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Arnaldo Carvalho de Melo authored
The 'perf kvm' command set up things so that we can record, report, top, etc, but not 'script', so make 'perf script' be able to process samples by allowing to pass guest kallsyms, vmlinux, modules, etc, and if at least one of those is provided, set perf_guest to true so that guest samples get properly resolved. Testing it: # perf kvm --guest --guestkallsyms /wb/rhel6.kallsyms --guestmodules /wb/rhel6.modules record -e cycles:Gk ^C[ perf record: Woken up 7 times to write data ] [ perf record: Captured and wrote 3.602 MB perf.data.guest (10492 samples) ] # # perf evlist -i perf.data.guest cycles:Gk # perf evlist -v -i perf.data.guest cycles:Gk: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD, read_format: ID, disabled: 1, inherit: 1, exclude_user: 1, exclude_hv: 1, mmap: 1, comm: 1, freq: 1, task: 1, sample_id_all: 1, exclude_host: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1 # # perf kvm --guestkallsyms /wb/rhel6.kallsyms --guestmodules /wb/rhel6.modules report --stdio -s sym | head -30 # To display the perf.data header info, please use --header/--header-only options. # # # Total Lost Samples: 0 # # Samples: 10K of event 'cycles:Gk' # Event count (approx.): 2434201408 # # Overhead Symbol # ........ .............................................. # 11.93% [g] avtab_search_node 3.95% [g] sidtab_context_to_sid 2.41% [g] n_tty_write 2.20% [g] _spin_unlock_irqrestore 1.37% [g] _aesni_dec4 1.33% [g] kmem_cache_alloc 1.07% [g] native_write_cr0 0.99% [g] kfree 0.95% [g] _spin_lock 0.91% [g] __memset 0.87% [g] schedule 0.83% [g] _spin_lock_irqsave 0.76% [g] __kmalloc 0.67% [g] avc_has_perm_noaudit 0.66% [g] kmem_cache_free 0.65% [g] glue_xts_crypt_128bit 0.59% [g] __d_lookup 0.59% [g] __audit_syscall_exit 0.56% [g] __memcpy # Then, when trying to use perf script to generate a python script and then process the events after adding a python hook for non-tracepoint events: # perf script -i perf.data.guest -g python generated Python script: perf-script.py # vim perf-script.py # tail -2 perf-script.py def process_event(param_dict): print(param_dict["symbol"]) # # perf script -i perf.data.guest -s perf-script.py | head in trace_begin vmx_vmexit vmx_vmexit vmx_vmexit vmx_vmexit vmx_vmexit vmx_vmexit vmx_vmexit vmx_vmexit vmx_vmexit 231 # We'd see just the vmx_vmexit, i.e. the samples from the guest don't show up. After this patch: # perf script --guestkallsyms /wb/rhel6.kallsyms --guestmodules /wb/rhel6.modules -i perf.data.guest -s perf-script.py 2> /dev/null | head -30 in trace_begin apic_timer_interrupt apic_timer_interrupt apic_timer_interrupt apic_timer_interrupt apic_timer_interrupt save_args do_timer drain_array inode_permission avc_has_perm_noaudit run_timer_softirq apic_timer_interrupt apic_timer_interrupt apic_timer_interrupt apic_timer_interrupt apic_timer_interrupt kvm_guest_apic_eoi_write run_posix_cpu_timers _spin_lock handle_pte_fault rcu_irq_enter delay_tsc delay_tsc native_read_tsc apic_timer_interrupt sys_open internal_add_timer list_del rcu_exit_nohz # Jiri Olsa noticed we need to set 'perf_guest' to true if we want to process guest samples and I made it be set if one of the guest files settings get set via the command line options added in this patch, that match those present in the 'perf kvm' command. We probably want to have 'perf record', 'perf report' etc to notice that there are guest samples and do the right thing, which is to look for files with some suffix that make it be associated with the guest used to collect the samples, i.e. if a vmlinux file is passed, we can get the build-id from it, if not some other identifier or simply looking for "kallsyms.guest", for instance, in the current directory. Reported-by:Mariano Pache <npache@redhat.com> Tested-by:
Arnaldo Carvalho de Melo <acme@redhat.com>
15a108af
