Hi Thomas,
At 06/04/2018 11:33 PM, Thomas Gleixner wrote:
apic_ack_edge() is explicitely for handling interrupt affinity cleanup when interrupt remapping is not available or disable.
Remapped interrupts and also some of the platform specific special interrupts, e.g. UV, invoke ack_APIC_irq() directly.
To address the issue of failing an affinity update with -EBUSY the delayed affinity mechanism can be reused, but ack_APIC_irq() does not handle that. Adding this to ack_APIC_irq() is not possible, because that function is also used for exceptions and directly handled interrupts like IPIs.
Create a new function, which just contains the conditional invocation of irq_move_irq() and the final ack_APIC_irq(). Making the invocation of irq_move_irq() conditional avoids the out of line call if the pending bit is not set.
Reuse the new function in apic_ack_edge().
Preparatory change for the real fix
Fixes: dccfe3147b42 ("x86/vector: Simplify vector move cleanup") Signed-off-by: Thomas Gleixnertglx@linutronix.de Cc:stable@vger.kernel.org
arch/x86/include/asm/apic.h | 2 ++ arch/x86/kernel/apic/vector.c | 10 ++++++++-- 2 files changed, 10 insertions(+), 2 deletions(-)
--- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -436,6 +436,8 @@ static inline void apic_set_eoi_write(vo #endif /* CONFIG_X86_LOCAL_APIC */ +extern void apic_ack_irq(struct irq_data *data);
- static inline void ack_APIC_irq(void) { /*
--- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -809,11 +809,17 @@ static int apic_retrigger_irq(struct irq return 1; } +void apic_ack_irq(struct irq_data *irqd) +{
- if (unlikely(irqd_is_setaffinity_pending(irqd)))
Affinity pending is also judged in
irq_move_irq(irqd);
If we can remove the if(...) statement here
Thanks, dou
- ack_APIC_irq();
+}
- void apic_ack_edge(struct irq_data *irqd) { irq_complete_move(irqd_cfg(irqd));
- irq_move_irq(irqd);
- ack_APIC_irq();
- apic_ack_irq(irqd); }
static struct irq_chip lapic_controller = {
On Tue, 5 Jun 2018, Dou Liyang wrote:
+{
- if (unlikely(irqd_is_setaffinity_pending(irqd)))
Affinity pending is also judged in
irq_move_irq(irqd);If we can remove the if(...) statement here
That requires to fix all call sites in ia64 and that's why I didn't. But we can make irq_move_irq() an inline function and have the check in the inline.
Thanks,
tglx
Hi Thomas,
At 06/05/2018 07:41 PM, Thomas Gleixner wrote:
On Tue, 5 Jun 2018, Dou Liyang wrote:
+{
- if (unlikely(irqd_is_setaffinity_pending(irqd)))
Affinity pending is also judged in
irq_move_irq(irqd);If we can remove the if(...) statement here
That requires to fix all call sites in ia64 and that's why I didn't. But
I didn't express clearly, I meant remove the if(...) statement from apic_ack_irq(), it doesn't require to fix the call sites in ia64.
+void apic_ack_irq(struct irq_data *irqd) +{ + irq_move_irq(irqd); + ack_APIC_irq(); +}
BTW, If apic_ack_irq() can accept _any_ irq_data when hierarchical irqdomains are enabled[1]? If it is true, If there is a situation in the original code that we should avoid:
If the top-level irq_data has the IRQD_SETAFFINITY_PENDING state, but non-top-level irq_data state not, when using non-top-level irq_data in apic_ack_irq(), we may skip the irq_move_irq() which we should call.
[1] commit 77ed42f18edd("genirq: Prevent crash in irq_move_irq()")
we can make irq_move_irq() an inline function and have the check in the inline.
I don't know why do we need to make irq_move_irq() an inline function.
And, yes, irq_move_irq() has already had the check
... if (likely(!irqd_is_setaffinity_pending(idata))) return; ...
Thanks, dou
On Wed, 6 Jun 2018, Dou Liyang wrote:
Hi Thomas,
At 06/05/2018 07:41 PM, Thomas Gleixner wrote:
On Tue, 5 Jun 2018, Dou Liyang wrote:
+{
- if (unlikely(irqd_is_setaffinity_pending(irqd)))
Affinity pending is also judged in
irq_move_irq(irqd);If we can remove the if(...) statement here
That requires to fix all call sites in ia64 and that's why I didn't. But
I didn't express clearly, I meant remove the if(...) statement from apic_ack_irq(), it doesn't require to fix the call sites in ia64.
I put the check there on purpose as I explained in the changelog:
Making the invocation of irq_move_irq() conditional avoids the out of line call if the pending bit is not set.
Thanks,
tglx
Hi Thomas,
At 06/06/2018 04:04 PM, Thomas Gleixner wrote:
On Wed, 6 Jun 2018, Dou Liyang wrote:
Hi Thomas,
At 06/05/2018 07:41 PM, Thomas Gleixner wrote:
On Tue, 5 Jun 2018, Dou Liyang wrote:
+{
- if (unlikely(irqd_is_setaffinity_pending(irqd)))
Affinity pending is also judged in
irq_move_irq(irqd);If we can remove the if(...) statement here
That requires to fix all call sites in ia64 and that's why I didn't. But
I didn't express clearly, I meant remove the if(...) statement from apic_ack_irq(), it doesn't require to fix the call sites in ia64.
I put the check there on purpose as I explained in the changelog:
Making the invocation of irq_move_irq() conditional avoids the out of line call if the pending bit is not set.
I completely understand now, thank you so much. :-)
Thanks, dou
Thanks,
tglx
linux-stable-mirror@lists.linaro.org
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Dou Liyang -
Thomas Gleixner