From: Sebastian Andrzej Siewior Date: Tue, 24 May 2016 12:56:38 +0200 Subject: [PATCH] arm: lazy preempt: correct resched condition Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.6/older/patches-4.6.2-rt5.tar.xz 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 --- 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: