Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [RFC][PATCH 3/3] x86/entry, ORC: Teach objtool/unwind_orc about stack irq swizzles | Date | Fri, 08 May 2020 14:26:32 +0200 |
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Peter Zijlstra <peterz@infradead.org> writes:
> On Thu, May 07, 2020 at 11:24:49PM +0200, Thomas Gleixner wrote: >> But over our IRC conversation I came up with a 3rd variant: >> >> For most of the vectors the indirect call overhead is just noise, so >> we can run them through the ASM switcher, but for the resched IPI >> we can just use a separate direct call stub in ASM. > > Are we sure the rat-poison crap is noise for all the other system > vectors? I suppose it is for most since they'll do indirect calls > themselves anyway, right?
We have different categories:
1) Uninteresting
SPURIOUS_APIC_VECTOR, ERROR_APIC_VECTOR, THERMAL_APIC_VECTOR, THRESHOLD_APIC_VECTOR, REBOOT_VECTOR, DEFERRED_ERROR_VECTOR
2) Indirect call poisoned
LOCAL_TIMER_VECTOR X86_PLATFORM_IPI_VECTOR IRQ_WORK_VECTOR HYPERV_STIMER0_VECTOR HYPERVISOR_CALLBACK_VECTOR POSTED_INTERRUPT_WAKEUP_VECTOR. CALL_FUNCTION_VECTOR CALL_FUNCTION_SINGLE_VECTOR
3) Quick
RESCHEDULE_VECTOR
POSTED_INTR_VECTOR POSTED_INTR_NESTED_VECTOR
These two postit ones are weird because they are both empty and just increment different irq counts.
HYPERV_REENLIGHTENMENT_VECTOR
schedules delayed work, i,e. arms a timer which should be straight forward, but does it matter?
4) Others
UV_BAU_MESSAGE - The TLB flushes are probably more expensive than ratpoutine
Hmm?
Thanks,
tglx
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