| Message ID | 20211027205919.1648553-2-kaleshsingh@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | tracing/kselftest: histogram trigger expression tests | expand |
On Wed, 27 Oct 2021 13:59:08 -0700 Kalesh Singh <kaleshsingh@google.com> wrote: > Update the tracefs README to describe how hist trigger variables > can be created. > > Signed-off-by: Kalesh Singh <kaleshsingh@google.com> This looks good to me. Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Thank you! > --- > kernel/trace/trace.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index bc677cd64224..c41b3786401d 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -5628,6 +5628,7 @@ static const char readme_msg[] = > #ifdef CONFIG_HIST_TRIGGERS > " hist trigger\t- If set, event hits are aggregated into a hash table\n" > "\t Format: hist:keys=<field1[,field2,...]>\n" > + "\t [:<var1>=<field|var_ref|numeric_literal>[,<var2>=...]]\n" > "\t [:values=<field1[,field2,...]>]\n" > "\t [:sort=<field1[,field2,...]>]\n" > "\t [:size=#entries]\n" > @@ -5639,6 +5640,16 @@ static const char readme_msg[] = > "\t common_timestamp - to record current timestamp\n" > "\t common_cpu - to record the CPU the event happened on\n" > "\n" > + "\t A hist trigger variable can be:\n" > + "\t - a reference to a field e.g. x=current_timestamp,\n" > + "\t - a reference to another variable e.g. y=$x,\n" > + "\t - a numeric literal: e.g. ms_per_sec=1000,\n" > + "\t - an arithmetic expression: e.g. time_secs=current_timestamp/1000\n" > + "\n" > + "\t hist trigger aritmethic expressions support addition(+), subtraction(-),\n" > + "\t multiplication(*) and division(/) operators. An operand can be either a\n" > + "\t variable reference, field or numeric literal.\n" > + "\n" > "\t When a matching event is hit, an entry is added to a hash\n" > "\t table using the key(s) and value(s) named, and the value of a\n" > "\t sum called 'hitcount' is incremented. Keys and values\n" > -- > 2.33.0.1079.g6e70778dc9-goog >
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index bc677cd64224..c41b3786401d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5628,6 +5628,7 @@ static const char readme_msg[] = #ifdef CONFIG_HIST_TRIGGERS " hist trigger\t- If set, event hits are aggregated into a hash table\n" "\t Format: hist:keys=<field1[,field2,...]>\n" + "\t [:<var1>=<field|var_ref|numeric_literal>[,<var2>=...]]\n" "\t [:values=<field1[,field2,...]>]\n" "\t [:sort=<field1[,field2,...]>]\n" "\t [:size=#entries]\n" @@ -5639,6 +5640,16 @@ static const char readme_msg[] = "\t common_timestamp - to record current timestamp\n" "\t common_cpu - to record the CPU the event happened on\n" "\n" + "\t A hist trigger variable can be:\n" + "\t - a reference to a field e.g. x=current_timestamp,\n" + "\t - a reference to another variable e.g. y=$x,\n" + "\t - a numeric literal: e.g. ms_per_sec=1000,\n" + "\t - an arithmetic expression: e.g. time_secs=current_timestamp/1000\n" + "\n" + "\t hist trigger aritmethic expressions support addition(+), subtraction(-),\n" + "\t multiplication(*) and division(/) operators. An operand can be either a\n" + "\t variable reference, field or numeric literal.\n" + "\n" "\t When a matching event is hit, an entry is added to a hash\n" "\t table using the key(s) and value(s) named, and the value of a\n" "\t sum called 'hitcount' is incremented. Keys and values\n"
Update the tracefs README to describe how hist trigger variables can be created. Signed-off-by: Kalesh Singh <kaleshsingh@google.com> --- kernel/trace/trace.c | 11 +++++++++++ 1 file changed, 11 insertions(+)