| Message ID | 20190311224752.8337-13-valentin.schneider@arm.com |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
| Series | entry: preempt_schedule_irq() callers scrub | expand |
From: Valentin Schneider <valentin.schneider@arm.com> Date: Mon, 11 Mar 2019 22:47:50 +0000 > Since the enabling and disabling of IRQs within preempt_schedule_irq() > is contained in a need_resched() loop, we don't need the outer arch > code loop. > > We seem to be looping back somewhere much higher than the usual > preempt/need_resched checks, but AFAICT we would just branch to > 'rtrap_no_irq_enable' and then back to 'to_kernel', which is > a need_resched() loop with a few extra steps. > > Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> > Cc: "David S. Miller" <davem@davemloft.net> > Cc: sparclinux@vger.kernel.org > --- > arch/sparc/kernel/rtrap_64.S | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/arch/sparc/kernel/rtrap_64.S b/arch/sparc/kernel/rtrap_64.S > index 29aa34f11720..57fb75686957 100644 > --- a/arch/sparc/kernel/rtrap_64.S > +++ b/arch/sparc/kernel/rtrap_64.S > @@ -322,7 +322,6 @@ to_kernel: > nop > call preempt_schedule_irq > nop > - ba,pt %xcc, rtrap > #endif > kern_fpucheck: ldub [%g6 + TI_FPDEPTH], %l5 > brz,pt %l5, rt_continue > -- > 2.20.1 > We must re-evaluate the %tstate value stored in ptregs, you cannot make this change.
Hi, On 11/03/2019 23:13, David Miller wrote: [...] > > We must re-evaluate the %tstate value stored in ptregs, you cannot > make this change. > That's the one I was the less sure about, thanks for clearing it up and sorry for the noise.
diff --git a/arch/sparc/kernel/rtrap_64.S b/arch/sparc/kernel/rtrap_64.S index 29aa34f11720..57fb75686957 100644 --- a/arch/sparc/kernel/rtrap_64.S +++ b/arch/sparc/kernel/rtrap_64.S @@ -322,7 +322,6 @@ to_kernel: nop call preempt_schedule_irq nop - ba,pt %xcc, rtrap #endif kern_fpucheck: ldub [%g6 + TI_FPDEPTH], %l5 brz,pt %l5, rt_continue
Since the enabling and disabling of IRQs within preempt_schedule_irq() is contained in a need_resched() loop, we don't need the outer arch code loop. We seem to be looping back somewhere much higher than the usual preempt/need_resched checks, but AFAICT we would just branch to 'rtrap_no_irq_enable' and then back to 'to_kernel', which is a need_resched() loop with a few extra steps. Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: sparclinux@vger.kernel.org --- arch/sparc/kernel/rtrap_64.S | 1 - 1 file changed, 1 deletion(-)