diff options
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 0d12dbde8399..6cf8fd03b028 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3813,6 +3813,9 @@ static const char readme_msg[] = #ifdef CONFIG_TRACER_SNAPSHOT "\t\t snapshot\n" #endif +#ifdef CONFIG_HIST_TRIGGERS + "\t\t hist (see below)\n" +#endif "\t example: echo traceoff > events/block/block_unplug/trigger\n" "\t echo traceoff:3 > events/block/block_unplug/trigger\n" "\t echo 'enable_event:kmem:kmalloc:3 if nr_rq > 1' > \\\n" @@ -3828,6 +3831,20 @@ static const char readme_msg[] = "\t To remove a trigger with a count:\n" "\t echo '!<trigger>:0 > <system>/<event>/trigger\n" "\t Filters can be ignored when removing a trigger.\n" +#ifdef CONFIG_HIST_TRIGGERS + " hist trigger\t- If set, event hits are aggregated into a hash table\n" + "\t Format: hist:keys=<field1>\n" + "\t [:size=#entries]\n" + "\t [if <filter>]\n\n" + "\t When a matching event is hit, an entry is added to a hash\n" + "\t table using the key named, and the value of a sum called\n" + "\t 'hitcount' is incremented. Keys correspond to fields in the\n" + "\t event's format description. Keys can be any field. The\n" + "\t 'size' parameter can be used to specify more or fewer than\n" + "\t the default 2048 entries for the hashtable size.\n\n" + "\t Reading the 'hist' file for the event will dump the hash\n" + "\t table in its entirety to stdout." +#endif ; static ssize_t |