kernel/sched/core.c:1361:21: warning: 'uclamp_mutex' defined but not used
From: kernel test robot
Date: Sat Oct 05 2024 - 14:59:34 EST
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 27cc6fdf720183dce1dbd293483ec5a9cb6b595e
commit: d2d6422f8bd17c6bb205133e290625a564194496 x86: Allow to enable PREEMPT_RT.
date: 3 weeks ago
config: x86_64-buildonly-randconfig-002-20241006 (https://download.01.org/0day-ci/archive/20241006/202410060258.bPl2ZoUo-lkp@xxxxxxxxx/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241006/202410060258.bPl2ZoUo-lkp@xxxxxxxxx/reproduce)
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 <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410060258.bPl2ZoUo-lkp@xxxxxxxxx/
All warnings (new ones prefixed by >>):
In file included from include/linux/seqlock.h:19,
from include/linux/dcache.h:11,
from include/linux/fs.h:8,
from include/linux/highmem.h:5,
from kernel/sched/core.c:10:
>> kernel/sched/core.c:1361:21: warning: 'uclamp_mutex' defined but not used [-Wunused-variable]
1361 | static DEFINE_MUTEX(uclamp_mutex);
| ^~~~~~~~~~~~
include/linux/mutex.h:101:22: note: in definition of macro 'DEFINE_MUTEX'
101 | struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
| ^~~~~~~~~
vim +/uclamp_mutex +1361 kernel/sched/core.c
71f8bd4600521f kernel/sched.c Ingo Molnar 2007-07-09 1349
69842cba9ace84 kernel/sched/core.c Patrick Bellasi 2019-06-21 1350 #ifdef CONFIG_UCLAMP_TASK
2480c093130f64 kernel/sched/core.c Patrick Bellasi 2019-08-22 1351 /*
2480c093130f64 kernel/sched/core.c Patrick Bellasi 2019-08-22 1352 * Serializes updates of utilization clamp values
2480c093130f64 kernel/sched/core.c Patrick Bellasi 2019-08-22 1353 *
2480c093130f64 kernel/sched/core.c Patrick Bellasi 2019-08-22 1354 * The (slow-path) user-space triggers utilization clamp value updates which
2480c093130f64 kernel/sched/core.c Patrick Bellasi 2019-08-22 1355 * can require updates on (fast-path) scheduler's data structures used to
2480c093130f64 kernel/sched/core.c Patrick Bellasi 2019-08-22 1356 * support enqueue/dequeue operations.
2480c093130f64 kernel/sched/core.c Patrick Bellasi 2019-08-22 1357 * While the per-CPU rq lock protects fast-path update operations, user-space
2480c093130f64 kernel/sched/core.c Patrick Bellasi 2019-08-22 1358 * requests are serialized using a mutex to reduce the risk of conflicting
2480c093130f64 kernel/sched/core.c Patrick Bellasi 2019-08-22 1359 * updates or API abuses.
2480c093130f64 kernel/sched/core.c Patrick Bellasi 2019-08-22 1360 */
2480c093130f64 kernel/sched/core.c Patrick Bellasi 2019-08-22 @1361 static DEFINE_MUTEX(uclamp_mutex);
2480c093130f64 kernel/sched/core.c Patrick Bellasi 2019-08-22 1362
:::::: The code at line 1361 was first introduced by commit
:::::: 2480c093130f64ac3a410504fa8b3db1fc4b87ce sched/uclamp: Extend CPU's cgroup controller
:::::: TO: Patrick Bellasi <patrick.bellasi@xxxxxxx>
:::::: CC: Ingo Molnar <mingo@xxxxxxxxxx>
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