From 895d97663c83f8ed7a3386e912009155524fe7dd Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 25 May 2012 14:49:51 -0300 Subject: 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 Cc: Frederic Weisbecker Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-w1neie2dqli89we1bzwkf4id@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 6031dce..d4a5f9b 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -953,7 +953,7 @@ try_again: attr->config = PERF_COUNT_SW_CPU_CLOCK; if (counter->name) { free(counter->name); - counter->name = strdup(event_name(counter)); + counter->name = NULL; } goto try_again; } -- cgit v0.10.2