H A D | builtin-top.c | 895d9766 Fri May 25 12:49:51 CDT 2012 Arnaldo Carvalho de Melo <acme@redhat.com> perf top: Fix counter name fixup when fallbacking to cpu-clock
In 40491eaa "perf top: Update event name when falling back to cpu-clock" we freed counter->name but didn't reset it to NULL, then when setting it to the result of event_name(), event_name() would use the cached value, which by now was overwritten and thus we got garbage or a zero lenght string.
Fix it by just freeing and setting counter->name to NULL, this way event_name() when called afterwards, will find the right counter name and cache it again.
Found while trying 'cycles:pp' on a machine were :pp couldn't be honoured. Probably the best fallback here is to tell the user that that level of precision is not available on the PMU and then go removing 'p', levels of precision till we get to play 'cycles' and if even that fails, _then_ get to 'cpu-clock'.
But that is the matter for another patch, this one just needs to fix the caching issue, which in the end will show 'cpu-clock' when tools ask for the event name being used, which clarifies things for the user, that will see that 'cycles:pp' or whatever not support event is not being used, some sort of fallback happened.
Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-w1neie2dqli89we1bzwkf4id@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> 40491eaa Tue May 08 11:49:49 CDT 2012 David Ahern <dsahern@gmail.com> perf top: Update event name when falling back to cpu-clock
The 'perf top' command falls back to cpu-clock if the H/W cycles event is not supported, but the event name is not updated leading to a misleading header:
PerfTop: 8 irqs/sec kernel:75.0% exact: 0.0% [1000Hz cycles], ...
Update the event name when the event type is changed so that the header displays correctly:
PerfTop: 794 irqs/sec kernel:100.0% exact: 0.0% [1000Hz cpu-clock], ...
Signed-off-by: David Ahern <dsahern@gmail.com> Link: http://lkml.kernel.org/r/1336495789-58420-1-git-send-email-dsahern@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> 895d9766 Fri May 25 12:49:51 CDT 2012 Arnaldo Carvalho de Melo <acme@redhat.com> perf top: Fix counter name fixup when fallbacking to cpu-clock In 40491eaa "perf top: Update event name when falling back to cpu-clock" we freed counter->name but didn't reset it to NULL, then when setting it to the result of event_name(), event_name() would use the cached value, which by now was overwritten and thus we got garbage or a zero lenght string. Fix it by just freeing and setting counter->name to NULL, this way event_name() when called afterwards, will find the right counter name and cache it again. Found while trying 'cycles:pp' on a machine were :pp couldn't be honoured. Probably the best fallback here is to tell the user that that level of precision is not available on the PMU and then go removing 'p', levels of precision till we get to play 'cycles' and if even that fails, _then_ get to 'cpu-clock'. But that is the matter for another patch, this one just needs to fix the caching issue, which in the end will show 'cpu-clock' when tools ask for the event name being used, which clarifies things for the user, that will see that 'cycles:pp' or whatever not support event is not being used, some sort of fallback happened. Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-w1neie2dqli89we1bzwkf4id@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> 40491eaa Tue May 08 11:49:49 CDT 2012 David Ahern <dsahern@gmail.com> perf top: Update event name when falling back to cpu-clock The 'perf top' command falls back to cpu-clock if the H/W cycles event is not supported, but the event name is not updated leading to a misleading header: PerfTop: 8 irqs/sec kernel:75.0% exact: 0.0% [1000Hz cycles], ... Update the event name when the event type is changed so that the header displays correctly: PerfTop: 794 irqs/sec kernel:100.0% exact: 0.0% [1000Hz cpu-clock], ... Signed-off-by: David Ahern <dsahern@gmail.com> Link: http://lkml.kernel.org/r/1336495789-58420-1-git-send-email-dsahern@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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