sched/core: Add clearing of ->dl_server in put_prev_task_balance()

commit c245910049d04fbfa85bb2f5acd591c24e9907c7 upstream.

Paths using put_prev_task_balance() need to do a pick shortly
after. Make sure they also clear the ->dl_server on prev as a
part of that.

Fixes: 63ba8422f876 ("sched/deadline: Introduce deadline servers")
Signed-off-by: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/d184d554434bedbad0581cb34656582d78655150.1716811044.git.bristot@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 3e84a3b7b7bb9bcad355a53ce482f185ec35af66..875fc6e720757f2d329fc81f9e3fc1f2c3ecff79 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6005,6 +6005,14 @@ static void put_prev_task_balance(struct rq *rq, struct task_struct *prev,
 #endif
 
        put_prev_task(rq, prev);
+
+       /*
+        * We've updated @prev and no longer need the server link, clear it.
+        * Must be done before ->pick_next_task() because that can (re)set
+        * ->dl_server.
+        */
+       if (prev->dl_server)
+               prev->dl_server = NULL;
 }
 
 /*
@@ -6048,14 +6056,6 @@ __pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 restart:
        put_prev_task_balance(rq, prev, rf);
 
-       /*
-        * We've updated @prev and no longer need the server link, clear it.
-        * Must be done before ->pick_next_task() because that can (re)set
-        * ->dl_server.
-        */
-       if (prev->dl_server)
-               prev->dl_server = NULL;
-
        for_each_class(class) {
                p = class->pick_next_task(rq);
                if (p)