diff options
Diffstat (limited to 'sched-Remove-lockdep-check-in-sched_move_task.patch')
-rw-r--r-- | sched-Remove-lockdep-check-in-sched_move_task.patch | 49 |
1 files changed, 0 insertions, 49 deletions
diff --git a/sched-Remove-lockdep-check-in-sched_move_task.patch b/sched-Remove-lockdep-check-in-sched_move_task.patch deleted file mode 100644 index b740be10d..000000000 --- a/sched-Remove-lockdep-check-in-sched_move_task.patch +++ /dev/null @@ -1,49 +0,0 @@ -From: Kirill Tkhai <ktkhai@parallels.com> -Date: Tue, 28 Oct 2014 08:24:34 +0300 -Subject: [PATCH] sched: Remove lockdep check in sched_move_task() - -sched_move_task() is the only interface to change sched_task_group: -cpu_cgrp_subsys methods and autogroup_move_group() use it. - -Everything is synchronized by task_rq_lock(), so cpu_cgroup_attach() -is ordered with other users of sched_move_task(). This means we do no -need RCU here: if we've dereferenced a tg here, the .attach method -hasn't been called for it yet. - -Thus, we should pass "true" to task_css_check() to silence lockdep -warnings. - -Fixes: eeb61e53ea19 ("sched: Fix race between task_group and sched_task_group") -Reported-by: Oleg Nesterov <oleg@redhat.com> -Reported-by: Fengguang Wu <fengguang.wu@intel.com> -Signed-off-by: Kirill Tkhai <ktkhai@parallels.com> -Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> -Cc: Linus Torvalds <torvalds@linux-foundation.org> -Link: http://lkml.kernel.org/r/1414473874.8574.2.camel@tkhai -Signed-off-by: Ingo Molnar <mingo@kernel.org> ---- - kernel/sched/core.c | 8 ++++++-- - 1 file changed, 6 insertions(+), 2 deletions(-) - -diff --git a/kernel/sched/core.c b/kernel/sched/core.c -index 240157c13ddc..6841fb46eb07 100644 ---- a/kernel/sched/core.c -+++ b/kernel/sched/core.c -@@ -7444,8 +7444,12 @@ void sched_move_task(struct task_struct *tsk) - if (unlikely(running)) - put_prev_task(rq, tsk); - -- tg = container_of(task_css_check(tsk, cpu_cgrp_id, -- lockdep_is_held(&tsk->sighand->siglock)), -+ /* -+ * All callers are synchronized by task_rq_lock(); we do not use RCU -+ * which is pointless here. Thus, we pass "true" to task_css_check() -+ * to prevent lockdep warnings. -+ */ -+ tg = container_of(task_css_check(tsk, cpu_cgrp_id, true), - struct task_group, css); - tg = autogroup_task_group(tsk, tg); - tsk->sched_task_group = tg; --- -1.9.3 - |