From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-rt-users@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de,
Steven Rostedt <rostedt@goodmis.org>
Subject: [PATCH RT] arm: lazy preempt: correct resched condition
Date: Tue, 24 May 2016 13:30:36 +0200 [thread overview]
Message-ID: <20160524113036.GA27094@linutronix.de> (raw)
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
reply other threads:[~2016-05-24 11:30 UTC|newest]
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