CONFIG_DEBUG_INFO=y CONFIG_AS_HAS_NON_CONST_LEB128=y # CONFIG_DEBUG_INFO_NONE is not set CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y # CONFIG_DEBUG_INFO_DWARF4 is not set # CONFIG_DEBUG_INFO_DWARF5 is not set # CONFIG_DEBUG_INFO_REDUCED is not set # CONFIG_DEBUG_INFO_COMPRESSED is not set # CONFIG_DEBUG_INFO_SPLIT is not set # CONFIG_DEBUG_INFO_BTF is not set # CONFIG_GDB_SCRIPTS is not set perf top still no function name. 12.90% [kernel] [k] 0xffffffff833dfa64 3.78% [kernel] [k] 0xffffffff8285b439 3.61% [kernel] [k] 0xffffffff83370254 2.32% [kernel] [k] 0xffffffff8337025b 1.88% bluetooth.default.so [.] 0x000000000000d09d 2022-10-21 15:37 GMT+08:00, Marco Elver <elver@xxxxxxxxxx>: > On Thu, 20 Oct 2022 at 23:39, youling 257 <youling257@xxxxxxxxx> 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@xxxxxxxxxx>: >> > On Thu, 20 Oct 2022 at 22:55, youling 257 <youling257@xxxxxxxxx> 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. >> > >