The hist patch allows sorting on values only. By allowing to
sort also on the key we can do something like this:
'hist:key=latency:val=hitcount:sort=latency'
latency: 16 hitcount: 3
latency: 17 hitcount: 171
latency: 18 hitcount: 626
latency: 19 hitcount: 594
latency: 20 hitcount: 306
latency: 21 hitcount: 214
latency: 22 hitcount: 232
latency: 23 hitcount: 283
latency: 24 hitcount: 235
latency: 25 hitcount: 105
latency: 26 hitcount: 54
latency: 27 hitcount: 79
latency: 28 hitcount: 214
latency: 29 hitcount: 895
latency: 30 hitcount: 1400
latency: 31 hitcount: 774
latency: 32 hitcount: 653
[...]
The obvious choice for the bool was already taken. I haven't found a
good name for the the flag. I guess it would make sense to refactor the
sorting code so that it doesn't really matter what kind of field it
is.
BTW, I wonder if it would possible to drop the need to always provide
the 'val' argument and just assume the 'val=hitcount' in this case.
Not for inclusion!
Not-Signed-off-by: Daniel Wagner <daniel.wag...@bmw-carit.de>
---
kernel/trace/trace_events_hist.c | 35 +++++++++++++++++++++++++++++++----
1 file changed, 31 insertions(+), 4 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 9a7a675..fe06707 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -89,6 +89,7 @@ enum hist_field_flags {
struct hist_trigger_sort_key {
bool use_hitcount;
bool use_key;
+ bool use_real_key;
bool descending;
unsigned int idx;
};
@@ -260,7 +261,7 @@ static void destroy_hist_fields(struct hist_trigger_data
*hist_data)
}
}
-static inline struct hist_trigger_sort_key *create_default_sort_key(void)
+static inline struct hist_trigger_sort_key *create_hitcount_sort_key(void)
{
struct hist_trigger_sort_key *sort_key;
@@ -273,6 +274,19 @@ static inline struct hist_trigger_sort_key
*create_default_sort_key(void)
return sort_key;
}
+static inline struct hist_trigger_sort_key *create_real_key_sort_key(void)
+{
+ struct hist_trigger_sort_key *sort_key;
+
+ sort_key = kzalloc(sizeof(*sort_key), GFP_KERNEL);
+ if (!sort_key)
+ return ERR_PTR(-ENOMEM);
+
+ sort_key->use_real_key = true;
+
+ return sort_key;
+}
+
static inline struct hist_trigger_sort_key *
create_sort_key(char *field_name, struct hist_trigger_data *hist_data)
{
@@ -280,7 +294,10 @@ create_sort_key(char *field_name, struct hist_trigger_data
*hist_data)
unsigned int i;
if (!strcmp(field_name, "hitcount"))
- return create_default_sort_key();
+ return create_hitcount_sort_key();
+
+ if (!strcmp(field_name, hist_data->key->field->name))
+ return create_real_key_sort_key();
for (i = 0; i < hist_data->n_vals; i++)
if (!strcmp(field_name, hist_data->vals[i]->field->name))
@@ -306,7 +323,7 @@ static int create_sort_keys(struct hist_trigger_data
*hist_data)
int ret = 0;
if (!fields_str) {
- sort_key = create_default_sort_key();
+ sort_key = create_hitcount_sort_key();
if (IS_ERR(sort_key)) {
ret = PTR_ERR(sort_key);
goto out;
@@ -984,6 +1001,12 @@ static int cmp_entries(const struct
hist_trigger_sort_entry **a,
hist_data = entry_a->hist_data;
sort_key = hist_data->sort_key_cur;
+ if (sort_key->use_real_key) {
+ val_a = *(u64 *)entry_a->key;
+ val_b = *(u64 *)entry_b->key;
+ goto out;
+ }
+
if (sort_key->use_key) {
if (memcmp((*a)->key, (*b)->key, hist_data->map->key_size))
ret = 1;
@@ -998,6 +1021,7 @@ static int cmp_entries(const struct
hist_trigger_sort_entry **a,
val_b = atomic64_read(&entry_b->sums[sort_key->idx]);
}
+out:
if (val_a > val_b)
ret = 1;
else if (val_a < val_b)
@@ -1372,7 +1396,10 @@ static int event_hist_trigger_print(struct seq_file *m,
else {
unsigned int idx = hist_data->sort_keys[i]->idx;
- hist_field_print(m, hist_data->vals[idx]);
+ if (hist_data->sort_keys[i]->use_real_key)
+ hist_field_print(m, hist_data->key);
+ else
+ hist_field_print(m, hist_data->vals[idx]);
}
}
--
2.1.0
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