Messages in this thread Patch in this message | | | From | Arnaldo Carvalho de Melo <> | Subject | [PATCH 1/3] perf tools: Fixup exit path when not able to open events | Date | Tue, 29 Mar 2011 23:35:30 -0300 |
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From: Arnaldo Carvalho de Melo <acme@redhat.com>
We have to deal with the TUI mode in perf top, so that we don't end up with a garbled screen when, say, a non root user on a machine with a paranoid setting (the default) tries to use 'perf top'.
Introduce a ui__warning_paranoid() routine shared by top and record that tells the user the valid values for /proc/sys/kernel/perf_event_paranoid.
Cc: David Ahern <daahern@cisco.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/builtin-record.c | 9 ++++----- tools/perf/builtin-top.c | 38 ++++++++++++++++++++++++-------------- tools/perf/util/debug.c | 10 ++++++++++ tools/perf/util/debug.h | 1 + 4 files changed, 39 insertions(+), 19 deletions(-)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 6febcc1..623695e 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -275,11 +275,10 @@ try_again: !no_inherit) < 0) { int err = errno; - if (err == EPERM || err == EACCES) - die("Permission error - are you root?\n" - "\t Consider tweaking" - " /proc/sys/kernel/perf_event_paranoid.\n"); - else if (err == ENODEV && cpu_list) { + if (err == EPERM || err == EACCES) { + ui__warning_paranoid(); + exit(EXIT_FAILURE); + } else if (err == ENODEV && cpu_list) { die("No such device - did you specify" " an out-of-range profile CPU?\n"); } else if (err == EINVAL && sample_id_all_avail) { diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 676b4fb..935fc4f 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -850,10 +850,10 @@ try_again: top.evlist->threads, group, inherit) < 0) { int err = errno; - if (err == EPERM || err == EACCES) - die("Permission error - are you root?\n" - "\t Consider tweaking" - " /proc/sys/kernel/perf_event_paranoid.\n"); + if (err == EPERM || err == EACCES) { + ui__warning_paranoid(); + goto out_err; + } /* * If it's cycles then fall back to hrtimer * based cpu-clock-tick sw counter, which @@ -861,25 +861,35 @@ try_again: */ if (attr->type == PERF_TYPE_HARDWARE && attr->config == PERF_COUNT_HW_CPU_CYCLES) { - if (verbose) - warning(" ... trying to fall back to cpu-clock-ticks\n"); + ui__warning("Cycles event not supported,\n" + "trying to fall back to cpu-clock-ticks\n"); attr->type = PERF_TYPE_SOFTWARE; attr->config = PERF_COUNT_SW_CPU_CLOCK; goto try_again; } - printf("\n"); - error("sys_perf_event_open() syscall returned with %d " - "(%s). /bin/dmesg may provide additional information.\n", - err, strerror(err)); - die("No CONFIG_PERF_EVENTS=y kernel support configured?\n"); - exit(-1); + + ui__warning("The sys_perf_event_open() syscall " + "returned with %d (%s). /bin/dmesg " + "may provide additional information.\n" + "No CONFIG_PERF_EVENTS=y kernel support " + "configured?\n", err, strerror(err)); + goto out_err; } } - if (perf_evlist__mmap(evlist, mmap_pages, false) < 0) - die("failed to mmap with %d (%s)\n", errno, strerror(errno)); + if (perf_evlist__mmap(evlist, mmap_pages, false) < 0) { + ui__warning("Failed to mmap with %d (%s)\n", + errno, strerror(errno)); + goto out_err; + } + + return; + +out_err: + exit_browser(0); + exit(0); } static int __cmd_top(void) diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c index d4536a9..155749d 100644 --- a/tools/perf/util/debug.c +++ b/tools/perf/util/debug.c @@ -57,6 +57,16 @@ void ui__warning(const char *format, ...) } #endif +void ui__warning_paranoid(void) +{ + ui__warning("Permission error - are you root?\n" + "Consider tweaking /proc/sys/kernel/perf_event_paranoid:\n" + " -1 - Not paranoid at all\n" + " 0 - Disallow raw tracepoint access for unpriv\n" + " 1 - Disallow cpu events for unpriv\n" + " 2 - Disallow kernel profiling for unpriv\n"); +} + void trace_event(union perf_event *event) { unsigned char *raw_event = (void *)event; diff --git a/tools/perf/util/debug.h b/tools/perf/util/debug.h index 93516cf..fd53db4 100644 --- a/tools/perf/util/debug.h +++ b/tools/perf/util/debug.h @@ -36,5 +36,6 @@ int ui_helpline__show_help(const char *format, va_list ap); #endif void ui__warning(const char *format, ...) __attribute__((format(printf, 1, 2))); +void ui__warning_paranoid(void); #endif /* __PERF_DEBUG_H */ -- 1.6.2.5
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