* [PATCH RT] arm: lazy preempt: correct resched condition
@ 2016-05-24 11:30 Sebastian Andrzej Siewior
0 siblings, 0 replies; only message in thread
From: Sebastian Andrzej Siewior @ 2016-05-24 11:30 UTC (permalink / raw)
To: linux-rt-users; +Cc: linux-kernel, tglx, Steven Rostedt
If we get out of preempt_schedule_irq() then we check for NEED_RESCHED
and call the former function again if set because the preemption counter
has be zero at this point.
However the counter for lazy-preempt might not be zero therefore we have
to check the counter before looking at the need_resched_lazy flag.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
arch/arm/kernel/entry-armv.S | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index d66b1aef2083..d044cea59f54 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -244,7 +244,11 @@ ENDPROC(__irq_svc)
bne 1b
tst r0, #_TIF_NEED_RESCHED_LAZY
reteq r8 @ go again
- b 1b
+ ldr r0, [tsk, #TI_PREEMPT_LAZY] @ get preempt lazy count
+ teq r0, #0 @ if preempt lazy count != 0
+ beq 1b
+ ret r8 @ go again
+
#endif
__und_fault:
--
2.8.1
^ permalink raw reply related [flat|nested] only message in thread
only message in thread, other threads:[~2016-05-24 11:30 UTC | newest]
Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-05-24 11:30 [PATCH RT] arm: lazy preempt: correct resched condition Sebastian Andrzej Siewior
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).