• Arnaldo Carvalho de Melo's avatar
    perf tools: Separate accounting of contexts and real addresses in a stack trace · a29d5c9b
    Arnaldo Carvalho de Melo authored
    The perf_sample->ip_callchain->nr value includes all the entries in the
    ip_callchain->ip[] array, real addresses and PERF_CONTEXT_{KERNEL,USER,etc},
    while what the user expects is that what is in the kernel.perf_event_max_stack
    sysctl or in the upcoming per event perf_event_attr.sample_max_stack knob be
    honoured in terms of IP addresses in the stack trace.
    
    So match the kernel support and validate chain->nr taking into account
    both kernel.perf_event_max_stack and kernel.perf_event_max_contexts_per_stack.
    
    Cc: Adrian Hunter <adrian.hunter@intel.com>
    Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
    Cc: Alexei Starovoitov <ast@kernel.org>
    Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
    Cc: David Ahern <dsahern@gmail.com>
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
    Cc: He Kuang <hekuang@huawei.com>
    Cc: Jiri Olsa <jolsa@redhat.com>
    Cc: Masami Hiramatsu <mhiramat@kernel.org>
    Cc: Milian Wolff <milian.wolff@kdab.com>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Stephane Eranian <eranian@google.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Vince Weaver <vincent.weaver@maine.edu>
    Cc: Wang Nan <wangnan0@huawei.com>
    Cc: Zefan Li <lizefan@huawei.com>
    Link: http://lkml.kernel.org/n/tip-mgx0jpzfdq4uq4abfa40byu0@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    a29d5c9b
machine.c 51.3 KB