• Arnaldo Carvalho de Melo's avatar
    perf core: Per event callchain limit · 97c79a38
    Arnaldo Carvalho de Melo authored
    Additionally to being able to control the system wide maximum depth via
    /proc/sys/kernel/perf_event_max_stack, now we are able to ask for
    different depths per event, using perf_event_attr.sample_max_stack for
    that.
    
    This uses an u16 hole at the end of perf_event_attr, that, when
    perf_event_attr.sample_type has the PERF_SAMPLE_CALLCHAIN, if
    sample_max_stack is zero, means use perf_event_max_stack, otherwise
    it'll be bounds checked under callchain_mutex.
    
    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: Linus Torvalds <torvalds@linux-foundation.org>
    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-kolmn1yo40p7jhswxwrc7rrd@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    97c79a38
stackmap.c 7.39 KB