On Thu, 2008-01-24 at 19:46 +1100, Benjamin Herrenschmidt wrote:
> Could the fact that our sched_clock() returns utter crap if called
> before time_init() explain the problem ?
I don't think so. I've confirmed that it gets called exactly once before
time_init(), but it just returns 0 then, which I don't think should be a
problem.
Also, I'm attaching two copies of /proc/sched_debug obtained with
sudo -b -u nobody nice -n 19 sh -c 'while true; do true; done'
&& cat /proc/sched_debug >/tmp/sched_debug.before && sleep 20 &&
cat /proc/sched_debug >/tmp/sched_debug.after && sudo -u nobody
killall sh
Looking at the diff below, the clock appears quite accurate.
Peter or Ingo, maybe you notice something else odd with these or have
other ideas for what conditions could cause niced processes to have such
an impact on interactivity?
--- /home/michdaen/sched_debug.before 2008-01-25 09:40:34.000000000 +0100
+++ /home/michdaen/sched_debug.after 2008-01-25 09:40:34.000000000 +0100
@@ -1,5 +1,5 @@
Sched Debug Version: v0.07, 2.6.24-rc8 #4
-now at 204890.233650 msecs
+now at 224908.343840 msecs
.sysctl_sched_latency : 20.000000
.sysctl_sched_min_granularity : 4.000000
.sysctl_sched_wakeup_granularity : 10.000000
@@ -8,56 +8,56 @@ now at 204890.233650 msecs
.sysctl_sched_features : 7
cpu#0
- .nr_running : 6
- .load : 9971
- .nr_switches : 133199
- .nr_load_updates : 80363
- .nr_uninterruptible : 2
- .jiffies : 4294872186
+ .nr_running : 5
+ .load : 4364
+ .nr_switches : 142978
+ .nr_load_updates : 100239
+ .nr_uninterruptible : 0
+ .jiffies : 4294892204
.next_balance : 0.000000
- .curr->pid : 4736
- .clock : 80363.072863
+ .curr->pid : 4746
+ .clock : 100239.072955
.idle_clock : 0.000000
- .prev_clock_raw : 204876.445696
+ .prev_clock_raw : 224892.259968
.clock_warps : 0
- .clock_overflows : 114542
+ .clock_overflows : 119985
.clock_deep_idle_events : 0
.clock_max_delta : 0.999936
- .cpu_load[0] : 9971
- .cpu_load[1] : 9948
- .cpu_load[2] : 9733
- .cpu_load[3] : 8396
- .cpu_load[4] : 5996
+ .cpu_load[0] : 4364
+ .cpu_load[1] : 3979
+ .cpu_load[2] : 3443
+ .cpu_load[3] : 3331
+ .cpu_load[4] : 3268
cfs_rq
- .exec_clock : 60747.682602
- .MIN_vruntime : 35455.964402
- .min_vruntime : 35455.964402
- .max_vruntime : 35455.964402
- .spread : 0.000000
+ .exec_clock : 80597.780820
+ .MIN_vruntime : 54813.436178
+ .min_vruntime : 54813.436178
+ .max_vruntime : 54818.646546
+ .spread : 5.210368
.spread0 : 0.000000
- .nr_running : 2
- .load : 3072
+ .nr_running : 3
+ .load : 4096
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
- .exec_clock : 1.407424
- .MIN_vruntime : 0.000001
- .min_vruntime : 35455.964402
- .max_vruntime : 0.000001
+ .exec_clock : 19353.983950
+ .MIN_vruntime : 1362837.967264
+ .min_vruntime : 54813.436178
+ .max_vruntime : 1362837.967264
.spread : 0.000000
.spread0 : 0.000000
- .nr_running : 0
- .load : 0
+ .nr_running : 1
+ .load : 15
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
- .exec_clock : 9247.295261
- .MIN_vruntime : 41795.173040
- .min_vruntime : 35455.964402
- .max_vruntime : 41795.173040
+ .exec_clock : 9397.906333
+ .MIN_vruntime : 41843.822192
+ .min_vruntime : 54813.436178
+ .max_vruntime : 41843.822192
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 2
@@ -68,7 +68,7 @@ cfs_rq
cfs_rq
.exec_clock : 0.997824
.MIN_vruntime : 0.000001
- .min_vruntime : 35455.964402
+ .min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
@@ -78,9 +78,9 @@ cfs_rq
.nr_spread_over : 0
cfs_rq
- .exec_clock : 84.409635
+ .exec_clock : 85.106979
.MIN_vruntime : 0.000001
- .min_vruntime : 35455.964402
+ .min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
@@ -90,9 +90,9 @@ cfs_rq
.nr_spread_over : 0
cfs_rq
- .exec_clock : 93.714624
+ .exec_clock : 94.005568
.MIN_vruntime : 0.000001
- .min_vruntime : 35455.964402
+ .min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
@@ -104,7 +104,7 @@ cfs_rq
cfs_rq
.exec_clock : 76.941956
.MIN_vruntime : 0.000001
- .min_vruntime : 35455.964402
+ .min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
@@ -114,9 +114,9 @@ cfs_rq
.nr_spread_over : 0
cfs_rq
- .exec_clock : 489.676070
+ .exec_clock : 496.666022
.MIN_vruntime : 0.000001
- .min_vruntime : 35455.964402
+ .min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
@@ -126,9 +126,9 @@ cfs_rq
.nr_spread_over : 0
cfs_rq
- .exec_clock : 6.610804
+ .exec_clock : 7.357556
.MIN_vruntime : 0.000001
- .min_vruntime : 35455.964402
+ .min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
@@ -140,7 +140,7 @@ cfs_rq
cfs_rq
.exec_clock : 9.548608
.MIN_vruntime : 0.000001
- .min_vruntime : 35455.964402
+ .min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
@@ -152,7 +152,7 @@ cfs_rq
cfs_rq
.exec_clock : 130.004741
.MIN_vruntime : 0.000001
- .min_vruntime : 35455.964402
+ .min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
@@ -164,7 +164,7 @@ cfs_rq
cfs_rq
.exec_clock : 5.477635
.MIN_vruntime : 0.000001
- .min_vruntime : 35455.964402
+ .min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
@@ -174,24 +174,23 @@ cfs_rq
.nr_spread_over : 0
cfs_rq
- .exec_clock : 47873.754074
- .MIN_vruntime : 41804.982498
- .min_vruntime : 35455.964402
- .max_vruntime : 41827.144008
- .spread : 22.161510
+ .exec_clock : 48211.939702
+ .MIN_vruntime : 42001.676760
+ .min_vruntime : 54813.436178
+ .max_vruntime : 42013.220923
+ .spread : 11.544163
.spread0 : 0.000000
- .nr_running : 4
- .load : 7923
+ .nr_running : 2
+ .load : 2301
.bkl_count : 0
.nr_spread_over : 8
runnable tasks:
task PID tree-key switches prio exec-runtime
sum-exec sum-sleep
----------------------------------------------------------------------------------------------------------
- kblockd/0 61 41804.982498 5110 115 41804.982498
24.883015 78433.943969
- udevd 1304 41827.144008 686 116 41827.144008
425.666176 63782.106879
- pbbuttonsd 3878 41805.034397 20351 120 41805.034397
453.425277 41231.848603
- Xorg 4574 41824.962717 12488 119 41824.962717
4933.764004 24971.603455
- zsh 4675 41795.173040 631 120 41795.173040
301.572431 24901.348163
-R cat 4736 41787.850967 0 120 41787.850967
3.696000 0.000000
+ pbbuttonsd 3878 42001.676760 22659 120 42001.676760
506.463055 52940.745088
+ Xorg 4574 42013.220923 15439 119 42013.220923
5168.535269 27513.009418
+ zsh 4675 41843.822192 634 120 41843.822192
302.744207 44763.221535
+ sh 4734 1362837.967264 2791 139 1362837.967264
19352.994638 47.795532
+R cat 4746 41816.398384 0 120 41816.398384
2.149568 0.000000
--
Earthling Michel Dänzer | http://tungstengraphics.com
Libre software enthusiast | Debian, X and DRI developer
Sched Debug Version: v0.07, 2.6.24-rc8 #4
now at 224908.343840 msecs
.sysctl_sched_latency : 20.000000
.sysctl_sched_min_granularity : 4.000000
.sysctl_sched_wakeup_granularity : 10.000000
.sysctl_sched_batch_wakeup_granularity : 10.000000
.sysctl_sched_child_runs_first : 0.000001
.sysctl_sched_features : 7
cpu#0
.nr_running : 5
.load : 4364
.nr_switches : 142978
.nr_load_updates : 100239
.nr_uninterruptible : 0
.jiffies : 4294892204
.next_balance : 0.000000
.curr->pid : 4746
.clock : 100239.072955
.idle_clock : 0.000000
.prev_clock_raw : 224892.259968
.clock_warps : 0
.clock_overflows : 119985
.clock_deep_idle_events : 0
.clock_max_delta : 0.999936
.cpu_load[0] : 4364
.cpu_load[1] : 3979
.cpu_load[2] : 3443
.cpu_load[3] : 3331
.cpu_load[4] : 3268
cfs_rq
.exec_clock : 80597.780820
.MIN_vruntime : 54813.436178
.min_vruntime : 54813.436178
.max_vruntime : 54818.646546
.spread : 5.210368
.spread0 : 0.000000
.nr_running : 3
.load : 4096
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 19353.983950
.MIN_vruntime : 1362837.967264
.min_vruntime : 54813.436178
.max_vruntime : 1362837.967264
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 1
.load : 15
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 9397.906333
.MIN_vruntime : 41843.822192
.min_vruntime : 54813.436178
.max_vruntime : 41843.822192
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 2
.load : 2048
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 0.997824
.MIN_vruntime : 0.000001
.min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 85.106979
.MIN_vruntime : 0.000001
.min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 94.005568
.MIN_vruntime : 0.000001
.min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 76.941956
.MIN_vruntime : 0.000001
.min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 496.666022
.MIN_vruntime : 0.000001
.min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 7.357556
.MIN_vruntime : 0.000001
.min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 9.548608
.MIN_vruntime : 0.000001
.min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 130.004741
.MIN_vruntime : 0.000001
.min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 5.477635
.MIN_vruntime : 0.000001
.min_vruntime : 54813.436178
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 48211.939702
.MIN_vruntime : 42001.676760
.min_vruntime : 54813.436178
.max_vruntime : 42013.220923
.spread : 11.544163
.spread0 : 0.000000
.nr_running : 2
.load : 2301
.bkl_count : 0
.nr_spread_over : 8
runnable tasks:
task PID tree-key switches prio exec-runtime
sum-exec sum-sleep
----------------------------------------------------------------------------------------------------------
pbbuttonsd 3878 42001.676760 22659 120 42001.676760
506.463055 52940.745088
Xorg 4574 42013.220923 15439 119 42013.220923
5168.535269 27513.009418
zsh 4675 41843.822192 634 120 41843.822192
302.744207 44763.221535
sh 4734 1362837.967264 2791 139 1362837.967264
19352.994638 47.795532
R cat 4746 41816.398384 0 120 41816.398384
2.149568 0.000000
Sched Debug Version: v0.07, 2.6.24-rc8 #4
now at 204890.233650 msecs
.sysctl_sched_latency : 20.000000
.sysctl_sched_min_granularity : 4.000000
.sysctl_sched_wakeup_granularity : 10.000000
.sysctl_sched_batch_wakeup_granularity : 10.000000
.sysctl_sched_child_runs_first : 0.000001
.sysctl_sched_features : 7
cpu#0
.nr_running : 6
.load : 9971
.nr_switches : 133199
.nr_load_updates : 80363
.nr_uninterruptible : 2
.jiffies : 4294872186
.next_balance : 0.000000
.curr->pid : 4736
.clock : 80363.072863
.idle_clock : 0.000000
.prev_clock_raw : 204876.445696
.clock_warps : 0
.clock_overflows : 114542
.clock_deep_idle_events : 0
.clock_max_delta : 0.999936
.cpu_load[0] : 9971
.cpu_load[1] : 9948
.cpu_load[2] : 9733
.cpu_load[3] : 8396
.cpu_load[4] : 5996
cfs_rq
.exec_clock : 60747.682602
.MIN_vruntime : 35455.964402
.min_vruntime : 35455.964402
.max_vruntime : 35455.964402
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 2
.load : 3072
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 1.407424
.MIN_vruntime : 0.000001
.min_vruntime : 35455.964402
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 9247.295261
.MIN_vruntime : 41795.173040
.min_vruntime : 35455.964402
.max_vruntime : 41795.173040
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 2
.load : 2048
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 0.997824
.MIN_vruntime : 0.000001
.min_vruntime : 35455.964402
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 84.409635
.MIN_vruntime : 0.000001
.min_vruntime : 35455.964402
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 93.714624
.MIN_vruntime : 0.000001
.min_vruntime : 35455.964402
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 76.941956
.MIN_vruntime : 0.000001
.min_vruntime : 35455.964402
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 489.676070
.MIN_vruntime : 0.000001
.min_vruntime : 35455.964402
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 6.610804
.MIN_vruntime : 0.000001
.min_vruntime : 35455.964402
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 9.548608
.MIN_vruntime : 0.000001
.min_vruntime : 35455.964402
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 130.004741
.MIN_vruntime : 0.000001
.min_vruntime : 35455.964402
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 5.477635
.MIN_vruntime : 0.000001
.min_vruntime : 35455.964402
.max_vruntime : 0.000001
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 0
.load : 0
.bkl_count : 0
.nr_spread_over : 0
cfs_rq
.exec_clock : 47873.754074
.MIN_vruntime : 41804.982498
.min_vruntime : 35455.964402
.max_vruntime : 41827.144008
.spread : 22.161510
.spread0 : 0.000000
.nr_running : 4
.load : 7923
.bkl_count : 0
.nr_spread_over : 8
runnable tasks:
task PID tree-key switches prio exec-runtime
sum-exec sum-sleep
----------------------------------------------------------------------------------------------------------
kblockd/0 61 41804.982498 5110 115 41804.982498
24.883015 78433.943969
udevd 1304 41827.144008 686 116 41827.144008
425.666176 63782.106879
pbbuttonsd 3878 41805.034397 20351 120 41805.034397
453.425277 41231.848603
Xorg 4574 41824.962717 12488 119 41824.962717
4933.764004 24971.603455
zsh 4675 41795.173040 631 120 41795.173040
301.572431 24901.348163
R cat 4736 41787.850967 0 120 41787.850967
3.696000 0.000000
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev
