Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: x86/smp: adding new trace points | Date | Wed, 13 May 2020 14:24:40 +0200 |
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Wojciech Kudla <wk.kernel@gmail.com> writes: > I was trying to trace some IPIs (remote tlb shootdowns in this case) and noticed that: > > 1) irq_vectors:x86_platform_ipi_entry and irq_vectors:x86_platform_ipi_exit are not hit at all for my case. The backtrace on the receiving CPU: > > 0xffffffff81079535 flush_tlb_func_common.constprop.10+0x105/0x220 [kernel] > 0xffffffff81079681 flush_tlb_func_remote+0x31/0x40 [kernel] > 0xffffffff8111f76c flush_smp_call_function_queue+0x4c/0xf0 [kernel] > 0xffffffff81120253 generic_smp_call_function_single_interrupt+0x13/0x30 [kernel] > 0xffffffff81a030c6 smp_call_function_single_interrupt+0x36/0xd0 [kernel] > 0xffffffff81a02679 call_function_single_interrupt+0xa9/0xb0 [kernel] > > I would expect that we would hit those trace point somewhere around > call_function_single_interrupt()
Why would the SMP call function single interrupt go through the PLATFORM_IPI_VECTOR? It goes as the name says through the CALL_FUNCTION_SINGLE_VECTOR.
Thanks,
tglx
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