Re: [PATCH 1/2] sched/fair: keep load_avg and load_sum synced
From: kernel test robot
Date: Thu May 27 2021 - 09:40:49 EST
Hi Vincent,
I love your patch! Perhaps something to improve:
[auto build test WARNING on tip/sched/core]
[also build test WARNING on tip/master linux/master linus/master v5.13-rc3 next-20210527]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Vincent-Guittot/schd-fair-fix-stalled-cfs_rq-tg_load_avg_contrib/20210527-203115
base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git a8ea6fc9b089156d9230bfeef964dd9be101a4a9
config: s390-randconfig-c024-20210527 (attached as .config)
compiler: s390-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/725167b3ef5a796c98add27cb21e543c7b72cf0e
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Vincent-Guittot/schd-fair-fix-stalled-cfs_rq-tg_load_avg_contrib/20210527-203115
git checkout 725167b3ef5a796c98add27cb21e543c7b72cf0e
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=s390
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>
All warnings (new ones prefixed by >>):
kernel/sched/fair.c: In function 'update_tg_cfs_load':
>> kernel/sched/fair.c:3459:6: warning: variable 'delta_sum' set but not used [-Wunused-but-set-variable]
3459 | s64 delta_sum;
| ^~~~~~~~~
vim +/delta_sum +3459 kernel/sched/fair.c
9f68395333ad7f Vincent Guittot 2020-02-24 3452
09a43ace1f986b Vincent Guittot 2016-11-08 3453 static inline void
0dacee1bfa70e1 Vincent Guittot 2020-02-24 3454 update_tg_cfs_load(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq *gcfs_rq)
09a43ace1f986b Vincent Guittot 2016-11-08 3455 {
a4c3c04974d648 Vincent Guittot 2017-11-16 3456 long delta_avg, running_sum, runnable_sum = gcfs_rq->prop_runnable_sum;
0dacee1bfa70e1 Vincent Guittot 2020-02-24 3457 unsigned long load_avg;
0dacee1bfa70e1 Vincent Guittot 2020-02-24 3458 u64 load_sum = 0;
a4c3c04974d648 Vincent Guittot 2017-11-16 @3459 s64 delta_sum;
95d685935a2edf Vincent Guittot 2020-05-06 3460 u32 divider;
09a43ace1f986b Vincent Guittot 2016-11-08 3461
0e2d2aaaae52c2 Peter Zijlstra 2017-05-08 3462 if (!runnable_sum)
0e2d2aaaae52c2 Peter Zijlstra 2017-05-08 3463 return;
09a43ace1f986b Vincent Guittot 2016-11-08 3464
0e2d2aaaae52c2 Peter Zijlstra 2017-05-08 3465 gcfs_rq->prop_runnable_sum = 0;
09a43ace1f986b Vincent Guittot 2016-11-08 3466
95d685935a2edf Vincent Guittot 2020-05-06 3467 /*
95d685935a2edf Vincent Guittot 2020-05-06 3468 * cfs_rq->avg.period_contrib can be used for both cfs_rq and se.
95d685935a2edf Vincent Guittot 2020-05-06 3469 * See ___update_load_avg() for details.
95d685935a2edf Vincent Guittot 2020-05-06 3470 */
87e867b4269f29 Vincent Guittot 2020-06-12 3471 divider = get_pelt_divider(&cfs_rq->avg);
95d685935a2edf Vincent Guittot 2020-05-06 3472
a4c3c04974d648 Vincent Guittot 2017-11-16 3473 if (runnable_sum >= 0) {
a4c3c04974d648 Vincent Guittot 2017-11-16 3474 /*
a4c3c04974d648 Vincent Guittot 2017-11-16 3475 * Add runnable; clip at LOAD_AVG_MAX. Reflects that until
a4c3c04974d648 Vincent Guittot 2017-11-16 3476 * the CPU is saturated running == runnable.
a4c3c04974d648 Vincent Guittot 2017-11-16 3477 */
a4c3c04974d648 Vincent Guittot 2017-11-16 3478 runnable_sum += se->avg.load_sum;
95d685935a2edf Vincent Guittot 2020-05-06 3479 runnable_sum = min_t(long, runnable_sum, divider);
a4c3c04974d648 Vincent Guittot 2017-11-16 3480 } else {
a4c3c04974d648 Vincent Guittot 2017-11-16 3481 /*
a4c3c04974d648 Vincent Guittot 2017-11-16 3482 * Estimate the new unweighted runnable_sum of the gcfs_rq by
a4c3c04974d648 Vincent Guittot 2017-11-16 3483 * assuming all tasks are equally runnable.
a4c3c04974d648 Vincent Guittot 2017-11-16 3484 */
a4c3c04974d648 Vincent Guittot 2017-11-16 3485 if (scale_load_down(gcfs_rq->load.weight)) {
a4c3c04974d648 Vincent Guittot 2017-11-16 3486 load_sum = div_s64(gcfs_rq->avg.load_sum,
a4c3c04974d648 Vincent Guittot 2017-11-16 3487 scale_load_down(gcfs_rq->load.weight));
a4c3c04974d648 Vincent Guittot 2017-11-16 3488 }
a4c3c04974d648 Vincent Guittot 2017-11-16 3489
a4c3c04974d648 Vincent Guittot 2017-11-16 3490 /* But make sure to not inflate se's runnable */
a4c3c04974d648 Vincent Guittot 2017-11-16 3491 runnable_sum = min(se->avg.load_sum, load_sum);
a4c3c04974d648 Vincent Guittot 2017-11-16 3492 }
a4c3c04974d648 Vincent Guittot 2017-11-16 3493
a4c3c04974d648 Vincent Guittot 2017-11-16 3494 /*
a4c3c04974d648 Vincent Guittot 2017-11-16 3495 * runnable_sum can't be lower than running_sum
23127296889fe8 Vincent Guittot 2019-01-23 3496 * Rescale running sum to be in the same range as runnable sum
23127296889fe8 Vincent Guittot 2019-01-23 3497 * running_sum is in [0 : LOAD_AVG_MAX << SCHED_CAPACITY_SHIFT]
23127296889fe8 Vincent Guittot 2019-01-23 3498 * runnable_sum is in [0 : LOAD_AVG_MAX]
a4c3c04974d648 Vincent Guittot 2017-11-16 3499 */
23127296889fe8 Vincent Guittot 2019-01-23 3500 running_sum = se->avg.util_sum >> SCHED_CAPACITY_SHIFT;
a4c3c04974d648 Vincent Guittot 2017-11-16 3501 runnable_sum = max(runnable_sum, running_sum);
a4c3c04974d648 Vincent Guittot 2017-11-16 3502
0e2d2aaaae52c2 Peter Zijlstra 2017-05-08 3503 load_sum = (s64)se_weight(se) * runnable_sum;
95d685935a2edf Vincent Guittot 2020-05-06 3504 load_avg = div_s64(load_sum, divider);
09a43ace1f986b Vincent Guittot 2016-11-08 3505
a4c3c04974d648 Vincent Guittot 2017-11-16 3506 delta_sum = load_sum - (s64)se_weight(se) * se->avg.load_sum;
a4c3c04974d648 Vincent Guittot 2017-11-16 3507 delta_avg = load_avg - se->avg.load_avg;
09a43ace1f986b Vincent Guittot 2016-11-08 3508
a4c3c04974d648 Vincent Guittot 2017-11-16 3509 se->avg.load_sum = runnable_sum;
a4c3c04974d648 Vincent Guittot 2017-11-16 3510 se->avg.load_avg = load_avg;
a4c3c04974d648 Vincent Guittot 2017-11-16 3511 add_positive(&cfs_rq->avg.load_avg, delta_avg);
725167b3ef5a79 Vincent Guittot 2021-05-27 3512 cfs_rq->avg.load_sum = cfs_rq->avg.load_avg * divider;
725167b3ef5a79 Vincent Guittot 2021-05-27 3513
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
Attachment:
.config.gz
Description: application/gzip