf-sched.sch_delay.max.ms.irqentry_exit_to_user_mode.asm_sysvec_call_function_single.[unknown].[unknown]
0.36 ± 41% +123.0% 0.80 ± 40% perf-sched.sch_delay.max.ms.irqentry_exit_to_user_mode.asm_sysvec_reschedule_ipi.[unknown]
0.05 ± 28% -34.7% 0.03 ± 27% perf-sched.sch_delay.max.ms.schedule_timeout.__wait_for_common.stop_one_cpu.sched_exec
0.01 ± 3% +38.5% 0.02 perf-sched.total_sch_delay.average.ms
1.01 +18.4% 1.19 perf-sched.total_wait_and_delay.average.ms
1887109 -14.5% 1613345 perf-sched.total_wait_and_delay.count.ms
1.00 +18.1% 1.18 perf-sched.total_wait_time.average.ms
13.85 ± 15% +37.4% 19.02 ± 17% perf-sched.wait_and_delay.avg.ms.__cond_resched.generic_perform_write.shmem_file_write_iter.vfs_write.ksys_write
6.31 +17.3% 7.41 perf-sched.wait_and_delay.avg.ms.__cond_resched.smpboot_thread_fn.kthread.ret_from_fork.ret_from_fork_asm
0.06 +57.6% 0.09 perf-sched.wait_and_delay.avg.ms.__cond_resched.stop_one_cpu.sched_exec.bprm_execve.part
0.59 +16.4% 0.69 perf-sched.wait_and_delay.avg.ms.anon_pipe_read.vfs_read.ksys_read.do_syscall_64
0.02 ± 2% +191.4% 0.05 perf-sched.wait_and_delay.avg.ms.do_task_dead.do_exit.do_group_exit.__x64_sys_exit_group.x64_sys_call
5.95 +11.0% 6.61 perf-sched.wait_and_delay.avg.ms.do_wait.kernel_wait4.do_syscall_64.entry_SYSCALL_64_after_hwframe
19.94 ± 4% +12.3% 22.39 perf-sched.wait_and_delay.avg.ms.schedule_hrtimeout_range_clock.poll_schedule_timeout.constprop.0.do_poll
0.22 +28.1% 0.29 perf-sched.wait_and_delay.avg.ms.schedule_preempt_disabled.rwsem_down_read_slowpath.down_read.open_last_lookups
0.21 +24.9% 0.27 perf-sched.wait_and_delay.avg.ms.schedule_preempt_disabled.rwsem_down_read_slowpath.down_read.walk_component
0.21 +20.4% 0.25 perf-sched.wait_and_delay.avg.ms.schedule_preempt_disabled.rwsem_down_write_slowpath.down_write.do_unlinkat
0.14 +27.0% 0.17 perf-sched.wait_and_delay.avg.ms.schedule_preempt_disabled.rwsem_down_write_slowpath.down_write.open_last_lookups
0.54 ± 2% +28.7% 0.70 perf-sched.wait_and_delay.avg.ms.schedule_timeout.__wait_for_common.wait_for_completion_state.kernel_clone
0.22 ± 3% +22.0% 0.27 ± 3% perf-sched.wait_and_delay.avg.ms.sigsuspend.__x64_sys_rt_sigsuspend.do_syscall_64.entry_SYSCALL_64_after_hwframe
7.32 +13.4% 8.30 perf-sched.wait_and_delay.avg.ms.smpboot_thread_fn.kthread.ret_from_fork.ret_from_fork_asm
126.17 ± 8% -19.8% 101.17 ± 7% perf-sched.wait_and_delay.count.__cond_resched.__alloc_frozen_pages_noprof.alloc_pages_mpol.alloc_pages_noprof.pte_alloc_one
10.50 ± 25% -54.0% 4.83 ± 73% perf-sched.wait_and_delay.count.__cond_resched.__kmalloc_node_noprof.__vmalloc_area_node.__vmalloc_node_range_noprof.__vmalloc_node_noprof
537.33 ± 2% -22.5% 416.33 perf-sched.wait_and_delay.count.__cond_resched.__tlb_batch_free_encoded_pages.tlb_finish_mmu.exit_mmap.__mmput
43.00 ± 6% -29.8% 30.17 ± 15% perf-sched.wait_and_delay.count.__cond_resched.cgroup_css_set_fork.cgroup_can_fork.copy_process.kernel_clone
80.50 ± 7% -32.1% 54.67 ± 4% perf-sched.wait_and_delay.count.__cond_resched.copy_page_range.dup_mmap.dup_mm.constprop
126.33 ± 10% -21.4% 99.33 ± 8% perf-sched.wait_and_delay.count.__cond_resched.copy_pte_range.copy_p4d_range.copy_page_range.dup_mmap
46.83 ± 9% -18.9% 38.00 ± 6% perf-sched.wait_and_delay.count.__cond_resched.down_write.anon_vma_clone.anon_vma_fork.dup_mmap
369.17 ± 5% -18.6% 300.50 ± 4% perf-sched.wait_and_delay.count.__cond_resched.down_write.unlink_anon_vmas.free_pgtables.exit_mmap
62.83 ± 9% -26.3% 46.33 ± 9% perf-sched.wait_and_delay.count.__cond_resched.exit_mmap.__mmput.exit_mm.do_exit
91.17 ± 5% -26.1% 67.33 ± 3% perf-sched.wait_and_delay.count.__cond_resched.generic_perform_write.shmem_file_write_iter.vfs_write.ksys_write
45.50 ± 16% -31.9% 31.00 ± 21% perf-sched.wait_and_delay.count.__cond_resched.kmem_cache_alloc_noprof.alloc_pid.copy_process.kernel_clone
67.50 ± 15% -26.9% 49.33 ± 8% perf-sched.wait_and_delay.count.__cond_resched.kmem_cache_alloc_noprof.prepare_creds.copy_creds.copy_process
183.83 ± 5% -28.6% 131.33 ± 6% perf-sched.wait_and_delay.count.__cond_resched.kmem_cache_alloc_noprof.vm_area_dup.dup_mmap.dup_mm
7.67 ± 16% -52.2% 3.67 ± 51% perf-sched.wait_and_delay.count.__cond_resched.mutex_lock.fdget_pos.ksys_write.do_syscall_64
93.50 ± 9% -30.3% 65.17 ± 45% perf-sched.wait_and_delay.count.__cond_resched.mutex_lock_killable.pcpu_alloc_noprof.__percpu_counter_init_many.mm_init
32.33 ± 13% -36.1% 20.67 ± 23% perf-sched.wait_and_delay.count.__cond_resched.pidfs_exit.release_task.wait_task_zombie.__do_wait
28.67 ± 11% -31.4% 19.67 ± 22% perf-sched.wait_and_delay.count.__cond_resched.shmem_inode_acct_blocks.shmem_alloc_and_add_folio.shmem_get_folio_gfp.shmem_write_begin
2932 ± 2% -15.8% 2468 ± 4% perf-sched.wait_and_delay.count.__cond_resched.smpboot_thread_fn.kthread.ret_from_fork.ret_from_fork_asm
43706 -10.1% 39295 perf-sched.wait_and_delay.count.__cond_resched.stop_one_cpu.sched_exec.bprm_execve.part
797.83 -20.7% 633.00 ± 2% perf-sched.wait_and_delay.count.__cond_resched.zap_pte_range.zap_pmd_range.isra.0
75849 -12.9% 66072 perf-sched.wait_and_delay.count.anon_pipe_read.vfs_read.ksys_read.do_syscall_64
97605 -10.0% 87867 perf-sched.wait_and_delay.count.do_task_dead.do_exit.do_group_exit.__x64_sys_exit_group.x64_sys_call
79047 -10.0% 71173 perf-sched.wait_and_delay.count.do_wait.kernel_wait4.do_syscall_64.entry_SYSCALL_64_after_hwframe
2304 ± 3% -14.0% 1980 ± 2% perf-sched.wait_and_delay.count.exit_to_user_mode_loop.do_syscall_64.entry_SYSCALL_64_after_hwframe.[unknown]
79568 -16.4% 66556 perf-sched.wait_and_delay.count.schedule_preempt_disabled.rwsem_down_read_slowpath.down_read.open_last_lookups
1246136 -15.5% 1052691 perf-sched.wait_and_delay.count.schedule_preempt_disabled.rwsem_down_read_slowpath.down_read.walk_component
21025 -14.7% 17931 perf-sched.wait_and_delay.count.schedule_preempt_disabled.rwsem_down_write_slowpath.down_write.do_unlinkat
21731 -10.0% 19563 perf-sched.wait_and_delay.count.schedule_timeout.__wait_for_common.wait_for_completion_state.kernel_clone
10842 -10.0% 9757 perf-sched.wait_and_delay.count.sigsuspend.__x64_sys_rt_sigsuspend.do_syscall_64.entry_SYSCALL_64_after_hwframe
83415 -11.7% 73668 perf-sched.wait_and_delay.count.smpboot_thread_fn.kthread.ret_from_fork.ret_from_fork_asm
19.70 ± 71% +75.6% 34.61 ± 6% perf-sched.wait_and_delay.max.ms.__cond_resched.__alloc_frozen_pages_noprof.alloc_pages_mpol.alloc_pages_noprof.pgd_alloc
34.37 ± 5% +14.7% 39.42 ± 3% perf-sched.wait_and_delay.max.ms.__cond_resched.copy_pte_range.copy_p4d_range.copy_page_range.dup_mmap
31.04 +10.8% 34.38 ± 4% perf-sched.wait_and_delay.max.ms.__cond_resched.down_write.unlink_anon_vmas.free_pgtables.exit_mmap
28.30 ± 4% +14.1% 32.30 ± 3% perf-sched.wait_and_delay.max.ms.__cond_resched.exit_mmap.__mmput.exit_mm.do_exit
22.54 ± 49% +59.0% 35.84 ± 6% perf-sched.wait_and_delay.max.ms.__cond_resched.kmem_cache_alloc_noprof.dup_fd.copy_process.kernel_clone
2.25 ± 30% +67.7% 3.77 ± 9% perf-sched.wait_and_delay.max.ms.__cond_resched.stop_one_cpu.sched_exec.bprm_execve.part
29.76 ± 8% +14.9% 34.19 ± 5% perf-sched.wait_and_delay.max.ms.__cond_resched.uprobe_start_dup_mmap.dup_mm.constprop.0
23.02 ± 45% +57.0% 36.15 ± 25% perf-sched.wait_and_delay.max.ms.__cond_resched.zap_pmd_range.isra.0.unmap_page_range
30.95 ± 2% +27.9% 39.60 ± 24% perf-sched.wait_and_delay.max.ms.__cond_resched.zap_pte_range.zap_pmd_range.isra.0
4.42 ± 19% +393.4% 21.82 ± 11% perf-sched.wait_and_delay.max.ms.do_task_dead.do_exit.do_group_exit.__x64_sys_exit_group.x64_sys_call
28.27 ± 4% +23.0% 34.76 ± 3% perf-sched.wait_and_delay.max.ms.sigsuspend.__x64_sys_rt_sigsuspend.do_syscall_64.entry_SYSCALL_64_after_hwframe
0.08 ± 11% +48.0% 0.12 ± 25% perf-sched.wait_time.avg.ms.__cond_resched.__anon_vma_prepare.__vmf_anon_prepare.do_pte_missing.__handle_mm_fault
0.15 ± 5% +13.9% 0.17 ± 4% perf-sched.wait_time.avg.ms.__cond_resched.__kmalloc_cache_noprof.perf_event_mmap_event.perf_event_mmap.__mmap_region
0.16 ± 9% +41.4% 0.23 ± 7% perf-sched.wait_time.avg.ms.__cond_resched.__tlb_batch_free_encoded_pages.tlb_finish_mmu.vms_clear_ptes.part
0.13 ± 22% +50.8% 0.19 ± 19% perf-sched.wait_time.avg.ms.__cond_resched.change_pmd_range.isra.0.change_pud_range
0.18 ± 4% +24.8% 0.22 ± 5% perf-sched.wait_time.avg.ms.__cond_resched.change_pud_range.isra.0.change_protection_range
0.08 ± 38% +99.8% 0.16 ± 30% perf-sched.wait_time.avg.ms.__cond_resched.do_close_on_exec.begin_new_exec.load_elf_binary.exec_binprm
0.18 ± 4% +20.1% 0.22 ± 2% perf-sched.wait_time.avg.ms.__cond_resched.down_read.open_last_lookups.path_openat.do_filp_open
0.20 ± 2% +22.5% 0.25 ± 7% perf-sched.wait_time.avg.ms.__cond_resched.down_read.walk_component.link_path_walk.path_lookupat
0.18 +19.3% 0.22 ± 3% perf-sched.wait_time.avg.ms.__cond_resched.down_read.walk_component.link_path_walk.path_openat
0.12 ± 9% +15.3% 0.14 ± 10% perf-sched.wait_time.avg.ms.__cond_resched.down_write.__mmap_new_vma.__mmap_region.do_mmap
0.20 ± 2% +25.7% 0.25 ± 8% perf-sched.wait_time.avg.ms.__cond_resched.down_write.vma_prepare.__split_vma.vma_modify
0.02 ± 42% +126.9% 0.04 ± 22% perf-sched.wait_time.avg.ms.__cond_resched.down_write_killable.setup_arg_pages.load_elf_binary.exec_binprm
0.19 +22.8% 0.24 ± 3% perf-sched.wait_time.avg.ms.__cond_resched.dput.d_alloc_parallel.__lookup_slow.walk_component
0.20 ± 4% +28.6% 0.25 ± 6% perf-sched.wait_time.avg.ms.__cond_resched.dput.open_last_lookups.path_openat.do_filp_open
0.21 ± 2% +24.4% 0.26 ± 7% perf-sched.wait_time.avg.ms.__cond_resched.dput.step_into.link_path_walk.path_lookupat
0.19 +16.6% 0.22 ± 2% perf-sched.wait_time.avg.ms.__cond_resched.dput.step_into.link_path_walk.path_openat
0.19 ± 5% +22.7% 0.24 ± 8% perf-sched.wait_time.avg.ms.__cond_resched.dput.step_into.open_last_lookups.path_openat
0.21 ± 6% +19.4% 0.25 ± 4% perf-sched.wait_time.avg.ms.__cond_resched.dput.terminate_walk.path_lookupat.filename_lookup
0.17 +22.6% 0.21 ± 3% perf-sched.wait_time.avg.ms.__cond_resched.dput.terminate_walk.path_openat.do_filp_open
0.03 ± 33% +85.9% 0.06 ± 29% perf-sched.wait_time.avg.ms.__cond_resched.filemap_read.__kernel_read.exec_binprm.bprm_execve
0.13 ± 15% +82.8% 0.24 ± 32% perf-sched.wait_time.avg.ms.__cond_resched.folio_zero_user.vma_alloc_anon_folio_pmd.__do_huge_pmd_anonymous_page.__handle_mm_fault
13.84 ± 15% +37.4% 19.02 ± 17% perf-sched.wait_time.avg.ms.__cond_resched.generic_perform_write.shmem_file_write_iter.vfs_write.ksys_write
0.20 ± 5% +23.4% 0.25 ± 10% perf-sched.wait_time.avg.ms.__cond_resched.kmem_cache_alloc_lru_noprof.__d_alloc.d_alloc.d_alloc_parallel
0.17 ± 5% +20.6% 0.20 ± 5% perf-sched.wait_time.avg.ms.__cond_resched.kmem_cache_alloc_noprof.vm_area_alloc.__mmap_new_vma.__mmap_region
0.21 ± 3% +15.2% 0.24 ± 4% perf-sched.wait_time.avg.ms.__cond_resched.kmem_cache_alloc_noprof.vm_area_dup.__split_vma.vms_gather_munmap_vmas
0.01 ± 86% +437.8% 0.07 ± 86% perf-sched.wait_time.avg.ms.__cond_resched.move_page_tables.relocate_vma_down.setup_arg_pages.load_elf_binary
0.20 ± 3% +35.3% 0.27 ± 11% perf-sched.wait_time.avg.ms.__cond_resched.remove_vma.vms_complete_munmap_vmas.__mmap_region.do_mmap
6.30 +17.3% 7.40 perf-sched.wait_time.avg.ms.__cond_resched.smpboot_thread_fn.kthread.ret_from_fork.ret_from_fork_asm
0.05 +50.9% 0.07 perf-sched.wait_time.avg.ms.__cond_resched.stop_one_cpu.sched_exec.bprm_execve.part
0.20 ± 2% +23.0% 0.24 ± 6% perf-sched.wait_time.avg.ms.__cond_resched.truncate_inode_pages_range.evict.do_unlinkat.__x64_sys_unlinkat
0.17 ± 3% +20.3% 0.20 ± 6% perf-sched.wait_time.avg.ms.__cond_resched.unmap_vmas.vms_clear_ptes.part.0
0.58 +16.7% 0.68 perf-sched.wait_time.avg.ms.anon_pipe_read.vfs_read.ksys_read.do_syscall_64
0.21 +21.0% 0.25 ± 2% perf-sched.wait_time.avg.ms.d_alloc_parallel.__lookup_slow.walk_component.link_path_walk
0.02 ± 2% +191.4% 0.05 perf-sched.wait_time.avg.ms.do_task_dead.do_exit.do_group_exit.__x64_sys_exit_group.x64_sys_call
5.93 +11.0% 6.59 perf-sched.wait_time.avg.ms.do_wait.kernel_wait4.do_syscall_64.entry_SYSCALL_64_after_hwframe
0.03 ± 24% +58.0% 0.05 ± 17% perf-sched.wait_time.avg.ms.io_schedule.folio_wait_bit_common.__do_fault.do_read_fault
0.10 +41.0% 0.14 perf-sched.wait_time.avg.ms.io_schedule.folio_wait_bit_common.filemap_fault.__do_fault
0.20 ± 6% +21.9% 0.24 ± 7% perf-sched.wait_time.avg.ms.irqentry_exit_to_user_mode.asm_exc_page_fault.[unknown].[unknown]
0.34 ± 14% +23.2% 0.41 ± 10% perf-sched.wait_time.avg.ms.irqentry_exit_to_user_mode.asm_sysvec_apic_timer_interrupt.[unknown].[unknown]
19.93 ± 4% +12.3% 22.38 perf-sched.wait_time.avg.ms.schedule_hrtimeout_range_clock.poll_schedule_timeout.constprop.0.do_poll
0.21 +28.2% 0.27 perf-sched.wait_time.avg.ms.schedule_preempt_disabled.rwsem_down_read_slowpath.down_read.open_last_lookups
0.20 +23.3% 0.25 perf-sched.wait_time.avg.ms.schedule_preempt_disabled.rwsem_down_read_slowpath.down_read.walk_component
0.20 +20.5% 0.24 perf-sched.wait_time.avg.ms.schedule_preempt_disabled.rwsem_down_write_slowpath.down_write.do_unlinkat
0.49 ± 11% +90.1% 0.92 ± 22% perf-sched.wait_time.avg.ms.schedule_preempt_disabled.rwsem_down_write_slowpath.down_write.dup_mmap
0.13 +26.6% 0.16 perf-sched.wait_time.avg.ms.schedule_preempt_disabled.rwsem_down_write_slowpath.down_write.open_last_lookups
0.02 ± 7% -18.2% 0.01 ± 11% perf-sched.wait_time.avg.ms.schedule_timeout.__wait_for_common.stop_one_cpu.sched_exec
0.53 ± 2% +28.5% 0.68 perf-sched.wait_time.avg.ms.schedule_timeout.__wait_for_common.wait_for_completion_state.kernel_clone
0.20 ± 3% +21.7% 0.25 ± 3% perf-sched.wait_time.avg.ms.sigsuspend.__x64_sys_rt_sigsuspend.do_syscall_64.entry_SYSCALL_64_after_hwframe
7.31 +13.4% 8.29 perf-sched.wait_time.avg.ms.smpboot_thread_fn.kthread.ret_from_fork.ret_from_fork_asm
21.31 ± 55% +61.9% 34.52 ± 7% perf-sched.wait_time.max.ms.__cond_resched.__alloc_frozen_pages_noprof.alloc_pages_mpol.alloc_pages_noprof.pgd_alloc
0.49 ± 33% +124.6% 1.11 ± 42% perf-sched.wait_time.max.ms.__cond_resched.__anon_vma_prepare.__vmf_anon_prepare.do_anonymous_page.__handle_mm_fault
0.39 ± 5% +194.0% 1.15 ± 31% perf-sched.wait_time.max.ms.__cond_resched.__anon_vma_prepare.__vmf_anon_prepare.do_pte_missing.__handle_mm_fault
0.49 ± 14% +104.7% 1.00 ± 39% perf-sched.wait_time.max.ms.__cond_resched.__dentry_kill.dput.step_into.link_path_walk
0.65 ± 50% +126.5% 1.47 ± 31% perf-sched.wait_time.max.ms.__cond_resched.__tlb_batch_free_encoded_pages.tlb_finish_mmu.vms_clear_ptes.part
0.68 ± 22% +98.3% 1.36 ± 32% perf-sched.wait_time.max.ms.__cond_resched.change_pud_range.isra.0.change_protection_range
34.34 ± 5% +14.7% 39.40 ± 3% perf-sched.wait_time.max.ms.__cond_resched.copy_pte_range.copy_p4d_range.copy_page_range.dup_mmap
0.57 ± 12% +95.3% 1.11 ± 16% perf-sched.wait_time.max.ms.__cond_resched.copy_strings.isra.0.do_execveat_common
0.42 ± 20% +112.7% 0.89 ± 25% perf-sched.wait_time.max.ms.__cond_resched.down_read.open_last_lookups.path_openat.do_filp_open
0.74 ± 17% +136.4% 1.76 ± 27% perf-sched.wait_time.max.ms.__cond_resched.down_read.walk_component.link_path_walk.path_lookupat
30.86 +10.2% 34.02 ± 3% perf-sched.wait_time.max.ms.__cond_resched.down_write.unlink_anon_vmas.free_pgtables.exit_mmap
0.30 ± 16% +144.0% 0.72 ± 43% perf-sched.wait_time.max.ms.__cond_resched.down_write.unlink_file_vma_batch_process.free_pgtables.vms_clear_ptes
0.66 ± 39% +116.2% 1.42 ± 44% perf-sched.wait_time.max.ms.__cond_resched.down_write.vma_prepare.__split_vma.vma_modify
0.38 ± 20% +165.9% 1.01 ± 44% perf-sched.wait_time.max.ms.__cond_resched.down_write_killable.vm_mmap_pgoff.elf_load.load_elf_interp
1.03 ± 36% +68.8% 1.75 ± 17% perf-sched.wait_time.max.ms.__cond_resched.dput.d_alloc_parallel.__lookup_slow.walk_component
0.81 ± 13% +94.0% 1.56 ± 13% perf-sched.wait_time.max.ms.__cond_resched.dput.open_last_lookups.path_openat.do_filp_open
0.73 ± 23% +99.7% 1.46 ± 8% perf-sched.wait_time.max.ms.__cond_resched.dput.step_into.link_path_walk.path_lookupat
0.47 ± 30% +116.2% 1.02 ± 30% perf-sched.wait_time.max.ms.__cond_resched.dput.step_into.open_last_lookups.path_openat
28.29 ± 4% +14.2% 32.30 ± 3% perf-sched.wait_time.max.ms.__cond_resched.exit_mmap.__mmput.exit_mm.do_exit
0.40 ± 10% +120.5% 0.88 ± 36% perf-sched.wait_time.max.ms.__cond_resched.filemap_read.__kernel_read.exec_binprm.bprm_execve
0.34 ± 33% +235.3% 1.15 ± 45% perf-sched.wait_time.max.ms.__cond_resched.folio_zero_user.vma_alloc_anon_folio_pmd.__do_huge_pmd_anonymous_page.__handle_mm_fault
0.84 ± 28% +62.4% 1.36 ± 26% perf-sched.wait_time.max.ms.__cond_resched.kmem_cache_alloc_noprof.alloc_empty_file.path_openat.do_filp_open
22.53 ± 49% +59.1% 35.84 ± 6% perf-sched.wait_time.max.ms.__cond_resched.kmem_cache_alloc_noprof.dup_fd.copy_process.kernel_clone
0.41 ± 32% +143.3% 1.00 ± 31% perf-sched.wait_time.max.ms.__cond_resched.kmem_cache_alloc_noprof.mas_alloc_nodes.mas_preallocate.__mmap_new_vma
0.68 ± 19% +54.1% 1.05 ± 18% perf-sched.wait_time.max.ms.__cond_resched.kmem_cache_alloc_noprof.mas_alloc_nodes.mas_preallocate.commit_merge
1.07 ± 22% +62.2% 1.74 ± 29% perf-sched.wait_time.max.ms.__cond_resched.kmem_cache_alloc_noprof.vm_area_alloc.__mmap_new_vma.__mmap_region
0.28 ± 34% +115.8% 0.61 ± 45% perf-sched.wait_time.max.ms.__cond_resched.kmem_cache_alloc_noprof.vm_area_alloc.do_brk_flags.__do_sys_brk
0.30 ± 16% +47.3% 0.45 ± 19% perf-sched.wait_time.max.ms.__cond_resched.mnt_want_write.do_unlinkat.__x64_sys_unlinkat.do_syscall_64
0.39 ± 11% +224.5% 1.27 ± 47% perf-sched.wait_time.max.ms.__cond_resched.remove_vma.vms_complete_munmap_vmas.__mmap_region.do_mmap
1.62 ± 21% +48.0% 2.39 ± 11% perf-sched.wait_time.max.ms.__cond_resched.stop_one_cpu.sched_exec.bprm_execve.part
0.77 ± 8% +108.5% 1.60 ± 17% perf-sched.wait_time.max.ms.__cond_resched.truncate_inode_pages_range.evict.do_unlinkat.__x64_sys_unlinkat
1.12 ± 36% +66.4% 1.86 ± 19% perf-sched.wait_time.max.ms.__cond_resched.unmap_vmas.vms_clear_ptes.part.0
29.76 ± 8% +14.5% 34.08 ± 6% perf-sched.wait_time.max.ms.__cond_resched.uprobe_start_dup_mmap.dup_mm.constprop.0
26.81 ± 9% +18.7% 31.82 ± 5% perf-sched.wait_time.max.ms.__cond_resched.zap_pmd_range.isra.0.unmap_page_range
30.95 ± 2% +14.1% 35.32 ± 3% perf-sched.wait_time.max.ms.__cond_resched.zap_pte_range.zap_pmd_range.isra.0
0.74 ± 23% +101.0% 1.49 ± 12% perf-sched.wait_time.max.ms.d_alloc_parallel.__lookup_slow.walk_component.link_path_walk
4.42 ± 19% +393.4% 21.82 ± 11% perf-sched.wait_time.max.ms.do_task_dead.do_exit.do_group_exit.__x64_sys_exit_group.x64_sys_call
29.59 ± 3% +13.2% 33.51 ± 4% perf-sched.wait_time.max.ms.irqentry_exit_to_user_mode.asm_sysvec_apic_timer_interrupt.[unknown].[unknown]
0.49 ± 43% -45.9% 0.27 ± 57% perf-sched.wait_time.max.ms.irqentry_exit_to_user_mode.asm_sysvec_call_function_single.[unknown].[unknown]
33.37 ± 4% +18.7% 39.60 ± 7% perf-sched.wait_time.max.ms.schedule_preempt_disabled.rwsem_down_write_slowpath.down_write.dup_mmap
0.05 ± 28% -34.7% 0.03 ± 27% perf-sched.wait_time.max.ms.schedule_timeout.__wait_for_common.stop_one_cpu.sched_exec
28.26 ± 4% +22.9% 34.73 ± 3% perf-sched.wait_time.max.ms.sigsuspend.__x64_sys_rt_sigsuspend.do_syscall_64.entry_SYSCALL_64_after_hwframe
***************************************************************************************************
lkp-icl-2sp9: 64 threads 2 sockets Intel(R) Xeon(R) Gold 6346 CPU @ 3.10GHz (Ice Lake) with 256G memory
=========================================================================================
compiler/cpufreq_governor/kconfig/nr_task/rootfs/runtime/tbox_group/test/testcase:
gcc-12/performance/x86_64-rhel-9.4/100%/debian-12-x86_64-20240206.cgz/300s/lkp-icl-2sp9/shell16/unixbench
commit:
5bc34be478 ("sched/core: Reorganize cgroup bandwidth control interface file writes")
ac34cb39e8 ("sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails")
5bc34be478d09c4d ac34cb39e8aea9915ec2f4e08c9
---------------- ---------------------------
%stddev %change %stddev
\ | \
2730104 -10.6% 2439597 meminfo.Shmem
16614 +45.5% 24179 uptime.idle
1.463e+10 +51.2% 2.213e+10 cpuidle..time
1.678e+08 ± 3% -21.0% 1.325e+08 ± 2% cpuidle..usage
3594064 ± 35% -41.5% 2101847 ± 76% numa-meminfo.node0.FilePages
1177451 ± 12% -21.5% 924840 ± 11% numa-meminfo.node0.Shmem
5.265e+08 -20.5% 4.187e+08 numa-numastat.node0.local_node
5.265e+08 -20.5% 4.187e+08 numa-numastat.node0.numa_hit
5.234e+08 -20.4% 4.167e+08 numa-numastat.node1.local_node
5.235e+08 -20.4% 4.168e+08 numa-numastat.node1.numa_hit
36.44 +50.4% 54.81 vmstat.cpu.id
53.69 ± 3% +15.4% 61.93 ± 3% vmstat.procs.r
611600 ± 2% -36.8% 386273 vmstat.system.cs
494859 ± 2% -37.8% 307602 vmstat.system.in
9369 -15.3% 7939 perf-c2c.DRAM.local
29442 -33.9% 19455 perf-c2c.DRAM.remote
22092 -34.9% 14380 perf-c2c.HITM.local
15664 -34.4% 10278 perf-c2c.HITM.remote
37756 -34.7% 24658 perf-c2c.HITM.total
898526 ± 35% -41.5% 525463 ± 76% numa-vmstat.node0.nr_file_pages
294369 ± 12% -21.5% 231222 ± 11% numa-vmstat.node0.nr_shmem
5.265e+08 -20.5% 4.187e+08 numa-vmstat.node0.numa_hit
5.265e+08 -20.5% 4.187e+08 numa-vmstat.node0.numa_local
5.235e+08 -20.4% 4.168e+08 numa-vmstat.node1.numa_hit
5.234e+08 -20.4% 4.167e+08 numa-vmstat.node1.numa_local
36.28 +18.4 54.67 mpstat.cpu.all.idle%
0.00 ± 19% +0.0 0.01 ± 4% mpstat.cpu.all.iowait%
1.24 ± 2% -0.4 0.80 mpstat.cpu.all.irq%
0.65 -0.2 0.49 mpstat.cpu.all.soft%
52.22 -15.0 37.26 ± 2% mpstat.cpu.all.sys%
9.62 -2.8 6.77 mpstat.cpu.all.usr%
70.32 -25.8% 52.19 mpstat.max_utilization_pct
10028 -20.3% 7993 unixbench.throughput
12013870 -17.7% 9885824 ± 2% unixbench.time.involuntary_context_switches
620003 -21.1% 489302 ± 2% unixbench.time.major_page_faults
1.242e+09 -20.4% 9.891e+08 unixbench.time.minor_page_faults
3788 -25.9% 2806 unixbench.time.percent_of_cpu_this_job_got
18741 -26.6% 13750 ± 2% unixbench.time.system_time
5225 -23.2% 4014 unixbench.time.user_time
2.227e+08 -42.0% 1.292e+08 unixbench.time.voluntary_context_switches
6341093 -20.2% 5058834 unixbench.workload
902694 -8.2% 828505 proc-vmstat.nr_active_anon
1593764 -4.6% 1520712 proc-vmstat.nr_file_pages
49655 -3.6% 47878 proc-vmstat.nr_kernel_stack
31705 ± 2% -8.6% 28967 proc-vmstat.nr_mapped
36671 -5.2% 34746 proc-vmstat.nr_page_table_pages
682470 -10.6% 609854 proc-vmstat.nr_shmem
28442 -1.2% 28094 proc-vmstat.nr_slab_reclaimable
57057 -3.2% 55224 proc-vmstat.nr_slab_unreclaimable
902694 -8.2% 828505 proc-vmstat.nr_zone_active_anon
12021 ± 90% +166.4% 32030 ± 23% proc-vmstat.numa_hint_faults_local
1.05e+09 -20.4% 8.355e+08 proc-vmstat.numa_hit
1.05e+09 -20.4% 8.354e+08 proc-vmstat.numa_local
68540 -1.2% 67690 proc-vmstat.numa_other
1.09e+09 -20.8% 8.639e+08 proc-vmstat.pgalloc_normal
1.252e+09 -20.2% 9.994e+08 proc-vmstat.pgfault
1.089e+09 -20.8% 8.631e+08 proc-vmstat.pgfree
62037106 -20.4% 49362493 proc-vmstat.pgreuse
53371 -20.2% 42580 proc-vmstat.thp_fault_alloc
22516441 -20.5% 17901785 proc-vmstat.unevictable_pgs_culled
3.59 -17.9% 2.95 perf-stat.i.MPKI
1.623e+10 -24.9% 1.219e+10 perf-stat.i.branch-instructions
1.57 -0.2 1.40 perf-stat.i.branch-miss-rate%
2.498e+08 -33.0% 1.673e+08 perf-stat.i.branch-misses
2.892e+08 -38.7% 1.774e+08 perf-stat.i.cache-misses
1.186e+09 -39.0% 7.234e+08 perf-stat.i.cache-references
613708 ± 2% -36.8% 387765 perf-stat.i.context-switches
1.90 -4.6% 1.81 perf-stat.i.cpi
1.523e+11 -28.3% 1.091e+11 perf-stat.i.cpu-cycles
222994 -63.6% 81240 ± 2% perf-stat.i.cpu-migrations
535.59 +15.9% 620.57 perf-stat.i.cycles-between-cache-misses
7.918e+10 -24.8% 5.951e+10 perf-stat.i.instructions
0.54 +4.6% 0.56 perf-stat.i.ipc
985.60 -21.0% 778.65 ± 2% perf-stat.i.major-faults
73.54 -24.5% 55.54 perf-stat.i.metric.K/sec
1935828 -20.3% 1543350 perf-stat.i.minor-faults
1936814 -20.3% 1544128 perf-stat.i.page-faults
3.65 -18.4% 2.98 perf-stat.overall.MPKI
1.54 -0.2 1.37 perf-stat.overall.branch-miss-rate%
1.92 -4.7% 1.83 perf-stat.overall.cpi
526.44 +16.8% 614.96 perf-stat.overall.cycles-between-cache-misses
0.52 +4.9% 0.55 perf-stat.overall.ipc
7901309 -5.7% 7454189 perf-stat.overall.path-length
1.62e+10 -24.9% 1.217e+10 perf-stat.ps.branch-instructions
2.494e+08 -33.0% 1.67e+08 perf-stat.ps.branch-misses
2.888e+08 -38.7% 1.771e+08 perf-stat.ps.cache-misses
1.185e+09 -39.0% 7.223e+08 perf-stat.ps.cache-references
612790 ± 2% -36.8% 387169 perf-stat.ps.context-switches
1.52e+11 -28.3% 1.089e+11 perf-stat.ps.cpu-cycles
222664 -63.6% 81128 ± 2% perf-stat.ps.cpu-migrations
7.906e+10 -24.8% 5.942e+10 perf-stat.ps.instructions
984.18 -21.0% 777.37 ± 2% perf-stat.ps.major-faults
1932667 -20.3% 1540796 perf-stat.ps.minor-faults
1933651 -20.3% 1541574 perf-stat.ps.page-faults
5.01e+13 -24.7% 3.771e+13 perf-stat.total.instructions
13122731 -28.7% 9355433 sched_debug.cfs_rq:/.avg_vruntime.avg
15409189 ± 2% -25.8% 11433341 sched_debug.cfs_rq:/.avg_vruntime.max
12592550 -29.2% 8913985 sched_debug.cfs_rq:/.avg_vruntime.min
5.14 ± 16% +54.0% 7.91 ± 15% sched_debug.cfs_rq:/.h_nr_queued.max
0.94 ± 9% +56.5% 1.46 ± 11% sched_debug.cfs_rq:/.h_nr_queued.stddev
4.58 ± 17% +64.2% 7.52 ± 17% sched_debug.cfs_rq:/.h_nr_runnable.max
0.83 ± 8% +62.3% 1.35 ± 12% sched_debug.cfs_rq:/.h_nr_runnable.stddev
21218 ± 18% -35.7% 13650 ± 10% sched_debug.cfs_rq:/.load.avg
627984 ± 25% -42.7% 359859 ± 13% sched_debug.cfs_rq:/.load.max
16.98 ± 2% -18.1% 13.91 ± 3% sched_debug.cfs_rq:/.load_avg.min
13122731 -28.7% 9355433 sched_debug.cfs_rq:/.min_vruntime.avg
15409189 ± 2% -25.8% 11433341 sched_debug.cfs_rq:/.min_vruntime.max
12592550 -29.2% 8913985 sched_debug.cfs_rq:/.min_vruntime.min
0.60 ± 2% -26.9% 0.44 ± 6% sched_debug.cfs_rq:/.nr_queued.avg
879.57 +13.7% 999.66 ± 2% sched_debug.cfs_rq:/.runnable_avg.avg
1573 ± 2% +35.8% 2136 ± 8% sched_debug.cfs_rq:/.runnable_avg.max
255.02 ± 3% +18.1% 301.21 ± 5% sched_debug.cfs_rq:/.runnable_avg.stddev
243.04 ± 3% -14.0% 209.05 sched_debug.cfs_rq:/.util_avg.stddev
29.82 ± 7% +32.6% 39.52 ± 13% sched_debug.cfs_rq:/.util_est.avg
262.67 ± 8% +72.5% 452.98 ± 16% sched_debug.cfs_rq:/.util_est.max
51.96 ± 7% +61.0% 83.65 ± 11% sched_debug.cfs_rq:/.util_est.stddev
170679 ± 2% +88.6% 321939 ± 2% sched_debug.cpu.avg_idle.avg
375875 ± 5% +110.8% 792298 ± 3% sched_debug.cpu.avg_idle.max
27824 ± 14% +111.3% 58800 ± 5% sched_debug.cpu.avg_idle.min
70934 ± 5% +115.4% 152820 ± 2% sched_debug.cpu.avg_idle.stddev
1225277 ± 2% -34.5% 802812 ± 9% sched_debug.cpu.curr->pid.avg
500271 +171.7% 1359127 sched_debug.cpu.max_idle_balance_cost.avg
513437 +190.7% 1492784 sched_debug.cpu.max_idle_balance_cost.max
1752 ± 41% +7584.0% 134642 ± 47% sched_debug.cpu.max_idle_balance_cost.stddev
5.64 ± 14% +49.5% 8.42 ± 19% sched_debug.cpu.nr_running.max
0.99 ± 9% +53.5% 1.53 ± 13% sched_debug.cpu.nr_running.stddev
2889232 ± 2% -36.7% 1829756 sched_debug.cpu.nr_switches.avg
2943872 ± 2% -36.8% 1859463 sched_debug.cpu.nr_switches.max
2793423 ± 2% -36.2% 1781992 sched_debug.cpu.nr_switches.min
28235 ± 7% -51.8% 13616 ± 6% sched_debug.cpu.nr_switches.stddev
50800 ± 18% -88.4% 5891 ± 15% sched_debug.cpu.nr_uninterruptible.max
-96771 -93.5% -6330 sched_debug.cpu.nr_uninterruptible.min
32796 ± 12% -92.2% 2565 ± 12% sched_debug.cpu.nr_uninterruptible.stddev
0.01 ± 14% +211.1% 0.02 ± 23% perf-sched.sch_delay.avg.ms.__cond_resched.__alloc_frozen_pages_noprof.alloc_pages_mpol.vma_alloc_folio_noprof.alloc_anon_folio
0.01 ± 9% +47.3% 0.01 ± 11% perf-sched.sch_delay.avg.ms.__cond_resched.__kmalloc_cache_noprof.perf_event_mmap_event.perf_event_mmap.__mmap_region
0.01 ± 23% +104.8% 0.02 ± 33% perf-sched.sch_delay.avg.ms.__cond_resched.__put_anon_vma.unlink_anon_vmas.free_pgtables.exit_mmap
0.01 ± 13% +71.2% 0.02 ± 13% perf-sched.sch_delay.avg.ms.__cond_resched.do_close_on_exec.begin_new_exec.load_elf_binary.exec_binprm
0.01 ± 9% +67.4% 0.01 ± 20% perf-sched.sch_delay.avg.ms.__cond_resched.down_read.walk_component.link_path_walk.path_openat
0.01 ± 4% +588.7% 0.06 ±166% perf-sched.sch_delay.avg.ms.__cond_resched.down_write.unlink_anon_vmas.free_pgtables.exit_mmap
0.01 ± 14% +107.7% 0.01 ± 28% perf-sched.sch_delay.avg.ms.__cond_resched.down_write.vma_prepare.__split_vma.vma_modify
0.01 ± 21% +64.1% 0.02 ± 22% perf-sched.sch_delay.avg.ms.__cond_resched.down_write_killable.setup_arg_pages.load_elf_binary.exec_binprm
0.01 ± 19% +91.8% 0.02 ± 16% perf-sched.sch_delay.avg.ms.__cond_resched.down_write_killable.vm_mmap_pgoff.elf_load.load_elf_interp
0.01 ± 57% -61.3% 0.00 ± 22% perf-sched.sch_delay.avg.ms.__cond_resched.dput.simple_unlink.vfs_unlink.do_unlinkat
0.01 ± 6% +56.8% 0.01 ± 13% perf-sched.sch_delay.avg.ms.__cond_resched.dput.step_into.link_path_walk.path_openat
0.01 ± 10% +124.4% 0.02 ± 42% perf-sched.sch_delay.avg.ms.__cond_resched.kmem_cache_alloc_noprof.getname_flags.part.0
0.01 ± 16% +82.2% 0.01 ± 20% perf-sched.sch_delay.avg.ms.__cond_resched.kmem_cache_alloc_noprof.vm_area_alloc.__mmap_new_vma.__mmap_region
0.01 ± 4% +32.7% 0.01 ± 8% perf-sched.sch_delay.avg.ms.__cond_resched.smpboot_thread_fn.kthread.ret_from_fork.ret_from_fork_asm
0.01 ± 8% +84.0% 0.02 ± 3% perf-sched.sch_delay.avg.ms.__cond_resched.stop_one_cpu.sched_exec.bprm_execve.part
0.01 ± 5% +50.0% 0.01 ± 15% perf-sched.sch_delay.avg.ms.__cond_resched.unmap_vmas.vms_clear_ptes.part.0
0.01 ± 26% +155.8% 0.02 ± 18% perf-sched.sch_delay.avg.ms.io_schedule.folio_wait_bit_common.__do_fault.do_read_fault
0.01 ± 8% +108.8% 0.03 ± 34% perf-sched.sch_delay.avg.ms.io_schedule.folio_wait_bit_common.filemap_fault.__do_fault
0.01 ± 7% +84.2% 0.01 ± 10% perf-sched.sch_delay.avg.ms.irqentry_exit_to_user_mode.asm_exc_page_fault.[unknown]
0.01 ± 22% +381.2% 0.04 ± 90% perf-sched.sch_delay.avg.ms.irqentry_exit_to_user_mode.asm_sysvec_apic_timer_interrupt.[unknown]
0.01 +109.5% 0.01 ± 10% perf-sched.sch_delay.avg.ms.irqentry_exit_to_user_mode.asm_sysvec_apic_timer_interrupt.[unknown].[unknown]
0.01 ± 21% +38.2% 0.01 ± 20% perf-sched.sch_delay.avg.ms.irqentry_exit_to_user_mode.asm_sysvec_reschedule_ipi.[unknown].[unknown]
0.02 ± 18% +38.5% 0.03 ± 5% perf-sched.sch_delay.avg.ms.schedule_preempt_disabled.rwsem_down_read_slowpath.down_read.open_last_lookups
0.00 ± 21% +78.9% 0.01 ± 26% perf-sched.sch_delay.avg.ms.schedule_preempt_disabled.rwsem_down_write_slowpath.down_write.__mmap_new_vma
0.01 ± 18% +65.1% 0.02 ± 17% perf-sched.sch_delay.avg.ms.schedule_preempt_disabled.rwsem_down_write_slowpath.down_write.open_last_lookups
0.01 ± 4% -12.9% 0.01 perf-sched.sch_delay.avg.ms.smpboot_thread_fn.kthread.ret_from_fork.ret_from_fork_asm
0.03 ± 3% -19.5% 0.03 ± 2% perf-sched.sch_delay.avg.ms.worker_thread.kthread.ret_from_fork.ret_from_fork_asm
0.14 ± 36% +69.3% 0.24 ± 34% perf-sched.sch_delay.max.ms.__cond_resched.__alloc_frozen_pages_noprof.alloc_pages_mpol.alloc_pages_noprof.__pmd_alloc
0.14 ± 68% +754.0% 1.18 ± 34% perf-sched.sch_delay.max.ms.__cond_resched.__alloc_frozen_pages_noprof.alloc_pages_mpol.vma_alloc_folio_noprof.alloc_anon_folio
0.17 ± 46% +350.2% 0.76 ± 51% perf-sched.sch_delay.max.ms.__cond_resched.__alloc_frozen_pages_noprof.alloc_pages_mpol.vma_alloc_folio_noprof.wp_page_copy
0.16 ± 31% +176.8% 0.46 ± 47% perf-sched.sch_delay.max.ms.__cond_resched.__kmalloc_cache_noprof.perf_event_mmap_event.perf_event_mmap.__mmap_region
0.09 ± 37% +296.4% 0.37 ± 46% perf-sched.sch_delay.max.ms.__cond_resched.__put_anon_vma.unlink_anon_vmas.free_pgtables.exit_mmap
0.06 ± 32% +811.7% 0.56 ± 57% perf-sched.sch_delay.max.ms.__cond_resched.change_pud_range.isra.0.change_protection_range
0.07 ± 24% +137.0% 0.16 ± 32% perf-sched.sch_delay.max.ms.__cond_resched.do_close_on_exec.begin_new_exec.load_elf_binary.exec_binprm
0.13 ± 59% +817.1% 1.24 ± 56% perf-sched.sch_delay.max.ms.__cond_resched.down_read.walk_component.link_path_walk.path_openat
0.13 ± 13% +9995.6% 12.72 ±212% perf-sched.sch_delay.max.ms.__cond_resched.down_write.unlink_anon_vmas.free_pgtables.exit_mmap
0.07 ± 40% +669.3% 0.50 ± 49% perf-sched.sch_delay.max.ms.__cond_resched.down_write.vma_prepare.__split_vma.vma_modify
0.07 ± 67% +176.5% 0.21 ± 35% perf-sched.sch_delay.max.ms.__cond_resched.down_write_killable.map_vdso.load_elf_binary.exec_binprm
0.10 ± 26% +125.2% 0.23 ± 26% perf-sched.sch_delay.max.ms.__cond_resched.down_write_killable.vm_mmap_pgoff.elf_load.load_elf_interp
0.18 ± 41% +4953.1% 8.97 ±146% perf-sched.sch_delay.max.ms.__cond_resched.dput.open_last_lookups.path_openat.do_filp_open
0.23 ± 52% +333.0% 0.99 ± 41% perf-sched.sch_delay.max.ms.__cond_resched.dput.step_into.link_path_walk.path_openat
0.10 ± 25% +108.5% 0.22 ± 30% perf-sched.sch_delay.max.ms.__cond_resched.exit_mmap.__mmput.exec_mmap.begin_new_exec
0.06 ± 53% +914.3% 0.58 ± 47% perf-sched.sch_delay.max.ms.__cond_resched.kmem_cache_alloc_noprof.getname_flags.part.0
0.04 ± 30% +476.7% 0.24 ±129% perf-sched.sch_delay.max.ms.__cond_resched.kmem_cache_alloc_noprof.mas_alloc_nodes.mas_preallocate.commit_merge
0.07 ± 49% +182.2% 0.18 ± 41% perf-sched.sch_delay.max.ms.__cond_resched.kmem_cache_alloc_noprof.mas_alloc_nodes.mas_preallocate.vma_shrink
0.10 ± 37% +480.3% 0.57 ± 49% perf-sched.sch_delay.max.ms.__cond_resched.kmem_cache_alloc_noprof.vm_area_alloc.__mmap_new_vma.__mmap_region
0.09 ± 53% +130.5% 0.20 ± 21% perf-sched.sch_delay.max.ms.__cond_resched.kmem_cache_alloc_noprof.vm_area_alloc._install_special_mapping.map_vdso
0.18 ± 38% +189.6% 0.52 ± 32% perf-sched.sch_delay.max.ms.__cond_resched.unmap_vmas.vms_clear_ptes.part.0
0.07 ± 46% +290.1% 0.28 ± 45% perf-sched.sch_delay.max.ms.__cond_resched.zap_pmd_range.isra.0.unmap_page_range
0.03 ±111% +1015.2% 0.37 ±101% perf-sched.sch_delay.max.ms.d_alloc_parallel.__lookup_slow.walk_component.path_lookupat
0.08 ± 41% +249.3% 0.26 ± 28% perf-sched.sch_delay.max.ms.io_schedule.folio_wait_bit_common.__do_fault.do_read_fault
0.17 ± 42% +346.9% 0.77 ± 27% perf-sched.sch_delay.max.ms.irqentry_exit_to_user_mode.asm_exc_page_fault.[unknown]
0.26 ± 30% +490.9% 1.54 ± 18% perf-sched.sch_delay.max.ms.irqentry_exit_to_user_mode.asm_sysvec_apic_timer_interrupt.[unknown].[unknown]
0.08 ± 48% +638.6% 0.61 ± 67% perf-sched.sch_delay.max.ms.irqentry_exit_to_user_mode.asm_sysvec_reschedule_ipi.[unknown]
0.06 ± 74% +523.0% 0.38 ± 64% perf-sched.sch_delay.max.ms.irqentry_exit_to_user_mode.asm_sysvec_reschedule_ipi.[unknown].[unknown]
0.16 ± 55% +289.8% 0.63 ± 82% perf-sched.sch_delay.max.ms.schedule_hrtimeout_range_clock.poll_schedule_timeout.constprop.0.do_poll
0.24 ± 68% +124.3% 0.53 ± 27% perf-sched.sch_delay.max.ms.schedule_preempt_disabled.rwsem_down_write_slowpath.down_write.__mmap_new_vma
1962 ± 9% +52.1% 2986 ± 26% perf-sched.total_wait_and_delay.max.ms
1962 ± 9% +52.1% 2986 ± 26% perf-sched.total_wait_time.max.ms
6.10 ± 3% +16.5% 7.11 ± 3% perf-sched.wait_and_delay.avg.ms.__cond_resched.smpboot_thread_fn.kthread.ret_from_fork.ret_from_fork_asm
0.02 ± 2% +172.7% 0.06 perf-sched.wait_and_delay.avg.ms.do_task_dead.do_exit.do_group_exit.__x64_sys_exit_group.x64_sys_call
2.86 ± 3% +16.5% 3.33 ± 4% perf-sched.wait_and_delay.avg.ms.schedule_preempt_disabled.rwsem_down_write_slowpath.down_write.do_unlinkat
457.67 ± 5% -13.3% 397.00 ± 4% perf-sched.wait_and_delay.count.__cond_resched.__tlb_batch_free_encoded_pages.tlb_finish_mmu.exit_mmap.__mmput
31.00 ± 12% -36.6% 19.67 ± 19% perf-sched.wait_and_delay.count.__cond_resched.pidfs_exit.release_task.wait_task_zombie.__do_wait
2114 ± 5% +18.8% 2512 ± 5% perf-sched.wait_and_delay.count.__cond_resched.smpboot_thread_fn.kthread.ret_from_fork.ret_from_fork_asm
1443 ± 2% -11.9% 1272 ± 2% perf-sched.wait_and_delay.count.irqentry_exit_to_user_mode.asm_sysvec_apic_timer_interrupt.[unknown]
73.43 ± 13% -49.8% 36.86 ± 72% perf-sched.wait_and_delay.max.ms.__cond_resched.kmem_cache_alloc_lru_noprof.__d_alloc.d_alloc_pseudo.alloc_file_pseudo
8.47 ± 9% +34.4% 11.39 ± 8% perf-sched.wait_and_delay.max.ms.__cond_resched.stop_one_cpu.sched_exec.bprm_execve.part
5.00 ± 13% +512.7% 30.62 ± 20% perf-sched.wait_and_delay.max.ms.do_task_dead.do_exit.do_group_exit.__x64_sys_exit_group.x64_sys_call
1962 ± 9% +52.1% 2986 ± 26% perf-sched.wait_and_delay.max.ms.worker_thread.kthread.ret_from_fork.ret_from_fork_asm
0.08 ±207% +356.6% 0.36 ± 70% perf-sched.wait_time.avg.ms.__cond_resched.__do_fault.do_read_fault.do_pte_missing.__handle_mm_fault
3.33 ± 6% +10.2% 3.67 ± 7% perf-sched.wait_time.avg.ms.__cond_resched.change_pud_range.isra.0.change_protection_range
3.90 ± 6% +9.7% 4.27 ± 4% perf-sched.wait_time.avg.ms.__cond_resched.dput.step_into.open_last_lookups.path_openat
6.09 ± 3% +16.5% 7.10 ± 3% perf-sched.wait_time.avg.ms.__cond_resched.smpboot_thread_fn.kthread.ret_from_fork.ret_from_fork_asm
3.12 ± 3% +16.5% 3.63 ± 6% perf-sched.wait_time.avg.ms.__cond_resched.truncate_inode_pages_range.evict.do_unlinkat.__x64_sys_unlinkat
0.02 ± 2% +172.7% 0.06 perf-sched.wait_time.avg.ms.do_task_dead.do_exit.do_group_exit.__x64_sys_exit_group.x64_sys_call
1.47 ± 3% +13.9% 1.67 perf-sched.wait_time.avg.ms.io_schedule.folio_wait_bit_common.filemap_fault.__do_fault
2.94 ± 19% +53.8% 4.52 ± 9% perf-sched.wait_time.avg.ms.irqentry_exit_to_user_mode.asm_sysvec_reschedule_ipi.[unknown].[unknown]
2.84 ± 3% +16.1% 3.30 ± 3% perf-sched.wait_time.avg.ms.schedule_preempt_disabled.rwsem_down_write_slowpath.down_write.do_unlinkat
6.50 ± 5% +25.4% 8.15 ± 7% perf-sched.wait_time.max.ms.__cond_resched.down_read.walk_component.link_path_walk.path_lookupat
6.15 ± 8% +30.1% 8.00 ± 18% perf-sched.wait_time.max.ms.__cond_resched.down_write.__mmap_new_vma.__mmap_region.do_mmap
7.61 ± 6% +106.6% 15.72 ± 87% perf-sched.wait_time.max.ms.__cond_resched.dput.open_last_lookups.path_openat.do_filp_open
5.59 ± 13% +38.8% 7.75 ± 10% perf-sched.wait_time.max.ms.__cond_resched.dput.step_into.open_last_lookups.path_openat
73.42 ± 13% -48.7% 37.66 ± 68% perf-sched.wait_time.max.ms.__cond_resched.kmem_cache_alloc_lru_noprof.__d_alloc.d_alloc_pseudo.alloc_file_pseudo
6.55 ± 5% +14.5% 7.50 ± 7% perf-sched.wait_time.max.ms.__cond_resched.kmem_cache_alloc_noprof.alloc_empty_file.path_openat.do_filp_open
8.46 ± 9% +34.3% 11.36 ± 8% perf-sched.wait_time.max.ms.__cond_resched.stop_one_cpu.sched_exec.bprm_execve.part
5.00 ± 13% +512.7% 30.62 ± 20% perf-sched.wait_time.max.ms.do_task_dead.do_exit.do_group_exit.__x64_sys_exit_group.x64_sys_call
18.28 ±130% +313.9% 75.66 ± 16% perf-sched.wait_time.max.ms.irqentry_exit_to_user_mode.asm_sysvec_reschedule_ipi.[unknown].[unknown]
1962 ± 9% +52.1% 2986 ± 26% perf-sched.wait_time.max.ms.worker_thread.kthread.ret_from_fork.ret_from_fork_asm
***************************************************************************************************
lkp-icl-2sp9: 64 threads 2 sockets Intel(R) Xeon(R) Gold 6346 CPU @ 3.10GHz (Ice Lake) with 256G memory
=========================================================================================
compiler/cpufreq_governor/kconfig/nr_task/rootfs/runtime/tbox_group/test/testcase:
gcc-12/performance/x86_64-rhel-9.4/100%/debian-12-x86_64-20240206.cgz/300s/lkp-icl-2sp9/shell8/unixbench
commit:
5bc34be478 ("sched/core: Reorganize cgroup bandwidth control interface file writes")
ac34cb39e8 ("sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails")
5bc34be478d09c4d ac34cb39e8aea9915ec2f4e08c9
---------------- ---------------------------
%stddev %change %stddev
\ | \
22.83 ± 60% +140.9% 55.00 ± 56% perf-sched.wait_and_delay.count.worker_thread.kthread.ret_from_fork.ret_from_fork_asm
3708 +24.7% 4625 ± 2% uptime.idle
1.461e+09 ± 2% +56.0% 2.279e+09 ± 2% cpuidle..time
19339144 ± 3% -26.4% 14234823 ± 3% cpuidle..usage
36.38 +53.9% 56.00 vmstat.cpu.id
631990 ± 2% -40.3% 377172 ± 2% vmstat.system.cs
507992 ± 2% -40.5% 302370 vmstat.system.in
54790263 -26.6% 40229835 numa-numastat.node0.local_node
54813627 -26.6% 40257329 numa-numastat.node0.numa_hit
54280109 -25.6% 40400612 numa-numastat.node1.local_node
54337234 -25.6% 40440402 numa-numastat.node1.numa_hit
54813360 -26.6% 40257724 numa-vmstat.node0.numa_hit
54789997 -26.6% 40230231 numa-vmstat.node0.numa_local
54337173 -25.6% 40439842 numa-vmstat.node1.numa_hit
54280054 -25.6% 40400056 numa-vmstat.node1.numa_local
34.50 +20.2 54.74 mpstat.cpu.all.idle%
0.00 ± 43% +0.0 0.00 ± 20% mpstat.cpu.all.iowait%
1.30 ± 2% -0.5 0.81 mpstat.cpu.all.irq%
0.62 -0.2 0.46 mpstat.cpu.all.soft%
53.55 -16.2 37.32 ± 2% mpstat.cpu.all.sys%
10.03 -3.4 6.67 mpstat.cpu.all.usr%
72.84 -28.5% 52.04 ± 3% mpstat.max_utilization_pct
24992 -4.7% 23818 proc-vmstat.nr_page_table_pages
50622 -2.0% 49590 proc-vmstat.nr_slab_unreclaimable
1.092e+08 -26.1% 80699262 proc-vmstat.numa_hit
1.091e+08 -26.1% 80631976 proc-vmstat.numa_local
1.13e+08 -26.3% 83331586 proc-vmstat.pgalloc_normal
1.302e+08 -25.8% 96571708 proc-vmstat.pgfault
1.129e+08 -26.3% 83193858 proc-vmstat.pgfree
6371181 -26.1% 4708130 proc-vmstat.pgreuse
5521 ± 2% -25.3% 4122 proc-vmstat.thp_fault_alloc
2323235 -26.1% 1716008 proc-vmstat.unevictable_pgs_culled
34426 -26.2% 25392 unixbench.score
20655 -26.2% 15235 unixbench.throughput
1172933 -26.4% 863436 ± 4% unixbench.time.involuntary_context_switches
68518 -25.7% 50886 ± 2% unixbench.time.major_page_faults
1.295e+08 -26.0% 95855227 unixbench.time.minor_page_faults
3974 -28.2% 2852 ± 2% unixbench.time.percent_of_cpu_this_job_got
1994 -28.5% 1426 ± 3% unixbench.time.system_time
538.91 -29.3% 381.20 unixbench.time.user_time
23209907 -44.1% 12967611 unixbench.time.voluntary_context_switches
1301317 -26.2% 959835 unixbench.workload
3.20 -15.9% 2.69 perf-stat.i.MPKI
1.691e+10 -28.2% 1.214e+10 perf-stat.i.branch-instructions
1.75 -0.1 1.62 ± 2% perf-stat.i.branch-miss-rate%
2.685e+08 -33.5% 1.786e+08 perf-stat.i.branch-misses
23.70 -0.4 23.28 perf-stat.i.cache-miss-rate%
2.751e+08 -39.9% 1.654e+08 perf-stat.i.cache-misses
1.154e+09 -38.8% 7.061e+08 perf-stat.i.cache-references
662789 ± 2% -40.6% 393867 ± 2% perf-stat.i.context-switches
1.86 -2.2% 1.82 perf-stat.i.cpi
1.585e+11 -30.1% 1.108e+11 ± 2% perf-stat.i.cpu-cycles
238322 -63.0% 88291 ± 3% perf-stat.i.cpu-migrations
625.36 +15.2% 720.11 ± 2% perf-stat.i.cycles-between-cache-misses
8.25e+10 -28.2% 5.924e+10 perf-stat.i.instructions
1074 -25.5% 800.25 ± 2% perf-stat.i.major-faults
76.11 -29.7% 53.52 perf-stat.i.metric.K/sec
1989387 -25.8% 1476846 perf-stat.i.minor-faults
1990462 -25.8% 1477646 perf-stat.i.page-faults
479.50 ± 44% +39.7% 669.77 perf-stat.overall.cycles-between-cache-misses
0.43 ± 44% +23.1% 0.53 perf-stat.overall.ipc
0.47 ±154% +1.2 1.65 ± 35% perf-profile.calltrace.cycles-pp.zap_present_ptes.zap_pte_range.zap_pmd_range.unmap_page_range.unmap_vmas
1.20 ± 83% +2.1 3.26 ± 41% perf-profile.calltrace.cycles-pp.handle_mm_fault.do_user_addr_fault.exc_page_fault.asm_exc_page_fault
1.34 ± 80% +2.4 3.72 ± 34% perf-profile.calltrace.cycles-pp.do_user_addr_fault.exc_page_fault.asm_exc_page_fault
1.34 ± 80% +2.6 3.92 ± 27% perf-profile.calltrace.cycles-pp.exc_page_fault.asm_exc_page_fault
1.34 ± 80% +3.1 4.42 ± 33% perf-profile.calltrace.cycles-pp.asm_exc_page_fault
1.20 ± 83% +3.3 4.50 ± 75% perf-profile.calltrace.cycles-pp.__handle_mm_fault.handle_mm_fault.do_user_addr_fault.exc_page_fault.asm_exc_page_fault
0.05 ±223% +0.7 0.74 ± 75% perf-profile.children.cycles-pp.try_to_wake_up
0.40 ± 98% +0.7 1.14 ± 54% perf-profile.children.cycles-pp.elf_load
0.25 ±101% +0.9 1.11 ± 54% perf-profile.children.cycles-pp.next_uptodate_folio
0.00 +0.9 0.88 ± 98% perf-profile.children.cycles-pp.sched_balance_update_blocked_averages
0.04 ±223% +1.0 1.06 ±109% perf-profile.children.cycles-pp.do_anonymous_page
0.37 ± 91% +1.0 1.41 ± 41% perf-profile.children.cycles-pp.wp_page_copy
0.00 +1.1 1.06 ±110% perf-profile.children.cycles-pp.clockevents_program_event
0.28 ±126% +1.2 1.44 ± 39% perf-profile.children.cycles-pp.ktime_get
0.60 ±110% +1.3 1.91 ± 25% perf-profile.children.cycles-pp.zap_present_ptes
0.36 ±116% +1.3 1.67 ± 81% perf-profile.children.cycles-pp.lookup_fast
0.60 ±111% +1.5 2.07 ± 25% perf-profile.children.cycles-pp.walk_component
0.77 ± 88% +2.2 3.01 ± 33% perf-profile.children.cycles-pp.link_path_walk
1.53 ± 74% +4.2 5.74 ± 58% perf-profile.children.cycles-pp.__handle_mm_fault
1.92 ± 74% +4.5 6.46 ± 40% perf-profile.children.cycles-pp.do_user_addr_fault
1.58 ± 74% +4.6 6.13 ± 52% perf-profile.children.cycles-pp.handle_mm_fault
1.92 ± 74% +4.6 6.51 ± 39% perf-profile.children.cycles-pp.exc_page_fault
1.96 ± 75% +5.3 7.22 ± 39% perf-profile.children.cycles-pp.asm_exc_page_fault
0.04 ±223% +0.6 0.69 ± 48% perf-profile.self.cycles-pp.folio_remove_rmap_ptes
0.31 ±141% +0.7 1.02 ± 25% perf-profile.self.cycles-pp.zap_present_ptes
0.12 ±150% +1.2 1.29 ± 45% perf-profile.self.cycles-pp.ktime_get
0.84 ± 98% +1.3 2.10 ± 17% perf-profile.self.cycles-pp._raw_spin_lock
1458020 -31.4% 999894 ± 2% sched_debug.cfs_rq:/.avg_vruntime.avg
1335243 -31.5% 914846 ± 2% sched_debug.cfs_rq:/.avg_vruntime.min
0.61 ± 23% +49.0% 0.91 ± 34% sched_debug.cfs_rq:/.h_nr_queued.stddev
1428441 ± 6% -44.3% 795691 ± 44% sched_debug.cfs_rq:/.left_deadline.max
198879 ± 18% -38.9% 121555 ± 48% sched_debug.cfs_rq:/.left_deadline.stddev
1428352 ± 6% -44.3% 795639 ± 44% sched_debug.cfs_rq:/.left_vruntime.max
198866 ± 18% -38.9% 121547 ± 48% sched_debug.cfs_rq:/.left_vruntime.stddev
1458020 -31.4% 999894 ± 2% sched_debug.cfs_rq:/.min_vruntime.avg
1335243 -31.5% 914846 ± 2% sched_debug.cfs_rq:/.min_vruntime.min
1428352 ± 6% -44.3% 795639 ± 44% sched_debug.cfs_rq:/.right_vruntime.max
198866 ± 18% -38.9% 121547 ± 48% sched_debug.cfs_rq:/.right_vruntime.stddev
142.08 ± 23% +42.8% 202.83 ± 14% sched_debug.cfs_rq:/.runnable_avg.min
147.33 ± 21% +41.8% 208.92 ± 6% sched_debug.cfs_rq:/.util_avg.min
322.73 ± 9% -17.1% 267.44 ± 3% sched_debug.cfs_rq:/.util_avg.stddev
388303 ± 2% +51.7% 589066 ± 4% sched_debug.cpu.avg_idle.avg
661789 ± 11% +152.6% 1672006 ± 3% sched_debug.cpu.avg_idle.max
151173 ± 6% +114.9% 324892 ± 8% sched_debug.cpu.avg_idle.stddev
392290 ± 10% -44.0% 219613 ± 21% sched_debug.cpu.curr->pid.avg
631181 -26.0% 467219 sched_debug.cpu.curr->pid.max
302713 ± 2% -24.8% 227699 ± 2% sched_debug.cpu.curr->pid.stddev
501647 +103.6% 1021336 ± 5% sched_debug.cpu.max_idle_balance_cost.avg
575980 ± 10% +158.5% 1488876 sched_debug.cpu.max_idle_balance_cost.max
10437 ± 76% +3252.4% 349893 ± 5% sched_debug.cpu.max_idle_balance_cost.stddev
310053 ± 2% -40.3% 185018 sched_debug.cpu.nr_switches.avg
336326 -40.1% 201480 ± 4% sched_debug.cpu.nr_switches.max
284218 ± 2% -39.7% 171324 ± 2% sched_debug.cpu.nr_switches.min
11002 ± 8% -58.5% 4569 ± 14% sched_debug.cpu.nr_switches.stddev
28877 ± 23% -97.4% 755.50 ± 20% sched_debug.cpu.nr_uninterruptible.max
-36786 -98.4% -578.42 sched_debug.cpu.nr_uninterruptible.min
17077 ± 10% -98.4% 268.08 ± 10% sched_debug.cpu.nr_uninterruptible.stddev
Disclaimer:
Results have been estimated based on internal Intel analysis and are provided
for informational purposes only. Any difference in system hardware or software
design or configuration may affect actual performance.
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
2025-07-15 7:08 ` [PATCH v2] sched/fair: bump " kernel test robot
@ 2025-07-15 10:08 ` Chen, Yu C
2025-07-15 15:38 ` Chris Mason
2025-07-16 11:25 ` Peter Zijlstra
0 siblings, 2 replies; 11+ messages in thread
From: Chen, Yu C @ 2025-07-15 10:08 UTC (permalink / raw)
To: kernel test robot, Chris Mason
Cc: oe-lkp, lkp, linux-kernel, aubrey.li, peterz, vincent.guittot
On 7/15/2025 3:08 PM, kernel test robot wrote:
>
>
> Hello,
>
> kernel test robot noticed a 22.9% regression of unixbench.throughput on:
>
>
> commit: ac34cb39e8aea9915ec2f4e08c979eb2ed1d7561 ("[PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails")
> url: https://github.com/intel-lab-lkp/linux/commits/Chris-Mason/sched-fair-bump-sd-max_newidle_lb_cost-when-newidle-balance-fails/20250626-224805
> base: https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git 5bc34be478d09c4d16009e665e020ad0fcd0deea
> patch link: https://lore.kernel.org/all/20250626144017.1510594-2-clm@fb.com/
> patch subject: [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
>
> testcase: unixbench
> config: x86_64-rhel-9.4
> compiler: gcc-12
> test machine: 64 threads 2 sockets Intel(R) Xeon(R) Gold 6346 CPU @ 3.10GHz (Ice Lake) with 256G memory
> parameters:
>
> runtime: 300s
> nr_task: 100%
> test: shell1
> cpufreq_governor: performance
>
>
...
>
> commit:
> 5bc34be478 ("sched/core: Reorganize cgroup bandwidth control interface file writes")
> ac34cb39e8 ("sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails")
>
> 5bc34be478d09c4d ac34cb39e8aea9915ec2f4e08c9
> ---------------- ---------------------------
> %stddev %change %stddev
> \ | \
...
> 40.37 +16.9 57.24 mpstat.cpu.all.idle%
This commit inhibits the newidle balance. It seems that some workloads
do not like newlyidle balance, like schbench, which is short duration
task. While other workloads want the newidle balance to pull at its best
effort, like unixbench shell test case.
Just wonder if we can check the sched domain's average utilization to
decide how hard we should trigger the newly idle balance, or can we check
the overutilized flag to decide whether we should launch the
new idle balance, something I was thinking of:
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9e24038fa000..6c7420ed484e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -13759,7 +13759,8 @@ static int sched_balance_newidle(struct rq
*this_rq, struct rq_flags *rf)
sd = rcu_dereference_check_sched_domain(this_rq->sd);
if (!get_rd_overloaded(this_rq->rd) ||
- (sd && this_rq->avg_idle < sd->max_newidle_lb_cost)) {
+ (sd && this_rq->avg_idle < sd->max_newidle_lb_cost &&
+ !READ_ONCE(this_rq->rd->overutilized))) {
if (sd)
update_next_balance(sd, &next_balance);
thanks,
Chenyu
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
2025-07-15 10:08 ` Chen, Yu C
@ 2025-07-15 15:38 ` Chris Mason
2025-07-16 15:56 ` Chen, Yu C
2025-07-16 11:25 ` Peter Zijlstra
1 sibling, 1 reply; 11+ messages in thread
From: Chris Mason @ 2025-07-15 15:38 UTC (permalink / raw)
To: Chen, Yu C, kernel test robot, Chris Mason
Cc: oe-lkp, lkp, linux-kernel, aubrey.li, peterz, vincent.guittot
On 7/15/25 6:08 AM, Chen, Yu C wrote:
> On 7/15/2025 3:08 PM, kernel test robot wrote:
>>
>>
>> Hello,
>>
>> kernel test robot noticed a 22.9% regression of unixbench.throughput on:
>>
>>
>> commit: ac34cb39e8aea9915ec2f4e08c979eb2ed1d7561 ("[PATCH v2] sched/
>> fair: bump sd->max_newidle_lb_cost when newidle balance fails")
>> url: https://github.com/intel-lab-lkp/linux/commits/Chris-Mason/sched-
>> fair-bump-sd-max_newidle_lb_cost-when-newidle-balance-
>> fails/20250626-224805 base: https://git.kernel.org/cgit/linux/kernel/
>> git/tip/tip.git 5bc34be478d09c4d16009e665e020ad0fcd0deea
>> patch link: https://lore.kernel.org/all/20250626144017.1510594-2-
>> clm@fb.com/ patch subject: [PATCH v2] sched/fair: bump sd-
>> >max_newidle_lb_cost when newidle balance fails
[ ... ]
>>
>> commit:
>> 5bc34be478 ("sched/core: Reorganize cgroup bandwidth control
>> interface file writes")
>> ac34cb39e8 ("sched/fair: bump sd->max_newidle_lb_cost when newidle
>> balance fails")
>>
>> 5bc34be478d09c4d ac34cb39e8aea9915ec2f4e08c9
>> ---------------- ---------------------------
>> %stddev %change %stddev
>> \ | \
> ...
>
>> 40.37 +16.9 57.24 mpstat.cpu.all.idle%
>
> This commit inhibits the newidle balance. It seems that some workloads
> do not like newlyidle balance, like schbench, which is short duration
> task. While other workloads want the newidle balance to pull at its best
> effort, like unixbench shell test case.
> Just wonder if we can check the sched domain's average utilization to
> decide how hard we should trigger the newly idle balance, or can we check
> the overutilized flag to decide whether we should launch the
> new idle balance, something I was thinking of:
Thanks for looking at this.
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 9e24038fa000..6c7420ed484e 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -13759,7 +13759,8 @@ static int sched_balance_newidle(struct rq
> *this_rq, struct rq_flags *rf)
> sd = rcu_dereference_check_sched_domain(this_rq->sd);
>
> if (!get_rd_overloaded(this_rq->rd) ||
> - (sd && this_rq->avg_idle < sd->max_newidle_lb_cost)) {
> + (sd && this_rq->avg_idle < sd->max_newidle_lb_cost &&
> + !READ_ONCE(this_rq->rd->overutilized))) {
>
> if (sd)
> update_next_balance(sd, &next_balance);
>
Looking at rd->overutilized, I think we only set it when
sched_energy_enabled(). I'm not sure if that's true often enough to use
as a fix for hackbench?
-chris
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
2025-07-15 15:38 ` Chris Mason
@ 2025-07-16 15:56 ` Chen, Yu C
0 siblings, 0 replies; 11+ messages in thread
From: Chen, Yu C @ 2025-07-16 15:56 UTC (permalink / raw)
To: Chris Mason, Chris Mason
Cc: oe-lkp, lkp, linux-kernel, aubrey.li, peterz, vincent.guittot,
kernel test robot
On 7/15/2025 11:38 PM, Chris Mason wrote:
> On 7/15/25 6:08 AM, Chen, Yu C wrote:
>> On 7/15/2025 3:08 PM, kernel test robot wrote:
>>>
>>>
>>> Hello,
>>>
>>> kernel test robot noticed a 22.9% regression of unixbench.throughput on:
>>>
>>>
>>> commit: ac34cb39e8aea9915ec2f4e08c979eb2ed1d7561 ("[PATCH v2] sched/
>>> fair: bump sd->max_newidle_lb_cost when newidle balance fails")
>>> url: https://github.com/intel-lab-lkp/linux/commits/Chris-Mason/sched-
>>> fair-bump-sd-max_newidle_lb_cost-when-newidle-balance-
>>> fails/20250626-224805 base: https://git.kernel.org/cgit/linux/kernel/
>>> git/tip/tip.git 5bc34be478d09c4d16009e665e020ad0fcd0deea
>>> patch link: https://lore.kernel.org/all/20250626144017.1510594-2-
>>> clm@fb.com/ patch subject: [PATCH v2] sched/fair: bump sd-
>>>> max_newidle_lb_cost when newidle balance fails
>
> [ ... ]
>
>>>
>>> commit:
>>> 5bc34be478 ("sched/core: Reorganize cgroup bandwidth control
>>> interface file writes")
>>> ac34cb39e8 ("sched/fair: bump sd->max_newidle_lb_cost when newidle
>>> balance fails")
>>>
>>> 5bc34be478d09c4d ac34cb39e8aea9915ec2f4e08c9
>>> ---------------- ---------------------------
>>> %stddev %change %stddev
>>> \ | \
>> ...
>>
>>> 40.37 +16.9 57.24 mpstat.cpu.all.idle%
>>
>> This commit inhibits the newidle balance. It seems that some workloads
>> do not like newlyidle balance, like schbench, which is short duration
>> task. While other workloads want the newidle balance to pull at its best
>> effort, like unixbench shell test case.
>> Just wonder if we can check the sched domain's average utilization to
>> decide how hard we should trigger the newly idle balance, or can we check
>> the overutilized flag to decide whether we should launch the
>> new idle balance, something I was thinking of:
>
> Thanks for looking at this.
>
>>
>> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
>> index 9e24038fa000..6c7420ed484e 100644
>> --- a/kernel/sched/fair.c
>> +++ b/kernel/sched/fair.c
>> @@ -13759,7 +13759,8 @@ static int sched_balance_newidle(struct rq
>> *this_rq, struct rq_flags *rf)
>> sd = rcu_dereference_check_sched_domain(this_rq->sd);
>>
>> if (!get_rd_overloaded(this_rq->rd) ||
>> - (sd && this_rq->avg_idle < sd->max_newidle_lb_cost)) {
>> + (sd && this_rq->avg_idle < sd->max_newidle_lb_cost &&
>> + !READ_ONCE(this_rq->rd->overutilized))) {
>>
>> if (sd)
>> update_next_balance(sd, &next_balance);
>>
>
>
> Looking at rd->overutilized, I think we only set it when
> sched_energy_enabled(). I'm not sure if that's true often enough to use
> as a fix for hackbench?
>
OK, overutilized is only used for EAS.
I just had a try but can not reproduce this issue on a 240 CPUs system
using unixbench:
./Run shell1 -i 30 -c 240
will need to double check with lkp/0day to figure out.
thanks,
Chenyu
> -chris
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
2025-07-15 10:08 ` Chen, Yu C
2025-07-15 15:38 ` Chris Mason
@ 2025-07-16 11:25 ` Peter Zijlstra
2025-07-16 15:58 ` Chen, Yu C
1 sibling, 1 reply; 11+ messages in thread
From: Peter Zijlstra @ 2025-07-16 11:25 UTC (permalink / raw)
To: Chen, Yu C
Cc: kernel test robot, Chris Mason, oe-lkp, lkp, linux-kernel,
aubrey.li, vincent.guittot
On Tue, Jul 15, 2025 at 06:08:43PM +0800, Chen, Yu C wrote:
> On 7/15/2025 3:08 PM, kernel test robot wrote:
> >
> >
> > Hello,
> >
> > kernel test robot noticed a 22.9% regression of unixbench.throughput on:
> >
> >
> > commit: ac34cb39e8aea9915ec2f4e08c979eb2ed1d7561 ("[PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails")
> > url: https://github.com/intel-lab-lkp/linux/commits/Chris-Mason/sched-fair-bump-sd-max_newidle_lb_cost-when-newidle-balance-fails/20250626-224805
> > base: https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git 5bc34be478d09c4d16009e665e020ad0fcd0deea
> > patch link: https://lore.kernel.org/all/20250626144017.1510594-2-clm@fb.com/
> > patch subject: [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
> >
> > testcase: unixbench
> > config: x86_64-rhel-9.4
> > compiler: gcc-12
> > test machine: 64 threads 2 sockets Intel(R) Xeon(R) Gold 6346 CPU @ 3.10GHz (Ice Lake) with 256G memory
> > parameters:
> >
> > runtime: 300s
> > nr_task: 100%
> > test: shell1
> > cpufreq_governor: performance
> >
> >
> ...
>
> >
> > commit:
> > 5bc34be478 ("sched/core: Reorganize cgroup bandwidth control interface file writes")
> > ac34cb39e8 ("sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails")
> >
> > 5bc34be478d09c4d ac34cb39e8aea9915ec2f4e08c9
> > ---------------- ---------------------------
> > %stddev %change %stddev
> > \ | \
> ...
>
> > 40.37 +16.9 57.24 mpstat.cpu.all.idle%
>
> This commit inhibits the newidle balance.
When not successful. So when newidle balance is not succeeding to pull
tasks, it is backing off and doing less of it.
> It seems that some workloads
> do not like newlyidle balance, like schbench, which is short duration
> task. While other workloads want the newidle balance to pull at its best
> effort, like unixbench shell test case.
> Just wonder if we can check the sched domain's average utilization to
> decide how hard we should trigger the newly idle balance, or can we check
> the overutilized flag to decide whether we should launch the
> new idle balance, something I was thinking of:
Looking at the actual util signal might be interesting, but as Chris
already noted, overutilized isn't the right thing to look at. Simply
taking rq->cfs.avg.util_avg might be more useful. Very high util and
failure to pull might indicate new-idle just isn't very important /
effective. While low util and failure might mean we should try harder.
Other things to look at:
- if the sysctl_sched_migration_cost limit isn't artificially limiting
actual scanning costs. Eg. very large domains might perhaps have
costs that are genuinely larger than that somewhat random number.
- if despite the apparent failure to pull, we do already have something
to run (eg. wakeups).
- if the 3/2 backoff is perhaps too aggressive vs the 1% per second
decay.
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
2025-07-16 11:25 ` Peter Zijlstra
@ 2025-07-16 15:58 ` Chen, Yu C
0 siblings, 0 replies; 11+ messages in thread
From: Chen, Yu C @ 2025-07-16 15:58 UTC (permalink / raw)
To: Peter Zijlstra
Cc: kernel test robot, Chris Mason, oe-lkp, lkp, linux-kernel,
aubrey.li, vincent.guittot
On 7/16/2025 7:25 PM, Peter Zijlstra wrote:
> On Tue, Jul 15, 2025 at 06:08:43PM +0800, Chen, Yu C wrote:
>> On 7/15/2025 3:08 PM, kernel test robot wrote:
>>>
>>>
>>> Hello,
>>>
>>> kernel test robot noticed a 22.9% regression of unixbench.throughput on:
>>>
>>>
>>> commit: ac34cb39e8aea9915ec2f4e08c979eb2ed1d7561 ("[PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails")
>>> url: https://github.com/intel-lab-lkp/linux/commits/Chris-Mason/sched-fair-bump-sd-max_newidle_lb_cost-when-newidle-balance-fails/20250626-224805
>>> base: https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git 5bc34be478d09c4d16009e665e020ad0fcd0deea
>>> patch link: https://lore.kernel.org/all/20250626144017.1510594-2-clm@fb.com/
>>> patch subject: [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
>>>
>>> testcase: unixbench
>>> config: x86_64-rhel-9.4
>>> compiler: gcc-12
>>> test machine: 64 threads 2 sockets Intel(R) Xeon(R) Gold 6346 CPU @ 3.10GHz (Ice Lake) with 256G memory
>>> parameters:
>>>
>>> runtime: 300s
>>> nr_task: 100%
>>> test: shell1
>>> cpufreq_governor: performance
>>>
>>>
>> ...
>>
>>>
>>> commit:
>>> 5bc34be478 ("sched/core: Reorganize cgroup bandwidth control interface file writes")
>>> ac34cb39e8 ("sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails")
>>>
>>> 5bc34be478d09c4d ac34cb39e8aea9915ec2f4e08c9
>>> ---------------- ---------------------------
>>> %stddev %change %stddev
>>> \ | \
>> ...
>>
>>> 40.37 +16.9 57.24 mpstat.cpu.all.idle%
>>
>> This commit inhibits the newidle balance.
>
> When not successful. So when newidle balance is not succeeding to pull
> tasks, it is backing off and doing less of it.
>
>> It seems that some workloads
>> do not like newlyidle balance, like schbench, which is short duration
>> task. While other workloads want the newidle balance to pull at its best
>> effort, like unixbench shell test case.
>> Just wonder if we can check the sched domain's average utilization to
>> decide how hard we should trigger the newly idle balance, or can we check
>> the overutilized flag to decide whether we should launch the
>> new idle balance, something I was thinking of:
>
> Looking at the actual util signal might be interesting, but as Chris
> already noted, overutilized isn't the right thing to look at. Simply
> taking rq->cfs.avg.util_avg might be more useful. Very high util and
> failure to pull might indicate new-idle just isn't very important /
> effective. While low util and failure might mean we should try harder.
>
> Other things to look at:
>
> - if the sysctl_sched_migration_cost limit isn't artificially limiting
> actual scanning costs. Eg. very large domains might perhaps have
> costs that are genuinely larger than that somewhat random number.
>
> - if despite the apparent failure to pull, we do already have something
> to run (eg. wakeups).
>
> - if the 3/2 backoff is perhaps too aggressive vs the 1% per second
> decay.
Thanks for the suggestions, let me try to reproduce this issue locally
to see what is the proper way to get it addressed.
thanks,
Chenyu
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
2025-06-26 14:39 [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails Chris Mason
2025-07-10 12:46 ` [tip: sched/core] sched/fair: Bump " tip-bot2 for Chris Mason
2025-07-15 7:08 ` [PATCH v2] sched/fair: bump " kernel test robot
@ 2025-09-07 18:21 ` Ryan Roberts
2025-09-09 7:38 ` Ryan Roberts
2025-09-10 12:29 ` Dietmar Eggemann
2 siblings, 2 replies; 11+ messages in thread
From: Ryan Roberts @ 2025-09-07 18:21 UTC (permalink / raw)
To: Chris Mason, peterz, vincent.guittot, linux-kernel,
Aishwarya Rambhadran
On 26/06/2025 15:39, Chris Mason wrote:
> schbench (https://github.com/masoncl/schbench.git) is showing a
> regression from previous production kernels that bisected down to:
>
> sched/fair: Remove sysctl_sched_migration_cost condition (c5b0a7eefc)
>
> The schbench command line was:
>
> schbench -L -m 4 -M auto -t 256 -n 0 -r 0 -s 0
>
> This creates 4 message threads pinned to CPUs 0-3, and 256x4 worker
> threads spread across the rest of the CPUs. Neither the worker threads
> or the message threads do any work, they just wake each other up and go
> back to sleep as soon as possible.
>
> The end result is the first 4 CPUs are pegged waking up those 1024
> workers, and the rest of the CPUs are constantly banging in and out of
> idle. If I take a v6.9 Linus kernel and revert that one commit,
> performance goes from 3.4M RPS to 5.4M RPS.
>
> schedstat shows there are ~100x more new idle balance operations, and
> profiling shows the worker threads are spending ~20% of their CPU time
> on new idle balance. schedstats also shows that almost all of these new
> idle balance attemps are failing to find busy groups.
>
> The fix used here is to crank up the cost of the newidle balance whenever it
> fails. Since we don't want sd->max_newidle_lb_cost to grow out of
> control, this also changes update_newidle_cost() to use
> sysctl_sched_migration_cost as the upper limit on max_newidle_lb_cost.
>
> Signed-off-by: Chris Mason <clm@fb.com>
Hi,
I'm seeing a ~25% regression in requests per second for an nginx workload in
6.17-rc4 compared with 6.16, when the number of simulated clients (threads) is
high (1000). Bisection led me to this patch. The workload is running on an
AmpereOne (arm64) system with 192 CPUs. FWIW, I don't see the regression on an
AWS Graviton3 system.
I'm also seeing a 10% regression on the same system for a MySQL workload; but I
haven't yet bisected that one - I'll report back if that turns out to be due to
this too.
I saw that there was a regression raised against this patch by kernel test robot
for unixbench.throughput back in July, but it didn't look like it got resolved.
I can repro this easily so happy to try out any candidate fixes.
Here is the bisect log:
# good: [038d61fd642278bab63ee8ef722c50d10ab01e8f] Linux 6.16
git bisect good 038d61fd642278bab63ee8ef722c50d10ab01e8f
# status: waiting for bad commit, 1 good commit known
# bad: [8f5ae30d69d7543eee0d70083daf4de8fe15d585] Linux 6.17-rc1
git bisect bad 8f5ae30d69d7543eee0d70083daf4de8fe15d585
# bad: [8be4d31cb8aaeea27bde4b7ddb26e28a89062ebf] Merge tag 'net-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
git bisect bad 8be4d31cb8aaeea27bde4b7ddb26e28a89062ebf
# good: [115e74a29b530d121891238e9551c4bcdf7b04b5] Merge tag 'soc-dt-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
git bisect good 115e74a29b530d121891238e9551c4bcdf7b04b5
# good: [49f02e6877d1bec848048dc6366859c30bbc0a04] Octeontx2-af: Debugfs support for firmware data
git bisect good 49f02e6877d1bec848048dc6366859c30bbc0a04
# good: [14bed9bc81bae64db98349319f367bfc7dab0afd] Merge tag 'x86_sev_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
git bisect good 14bed9bc81bae64db98349319f367bfc7dab0afd
# good: [c6dc26df6b4883de63cb237b4070feba92b01a87] Merge tag 'nf-next-25-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next
git bisect good c6dc26df6b4883de63cb237b4070feba92b01a87
# bad: [3bb38c52719baa7f9cdbf200016ed481b4498290] Merge tag 'm68k-for-v6.17-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k
git bisect bad 3bb38c52719baa7f9cdbf200016ed481b4498290
# bad: [bcb48dd3b344592cc33732de640b99264c073df1] Merge tag 'perf-core-2025-07-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
git bisect bad bcb48dd3b344592cc33732de640b99264c073df1
# good: [d403a3689af5c3a3e3ac6e282958d0eaa69ca47f] sched/fair: Move max_cfs_quota_period decl and default_cfs_period() def from fair.c to sched.h
git bisect good d403a3689af5c3a3e3ac6e282958d0eaa69ca47f
# bad: [9fdb12c88e9ba75e2d831fb397dd27f03a534968] tools/sched: Add root_domains_dump.py which dumps root domains info
git bisect bad 9fdb12c88e9ba75e2d831fb397dd27f03a534968
# bad: [570c8efd5eb79c3725ba439ce105ed1bedc5acd9] sched/psi: Optimize psi_group_change() cpu_clock() usage
git bisect bad 570c8efd5eb79c3725ba439ce105ed1bedc5acd9
# good: [11867144ff81ab98f4b11c99716c3e8b714b8755] rust: sync: Mark PollCondVar::drop() inline
git bisect good 11867144ff81ab98f4b11c99716c3e8b714b8755
# good: [7e611710acf966df1e14bcf4e067385e38e549a1] rust: task: Add Rust version of might_sleep()
git bisect good 7e611710acf966df1e14bcf4e067385e38e549a1
# bad: [155213a2aed42c85361bf4f5c817f5cb68951c3b] sched/fair: Bump sd->max_newidle_lb_cost when newidle balance fails
git bisect bad 155213a2aed42c85361bf4f5c817f5cb68951c3b
# good: [d398a68e8bcf430e231cccfbaa27cb25a7a6f224] Merge tag 'rust-sched.2025.06.24' of git://git.kernel.org/pub/scm/linux/kernel/git/boqun/linux into sched/core
git bisect good d398a68e8bcf430e231cccfbaa27cb25a7a6f224
# first bad commit: [155213a2aed42c85361bf4f5c817f5cb68951c3b] sched/fair: Bump sd->max_newidle_lb_cost when newidle balance fails
Thanks,
Ryan
> ---
> kernel/sched/fair.c | 19 ++++++++++++++++---
> 1 file changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 7a14da5396fb2..042ab0863ccc0 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -12174,8 +12174,14 @@ static inline bool update_newidle_cost(struct sched_domain *sd, u64 cost)
> /*
> * Track max cost of a domain to make sure to not delay the
> * next wakeup on the CPU.
> + *
> + * sched_balance_newidle() bumps the cost whenever newidle
> + * balance fails, and we don't want things to grow out of
> + * control. Use the sysctl_sched_migration_cost as the upper
> + * limit, plus a litle extra to avoid off by ones.
> */
> - sd->max_newidle_lb_cost = cost;
> + sd->max_newidle_lb_cost =
> + min(cost, sysctl_sched_migration_cost + 200);
> sd->last_decay_max_lb_cost = jiffies;
> } else if (time_after(jiffies, sd->last_decay_max_lb_cost + HZ)) {
> /*
> @@ -12867,10 +12873,17 @@ static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf)
>
> t1 = sched_clock_cpu(this_cpu);
> domain_cost = t1 - t0;
> - update_newidle_cost(sd, domain_cost);
> -
> curr_cost += domain_cost;
> t0 = t1;
> +
> + /*
> + * Failing newidle means it is not effective;
> + * bump the cost so we end up doing less of it.
> + */
> + if (!pulled_task)
> + domain_cost = (3 * sd->max_newidle_lb_cost) / 2;
> +
> + update_newidle_cost(sd, domain_cost);
> }
>
> /*
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
2025-09-07 18:21 ` Ryan Roberts
@ 2025-09-09 7:38 ` Ryan Roberts
2025-09-10 12:29 ` Dietmar Eggemann
1 sibling, 0 replies; 11+ messages in thread
From: Ryan Roberts @ 2025-09-09 7:38 UTC (permalink / raw)
To: Chris Mason, peterz, vincent.guittot, linux-kernel,
Aishwarya Rambhadran
On 07/09/2025 19:21, Ryan Roberts wrote:
> On 26/06/2025 15:39, Chris Mason wrote:
>> schbench (https://github.com/masoncl/schbench.git) is showing a
>> regression from previous production kernels that bisected down to:
>>
>> sched/fair: Remove sysctl_sched_migration_cost condition (c5b0a7eefc)
>>
>> The schbench command line was:
>>
>> schbench -L -m 4 -M auto -t 256 -n 0 -r 0 -s 0
>>
>> This creates 4 message threads pinned to CPUs 0-3, and 256x4 worker
>> threads spread across the rest of the CPUs. Neither the worker threads
>> or the message threads do any work, they just wake each other up and go
>> back to sleep as soon as possible.
>>
>> The end result is the first 4 CPUs are pegged waking up those 1024
>> workers, and the rest of the CPUs are constantly banging in and out of
>> idle. If I take a v6.9 Linus kernel and revert that one commit,
>> performance goes from 3.4M RPS to 5.4M RPS.
>>
>> schedstat shows there are ~100x more new idle balance operations, and
>> profiling shows the worker threads are spending ~20% of their CPU time
>> on new idle balance. schedstats also shows that almost all of these new
>> idle balance attemps are failing to find busy groups.
>>
>> The fix used here is to crank up the cost of the newidle balance whenever it
>> fails. Since we don't want sd->max_newidle_lb_cost to grow out of
>> control, this also changes update_newidle_cost() to use
>> sysctl_sched_migration_cost as the upper limit on max_newidle_lb_cost.
>>
>> Signed-off-by: Chris Mason <clm@fb.com>
>
> Hi,
>
> I'm seeing a ~25% regression in requests per second for an nginx workload in
> 6.17-rc4 compared with 6.16, when the number of simulated clients (threads) is
> high (1000). Bisection led me to this patch. The workload is running on an
> AmpereOne (arm64) system with 192 CPUs. FWIW, I don't see the regression on an
> AWS Graviton3 system.
>
> I'm also seeing a 10% regression on the same system for a MySQL workload; but I
> haven't yet bisected that one - I'll report back if that turns out to be due to
> this too.
Just to add that this MySQL workload regression was also bisected to the same patch.
Thanks,
Ryan
>
> I saw that there was a regression raised against this patch by kernel test robot
> for unixbench.throughput back in July, but it didn't look like it got resolved.
>
> I can repro this easily so happy to try out any candidate fixes.
>
>
> Here is the bisect log:
>
> # good: [038d61fd642278bab63ee8ef722c50d10ab01e8f] Linux 6.16
> git bisect good 038d61fd642278bab63ee8ef722c50d10ab01e8f
> # status: waiting for bad commit, 1 good commit known
> # bad: [8f5ae30d69d7543eee0d70083daf4de8fe15d585] Linux 6.17-rc1
> git bisect bad 8f5ae30d69d7543eee0d70083daf4de8fe15d585
> # bad: [8be4d31cb8aaeea27bde4b7ddb26e28a89062ebf] Merge tag 'net-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
> git bisect bad 8be4d31cb8aaeea27bde4b7ddb26e28a89062ebf
> # good: [115e74a29b530d121891238e9551c4bcdf7b04b5] Merge tag 'soc-dt-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
> git bisect good 115e74a29b530d121891238e9551c4bcdf7b04b5
> # good: [49f02e6877d1bec848048dc6366859c30bbc0a04] Octeontx2-af: Debugfs support for firmware data
> git bisect good 49f02e6877d1bec848048dc6366859c30bbc0a04
> # good: [14bed9bc81bae64db98349319f367bfc7dab0afd] Merge tag 'x86_sev_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
> git bisect good 14bed9bc81bae64db98349319f367bfc7dab0afd
> # good: [c6dc26df6b4883de63cb237b4070feba92b01a87] Merge tag 'nf-next-25-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next
> git bisect good c6dc26df6b4883de63cb237b4070feba92b01a87
> # bad: [3bb38c52719baa7f9cdbf200016ed481b4498290] Merge tag 'm68k-for-v6.17-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k
> git bisect bad 3bb38c52719baa7f9cdbf200016ed481b4498290
> # bad: [bcb48dd3b344592cc33732de640b99264c073df1] Merge tag 'perf-core-2025-07-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
> git bisect bad bcb48dd3b344592cc33732de640b99264c073df1
> # good: [d403a3689af5c3a3e3ac6e282958d0eaa69ca47f] sched/fair: Move max_cfs_quota_period decl and default_cfs_period() def from fair.c to sched.h
> git bisect good d403a3689af5c3a3e3ac6e282958d0eaa69ca47f
> # bad: [9fdb12c88e9ba75e2d831fb397dd27f03a534968] tools/sched: Add root_domains_dump.py which dumps root domains info
> git bisect bad 9fdb12c88e9ba75e2d831fb397dd27f03a534968
> # bad: [570c8efd5eb79c3725ba439ce105ed1bedc5acd9] sched/psi: Optimize psi_group_change() cpu_clock() usage
> git bisect bad 570c8efd5eb79c3725ba439ce105ed1bedc5acd9
> # good: [11867144ff81ab98f4b11c99716c3e8b714b8755] rust: sync: Mark PollCondVar::drop() inline
> git bisect good 11867144ff81ab98f4b11c99716c3e8b714b8755
> # good: [7e611710acf966df1e14bcf4e067385e38e549a1] rust: task: Add Rust version of might_sleep()
> git bisect good 7e611710acf966df1e14bcf4e067385e38e549a1
> # bad: [155213a2aed42c85361bf4f5c817f5cb68951c3b] sched/fair: Bump sd->max_newidle_lb_cost when newidle balance fails
> git bisect bad 155213a2aed42c85361bf4f5c817f5cb68951c3b
> # good: [d398a68e8bcf430e231cccfbaa27cb25a7a6f224] Merge tag 'rust-sched.2025.06.24' of git://git.kernel.org/pub/scm/linux/kernel/git/boqun/linux into sched/core
> git bisect good d398a68e8bcf430e231cccfbaa27cb25a7a6f224
> # first bad commit: [155213a2aed42c85361bf4f5c817f5cb68951c3b] sched/fair: Bump sd->max_newidle_lb_cost when newidle balance fails
>
>
> Thanks,
> Ryan
>
>
>
>> ---
>> kernel/sched/fair.c | 19 ++++++++++++++++---
>> 1 file changed, 16 insertions(+), 3 deletions(-)
>>
>> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
>> index 7a14da5396fb2..042ab0863ccc0 100644
>> --- a/kernel/sched/fair.c
>> +++ b/kernel/sched/fair.c
>> @@ -12174,8 +12174,14 @@ static inline bool update_newidle_cost(struct sched_domain *sd, u64 cost)
>> /*
>> * Track max cost of a domain to make sure to not delay the
>> * next wakeup on the CPU.
>> + *
>> + * sched_balance_newidle() bumps the cost whenever newidle
>> + * balance fails, and we don't want things to grow out of
>> + * control. Use the sysctl_sched_migration_cost as the upper
>> + * limit, plus a litle extra to avoid off by ones.
>> */
>> - sd->max_newidle_lb_cost = cost;
>> + sd->max_newidle_lb_cost =
>> + min(cost, sysctl_sched_migration_cost + 200);
>> sd->last_decay_max_lb_cost = jiffies;
>> } else if (time_after(jiffies, sd->last_decay_max_lb_cost + HZ)) {
>> /*
>> @@ -12867,10 +12873,17 @@ static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf)
>>
>> t1 = sched_clock_cpu(this_cpu);
>> domain_cost = t1 - t0;
>> - update_newidle_cost(sd, domain_cost);
>> -
>> curr_cost += domain_cost;
>> t0 = t1;
>> +
>> + /*
>> + * Failing newidle means it is not effective;
>> + * bump the cost so we end up doing less of it.
>> + */
>> + if (!pulled_task)
>> + domain_cost = (3 * sd->max_newidle_lb_cost) / 2;
>> +
>> + update_newidle_cost(sd, domain_cost);
>> }
>>
>> /*
>
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails
2025-09-07 18:21 ` Ryan Roberts
2025-09-09 7:38 ` Ryan Roberts
@ 2025-09-10 12:29 ` Dietmar Eggemann
1 sibling, 0 replies; 11+ messages in thread
From: Dietmar Eggemann @ 2025-09-10 12:29 UTC (permalink / raw)
To: Ryan Roberts, Chris Mason, peterz, vincent.guittot, linux-kernel,
Aishwarya Rambhadran
On 07.09.25 20:21, Ryan Roberts wrote:
> On 26/06/2025 15:39, Chris Mason wrote:
[...]
> I'm seeing a ~25% regression in requests per second for an nginx workload in
> 6.17-rc4 compared with 6.16, when the number of simulated clients (threads) is
> high (1000). Bisection led me to this patch. The workload is running on an
> AmpereOne (arm64) system with 192 CPUs. FWIW, I don't see the regression on an
> AWS Graviton3 system.
Can you look for any sched domain hierarchy differences between
AmpereOne and Grav3?
I assume Grav3 is bare-metal?
> I'm also seeing a 10% regression on the same system for a MySQL workload; but I
> haven't yet bisected that one - I'll report back if that turns out to be due to
> this too.
Is this the hammerdb test in which the SUT hosts the mysqld? Which
params (#Virtual Users, #Warehouses, ...) were you using?
> I saw that there was a regression raised against this patch by kernel test robot
> for unixbench.throughput back in July, but it didn't look like it got resolved.
Can you run the unixbench shell1 test on AmpereOne to see if the
regression in nginx is related to this unixbench test?
[...]
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2025-09-10 12:29 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-06-26 14:39 [PATCH v2] sched/fair: bump sd->max_newidle_lb_cost when newidle balance fails Chris Mason
2025-07-10 12:46 ` [tip: sched/core] sched/fair: Bump " tip-bot2 for Chris Mason
2025-07-15 7:08 ` [PATCH v2] sched/fair: bump " kernel test robot
2025-07-15 10:08 ` Chen, Yu C
2025-07-15 15:38 ` Chris Mason
2025-07-16 15:56 ` Chen, Yu C
2025-07-16 11:25 ` Peter Zijlstra
2025-07-16 15:58 ` Chen, Yu C
2025-09-07 18:21 ` Ryan Roberts
2025-09-09 7:38 ` Ryan Roberts
2025-09-10 12:29 ` Dietmar Eggemann
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