linux-kernel - [PATCH 2/3] drm/scheduler: Don't call wait_event

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Message-ID: <1524583836-12130-3-git-send-email-andrey.grodzovsky@amd.com>
Date:   Tue, 24 Apr 2018 11:30:35 -0400
From:   Andrey Grodzovsky <andrey.grodzovsky@....com>
To:     <linux-kernel@...r.kernel.org>, <amd-gfx@...ts.freedesktop.org>
CC:     <Alexander.Deucher@....com>, <Christian.Koenig@....com>,
        <David.Panariti@....com>, <oleg@...hat.com>,
        <akpm@...ux-foundation.org>, <ebiederm@...ssion.com>,
        Andrey Grodzovsky <andrey.grodzovsky@....com>
Subject: [PATCH 2/3] drm/scheduler: Don't call wait_event_killable for signaled process.

Avoid calling wait_event_killable when you are possibly being called
from get_signal routine since in that case you end up in a deadlock
where you are alreay blocked in singla processing any trying to wait
on a new signal.

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@....com>
---
 drivers/gpu/drm/scheduler/gpu_scheduler.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/gpu_scheduler.c b/drivers/gpu/drm/scheduler/gpu_scheduler.c
index 088ff2b..09fd258 100644
--- a/drivers/gpu/drm/scheduler/gpu_scheduler.c
+++ b/drivers/gpu/drm/scheduler/gpu_scheduler.c
@@ -227,9 +227,10 @@ void drm_sched_entity_do_release(struct drm_gpu_scheduler *sched,
 		return;
 	/**
 	 * The client will not queue more IBs during this fini, consume existing
-	 * queued IBs or discard them on SIGKILL
+	 * queued IBs or discard them when in death signal state since
+	 * wait_event_killable can't receive signals in that state.
 	*/
-	if ((current->flags & PF_SIGNALED) && current->exit_code == SIGKILL)
+	if (current->flags & PF_SIGNALED)
 		entity->fini_status = -ERESTARTSYS;
 	else
 		entity->fini_status = wait_event_killable(sched->job_scheduled,
-- 
2.7.4