Messages in this thread | | | From | Marco Elver <> | Date | Fri, 21 Oct 2022 00:37:26 -0700 | Subject | Re: [PATCH v7 18/43] instrumented.h: add KMSAN support |
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On Thu, 20 Oct 2022 at 23:39, youling 257 <youling257@gmail.com> wrote: > > PerfTop: 8253 irqs/sec kernel:75.3% exact: 100.0% lost: 0/0 drop: > 0/17899 [4000Hz cycles], (all, 8 CPUs) > --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- > > 14.87% [kernel] [k] 0xffffffff941d1f37 > 6.71% [kernel] [k] 0xffffffff942016cf > > what is 0xffffffff941d1f37?
You need to build with debug symbols: CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y
Then it'll show function names.
> 2022-10-21 14:16 GMT+08:00, Marco Elver <elver@google.com>: > > On Thu, 20 Oct 2022 at 22:55, youling 257 <youling257@gmail.com> wrote: > >> > >> How to use perf tool? > > > > The simplest would be to try just "perf top" - and see which kernel > > functions consume most CPU cycles. I would suggest you compare both > > kernels, and see if you can spot a function which uses more cycles% in > > the problematic kernel. > >
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