diff mbox series

[v6,15/20] sched: Add proxy deactivate helper

Message ID 20231106193524.866104-16-jstultz@google.com
State New
Headers
Series Proxy Execution: A generalized form of Priority Inheritance v6 |

Commit Message

John Stultz Nov. 6, 2023, 7:34 p.m. UTC 
  Add small helper for deactivating the selected task

Cc: Joel Fernandes <joelaf@google.com>
Cc: Qais Yousef <qyousef@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Zimuzo Ezeozue <zezeozue@google.com>
Cc: Youssef Esmat <youssefesmat@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: kernel-team@android.com
Signed-off-by: John Stultz <jstultz@google.com>
---
 kernel/sched/core.c | 43 +++++++++++++++++++++----------------------
 1 file changed, 21 insertions(+), 22 deletions(-)

Comments

kernel test robot Nov. 8, 2023, 2:51 a.m. UTC | #1 
Hi John,

kernel test robot noticed the following build warnings:

[auto build test WARNING on tip/locking/core]
[also build test WARNING on v6.6]
[cannot apply to tip/sched/core tip/master linus/master tip/auto-latest next-20231107]
[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/John-Stultz/sched-Unify-runtime-accounting-across-classes/20231107-033946
base:   tip/locking/core
patch link:    https://lore.kernel.org/r/20231106193524.866104-16-jstultz%40google.com
patch subject: [PATCH v6 15/20] sched: Add proxy deactivate helper
config: alpha-allyesconfig (https://download.01.org/0day-ci/archive/20231108/202311081028.yDLmCWgr-lkp@intel.com/config)
compiler: alpha-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231108/202311081028.yDLmCWgr-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/202311081028.yDLmCWgr-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> kernel/sched/core.c:6616:6: warning: no previous prototype for 'proxy_deactivate' [-Wmissing-prototypes]
    6616 | bool proxy_deactivate(struct rq *rq, struct task_struct *next)
         |      ^~~~~~~~~~~~~~~~


vim +/proxy_deactivate +6616 kernel/sched/core.c

  6615	
> 6616	bool proxy_deactivate(struct rq *rq, struct task_struct *next)
  6617	{
  6618		unsigned long state = READ_ONCE(next->__state);
  6619	
  6620		/* Don't deactivate if the state has been changed to TASK_RUNNING */
  6621		if (!state)
  6622			return false;
  6623		if (!try_to_deactivate_task(rq, next, state, true))
  6624			return false;
  6625		put_prev_task(rq, next);
  6626		rq_set_selected(rq, rq->idle);
  6627		resched_curr(rq);
  6628		return true;
  6629	}
  6630
John Stultz Nov. 18, 2023, 12:27 a.m. UTC | #2 
On Tue, Nov 7, 2023 at 6:52 PM kernel test robot <lkp@intel.com> wrote:
>
> kernel test robot noticed the following build warnings:
>
...
> >> kernel/sched/core.c:6616:6: warning: no previous prototype for 'proxy_deactivate' [-Wmissing-prototypes]
>     6616 | bool proxy_deactivate(struct rq *rq, struct task_struct *next)
>          |      ^~~~~~~~~~~~~~~~


Thank you! I've fixed this up for v7

thanks again
-john
diff mbox series

Patch

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5770656b898d..1b84d612332e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6612,6 +6612,22 @@  static bool try_to_deactivate_task(struct rq *rq, struct task_struct *p,
 }
 
 #ifdef CONFIG_PROXY_EXEC
+
+bool proxy_deactivate(struct rq *rq, struct task_struct *next)
+{
+	unsigned long state = READ_ONCE(next->__state);
+
+	/* Don't deactivate if the state has been changed to TASK_RUNNING */
+	if (!state)
+		return false;
+	if (!try_to_deactivate_task(rq, next, state, true))
+		return false;
+	put_prev_task(rq, next);
+	rq_set_selected(rq, rq->idle);
+	resched_curr(rq);
+	return true;
+}
+
 /*
  * Initial simple proxy that just returns the task if its waking
  * or deactivates the blocked task so we can pick something that
@@ -6620,10 +6636,9 @@  static bool try_to_deactivate_task(struct rq *rq, struct task_struct *p,
 static struct task_struct *
 proxy(struct rq *rq, struct task_struct *next, struct rq_flags *rf)
 {
+	struct task_struct *ret = NULL;
 	struct task_struct *p = next;
 	struct mutex *mutex;
-	unsigned long state;
-
 	mutex = p->blocked_on;
 	/* Something changed in the chain, pick_again */
 	if (!mutex)
@@ -6645,30 +6660,14 @@  proxy(struct rq *rq, struct task_struct *next, struct rq_flags *rf)
 		 */
 		raw_spin_unlock(&p->blocked_lock);
 		raw_spin_unlock(&mutex->wait_lock);
-		return NULL;
-	}
-
-	state = READ_ONCE(p->__state);
-	/* Don't deactivate if the state has been changed to TASK_RUNNING */
-	if (!state) {
-		raw_spin_unlock(&p->blocked_lock);
-		raw_spin_unlock(&mutex->wait_lock);
-		return p;
+		return ret;
 	}
 
-	try_to_deactivate_task(rq, next, state, true);
-
-	/*
-	 * If next is the selected task, then remove lingering
-	 * references to it from rq and sched_class structs after
-	 * dequeueing.
-	 */
-	put_prev_task(rq, next);
-	rq_set_selected(rq, rq->idle);
-	resched_curr(rq);
+	if (!proxy_deactivate(rq, next))
+		ret = p;
 	raw_spin_unlock(&p->blocked_lock);
 	raw_spin_unlock(&mutex->wait_lock);
-	return NULL;
+	return ret;
 }
 #else /* PROXY_EXEC */
 static struct task_struct *