There is a newly introduced hrtimer_setup() which will replace
hrtimer_init(). This new function is similar to the old one, except that it
also sanity-checks and initializes the timer's callback function.

Switch to use this new function.

Signed-off-by: Nam Cao <namcao@linutronix.de>
---
Cc: Peter Zijlstra <peterz@infradead.org>
---
 kernel/sched/core.c     | 3 +--
 kernel/sched/deadline.c | 6 ++----
 kernel/sched/fair.c     | 8 ++++----
 kernel/sched/rt.c       | 5 ++---
 4 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 43e453ab7e20..b86dc57e9dcd 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -903,8 +903,7 @@ static void hrtick_rq_init(struct rq *rq)
 #ifdef CONFIG_SMP
 	INIT_CSD(&rq->hrtick_csd, __hrtick_start, rq);
 #endif
-	hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
-	rq->hrtick_timer.function = hrtick;
+	hrtimer_setup(&rq->hrtick_timer, hrtick, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 }
 #else	/* CONFIG_SCHED_HRTICK */
 static inline void hrtick_clear(struct rq *rq)
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 9ce93d0bf452..cd9d68e87aa0 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1362,8 +1362,7 @@ static void init_dl_task_timer(struct sched_dl_entity *dl_se)
 {
 	struct hrtimer *timer = &dl_se->dl_timer;
 
-	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
-	timer->function = dl_task_timer;
+	hrtimer_setup(timer, dl_task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 }
 
 /*
@@ -1817,8 +1816,7 @@ static void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se)
 {
 	struct hrtimer *timer = &dl_se->inactive_timer;
 
-	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
-	timer->function = inactive_task_timer;
+	hrtimer_setup(timer, inactive_task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 }
 
 #define __node_2_dle(node) \
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 225b31aaee55..c82ada095bca 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6576,14 +6576,14 @@ void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b, struct cfs_bandwidth *paren
 	cfs_b->hierarchical_quota = parent ? parent->hierarchical_quota : RUNTIME_INF;
 
 	INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq);
-	hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
-	cfs_b->period_timer.function = sched_cfs_period_timer;
+	hrtimer_setup(&cfs_b->period_timer, sched_cfs_period_timer, CLOCK_MONOTONIC,
+		      HRTIMER_MODE_ABS_PINNED);
 
 	/* Add a random offset so that timers interleave */
 	hrtimer_set_expires(&cfs_b->period_timer,
 			    get_random_u32_below(cfs_b->period));
-	hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-	cfs_b->slack_timer.function = sched_cfs_slack_timer;
+	hrtimer_setup(&cfs_b->slack_timer, sched_cfs_slack_timer, CLOCK_MONOTONIC,
+		      HRTIMER_MODE_REL);
 	cfs_b->slack_started = false;
 }
 
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 172c588de542..082e3970dc18 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -127,9 +127,8 @@ void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
 
 	raw_spin_lock_init(&rt_b->rt_runtime_lock);
 
-	hrtimer_init(&rt_b->rt_period_timer, CLOCK_MONOTONIC,
-		     HRTIMER_MODE_REL_HARD);
-	rt_b->rt_period_timer.function = sched_rt_period_timer;
+	hrtimer_setup(&rt_b->rt_period_timer, sched_rt_period_timer, CLOCK_MONOTONIC,
+		      HRTIMER_MODE_REL_HARD);
 }
 
 static inline void do_start_rt_bandwidth(struct rt_bandwidth *rt_b)
-- 
2.39.5

Hi Nam,

kernel test robot noticed the following build errors:

[auto build test ERROR on kvm/queue]
[also build test ERROR on tip/sched/core perf-tools-next/perf-tools-next tip/perf/core perf-tools/perf-tools tip/timers/core axboe-block/for-next]
[cannot apply to linus/master kvm/linux-next acme/perf/core v6.12-rc5 next-20241028]
[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/Nam-Cao/KVM-MIPS-Switch-to-use-hrtimer_setup/20241028-154142
base:   https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
patch link:    https://lore.kernel.org/r/f83c7ad9954fce1f84eaec94bb7b58f5f6974fc4.1729864823.git.namcao%40linutronix.de
patch subject: [PATCH 13/31] sched: Switch to use hrtimer_setup()
config: x86_64-rhel-8.3-func (https://download.01.org/0day-ci/archive/20241028/202410282033.n74LbYyl-lkp@intel.com/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/20241028/202410282033.n74LbYyl-lkp@intel.com/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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410282033.n74LbYyl-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from kernel/sched/build_policy.c:52:
   kernel/sched/rt.c: In function 'init_rt_bandwidth':
>> kernel/sched/rt.c:130:9: error: implicit declaration of function 'hrtimer_setup'; did you mean 'timer_setup'? [-Werror=implicit-function-declaration]
     130 |         hrtimer_setup(&rt_b->rt_period_timer, sched_rt_period_timer, CLOCK_MONOTONIC,
         |         ^~~~~~~~~~~~~
         |         timer_setup
   cc1: some warnings being treated as errors


vim +130 kernel/sched/rt.c

   122	
   123	void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
   124	{
   125		rt_b->rt_period = ns_to_ktime(period);
   126		rt_b->rt_runtime = runtime;
   127	
   128		raw_spin_lock_init(&rt_b->rt_runtime_lock);
   129	
 > 130		hrtimer_setup(&rt_b->rt_period_timer, sched_rt_period_timer, CLOCK_MONOTONIC,
   131			      HRTIMER_MODE_REL_HARD);
   132	}
   133	

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