lkml.org 
[lkml]   [2023]   [Jan]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] sched/fair: sanitize vruntime of entity being placed
Hi Roman,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on tip/sched/core]
[also build test WARNING on linus/master v6.2-rc5 next-20230127]
[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#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Roman-Kagan/sched-fair-sanitize-vruntime-of-entity-being-placed/20230128-130846
patch link: https://lore.kernel.org/r/20230127163230.3339408-1-rkagan%40amazon.de
patch subject: [PATCH] sched/fair: sanitize vruntime of entity being placed
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20230128/202301281410.4cvSCADA-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 12.1.0
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/intel-lab-lkp/linux/commit/2db31a18bcb88c280481672d7721f7e003d8df5a
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Roman-Kagan/sched-fair-sanitize-vruntime-of-entity-being-placed/20230128-130846
git checkout 2db31a18bcb88c280481672d7721f7e003d8df5a
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash kernel/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

kernel/sched/fair.c:688:5: warning: no previous prototype for 'sched_update_scaling' [-Wmissing-prototypes]
688 | int sched_update_scaling(void)
| ^~~~~~~~~~~~~~~~~~~~
kernel/sched/fair.c: In function 'place_entity':
>> kernel/sched/fair.c:4697:34: warning: integer overflow in expression of type 'long int' results in '-129542144' [-Woverflow]
4697 | if ((s64)sleep_time > 60 * NSEC_PER_SEC)
| ^


vim +4697 kernel/sched/fair.c

4654
4655 static void
4656 place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
4657 {
4658 u64 vruntime = cfs_rq->min_vruntime;
4659 u64 sleep_time;
4660
4661 /*
4662 * The 'current' period is already promised to the current tasks,
4663 * however the extra weight of the new task will slow them down a
4664 * little, place the new task so that it fits in the slot that
4665 * stays open at the end.
4666 */
4667 if (initial && sched_feat(START_DEBIT))
4668 vruntime += sched_vslice(cfs_rq, se);
4669
4670 /* sleeps up to a single latency don't count. */
4671 if (!initial) {
4672 unsigned long thresh;
4673
4674 if (se_is_idle(se))
4675 thresh = sysctl_sched_min_granularity;
4676 else
4677 thresh = sysctl_sched_latency;
4678
4679 /*
4680 * Halve their sleep time's effect, to allow
4681 * for a gentler effect of sleepers:
4682 */
4683 if (sched_feat(GENTLE_FAIR_SLEEPERS))
4684 thresh >>= 1;
4685
4686 vruntime -= thresh;
4687 }
4688
4689 /*
4690 * Pull vruntime of the entity being placed to the base level of
4691 * cfs_rq, to prevent boosting it if placed backwards. If the entity
4692 * slept for a long time, don't even try to compare its vruntime with
4693 * the base as it may be too far off and the comparison may get
4694 * inversed due to s64 overflow.
4695 */
4696 sleep_time = rq_clock_task(rq_of(cfs_rq)) - se->exec_start;
> 4697 if ((s64)sleep_time > 60 * NSEC_PER_SEC)
4698 se->vruntime = vruntime;
4699 else
4700 se->vruntime = max_vruntime(se->vruntime, vruntime);
4701 }
4702

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

\
 
 \ /
  Last update: 2023-03-27 00:00    [W:0.024 / U:0.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site