diff options
| author | Tom Zanussi <zanussi@kernel.org> | 2021-09-02 15:57:12 -0500 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-09-08 15:29:16 -0400 |
| commit | c910db943d35d4ac4b77570ece76e0799af24233 (patch) | |
| tree | 6d6bcf3cbd73b5e82ad79e25dbe90dd40d56491d | |
| parent | 0be083cee42ec78ba6f9148f5b12a00aa2fb8bd3 (diff) | |
tracing: Dynamically allocate the per-elt hist_elt_data array
Setting the hist_elt_data.field_var_str[] array unconditionally to a
size of SYNTH_FIELD_MAX elements wastes space unnecessarily. The
actual number of elements needed can be calculated at run-time
instead.
In most cases, this will save a lot of space since it's a per-elt
array which isn't normally close to being full. It also allows us to
increase SYNTH_FIELD_MAX without worrying about even more wastage when
we do that.
Link: https://lkml.kernel.org/r/d52ae0ad5e1b59af7c4f54faf3fc098461fd82b3.camel@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/trace_events_hist.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 9d91b1c06957..a6061a69aa84 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -508,7 +508,8 @@ struct track_data { struct hist_elt_data { char *comm; u64 *var_ref_vals; - char *field_var_str[SYNTH_FIELDS_MAX]; + char **field_var_str; + int n_field_var_str; }; struct snapshot_context { @@ -1401,9 +1402,11 @@ static void hist_elt_data_free(struct hist_elt_data *elt_data) { unsigned int i; - for (i = 0; i < SYNTH_FIELDS_MAX; i++) + for (i = 0; i < elt_data->n_field_var_str; i++) kfree(elt_data->field_var_str[i]); + kfree(elt_data->field_var_str); + kfree(elt_data->comm); kfree(elt_data); } @@ -1451,6 +1454,13 @@ static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt) size = STR_VAR_LEN_MAX; + elt_data->field_var_str = kcalloc(n_str, sizeof(char *), GFP_KERNEL); + if (!elt_data->field_var_str) { + hist_elt_data_free(elt_data); + return -EINVAL; + } + elt_data->n_field_var_str = n_str; + for (i = 0; i < n_str; i++) { elt_data->field_var_str[i] = kzalloc(size, GFP_KERNEL); if (!elt_data->field_var_str[i]) { |