| From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| Date: Tue, 24 May 2016 12:56:38 +0200 |
| Subject: [PATCH] arm: lazy preempt: correct resched condition |
| |
| 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. |
| |
| Cc: stable-rt@vger.kernel.org |
| Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| --- |
| arch/arm/kernel/entry-armv.S | 6 +++++- |
| 1 file changed, 5 insertions(+), 1 deletion(-) |
| |
| --- 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: |