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Arnaldo Carvalho de Melo authored
To pick up the changes in: b8d1d163 ("x86/apic: Don't disable x2APIC if locked") ca5b7c0d ("perf/x86/amd/lbr: Add LbrExtV2 branch record support") Addressing these tools/perf build warnings: diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h' That makes the beautification scripts to pick some new entries: $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > before $ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > after $ diff -u before after --- before 2022-10-14 18:06:34.294561729 -0300 +++ after 2022-10-14 18:06:41.285744044 -0300 @@ -264,6 +264,7 @@ [0xc0000102 - x86_64_specific_MSRs_offset] = "KERNEL_GS_BASE", [0xc0000103 - x86_64_specific_MSRs_offset] = "TSC_AUX", [0xc0000104 - x86_64_specific_MSRs_offset] = "AMD64_TSC_RATIO", + [0xc000010e - x86_64_specific_MSRs_offset] = "AMD64_LBR_SELECT", [0xc000010f - x86_64_specific_MSRs_offset] = "AMD_DBG_EXTN_CFG", [0xc0000300 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_STATUS", [0xc0000301 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_CTL", $ Now one can trace systemwide asking to see backtraces to where that MSR is being read/written, see this example with a previous update: # perf trace -e msr:*_msr/max-stack=32/ --filter="msr>=IA32_U_CET && msr<=IA32_INT_SSP_TAB" ^C# If we use -v (verbose mode) we can see what it does behind the scenes: # perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr>=IA32_U_CET && msr<=IA32_INT_SSP_TAB" Using CPUID AuthenticAMD-25-21-0 0x6a0 0x6a8 New filter for msr:read_msr: (msr>=0x6a0 && msr<=0x6a8) && (common_pid != 597499 && common_pid != 3313) 0x6a0 0x6a8 New filter for msr:write_msr: (msr>=0x6a0 && msr<=0x6a8) && (common_pid != 597499 && common_pid != 3313) mmap size 528384B ^C# Example with a frequent msr: # perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr==IA32_SPEC_CTRL" --max-events 2 Using CPUID AuthenticAMD-25-21-0 0x48 New filter for msr:read_msr: (msr==0x48) && (common_pid != 2612129 && common_pid != 3841) 0x48 New filter for msr:write_msr: (msr==0x48) && (common_pid != 2612129 && common_pid != 3841) mmap size 528384B Looking at the vmlinux_path (8 entries long) symsrc__init: build id mismatch for vmlinux. Using /proc/kcore for kernel data Using /proc/kallsyms for symbols 0.000 Timer/2525383 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6) do_trace_write_msr ([kernel.kallsyms]) do_trace_write_msr ([kernel.kallsyms]) __switch_to_xtra ([kernel.kallsyms]) __switch_to ([kernel.kallsyms]) __schedule ([kernel.kallsyms]) schedule ([kernel.kallsyms]) futex_wait_queue_me ([kernel.kallsyms]) futex_wait ([kernel.kallsyms]) do_futex ([kernel.kallsyms]) __x64_sys_futex ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __futex_abstimed_wait_common64 (/usr/lib64/libpthread-2.33.so) 0.030 :0/0 msr:write_msr(msr: IA32_SPEC_CTRL, val: 2) do_trace_write_msr ([kernel.kallsyms]) do_trace_write_msr ([kernel.kallsyms]) __switch_to_xtra ([kernel.kallsyms]) __switch_to ([kernel.kallsyms]) __schedule ([kernel.kallsyms]) schedule_idle ([kernel.kallsyms]) do_idle ([kernel.kallsyms]) cpu_startup_entry ([kernel.kallsyms]) secondary_startup_64_no_verify ([kernel.kallsyms]) # Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Daniel Sneddon <daniel.sneddon@linux.intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sandipan Das <sandipan.das@amd.com> Link: https://lore.kernel.org/lkml/Y0nQkz2TUJxwfXJd@kernel.orgSigned-off-by:
Arnaldo Carvalho de Melo <acme@redhat.com>
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