diff options
Diffstat (limited to 'lib/tools/doc/src/fprof.xml')
| -rw-r--r-- | lib/tools/doc/src/fprof.xml | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/lib/tools/doc/src/fprof.xml b/lib/tools/doc/src/fprof.xml index 4c9e48045e..72624bd33b 100644 --- a/lib/tools/doc/src/fprof.xml +++ b/lib/tools/doc/src/fprof.xml @@ -328,10 +328,16 @@ purposes. This option is only allowed with the <c>start</c> option.</item> <tag><c>cpu_time</c>| <c>{cpu_time, bool()}</c></tag> - <item>The options <c>cpu_time</c> or <c>{cpu_time, true></c> + <item>The options <c>cpu_time</c> or <c>{cpu_time, true}</c> makes the timestamps in the trace be in CPU time instead of wallclock time which is the default. This option is - only allowed with the <c>start</c> option.</item> + only allowed with the <c>start</c> option. + <warning><p>Getting correct values out of cpu_time can be difficult. + The best way to get correct values is to run using a single + scheduler and bind that scheduler to a specific CPU, + i.e. <c>erl +S 1 +sbt db</c>.</p> + </warning> + </item> <tag><c>{procs, PidSpec}</c>| <c>{procs, [PidSpec]}</c></tag> <item>Specifies which processes that shall be traced. If this option is not given, the calling process is |