diff options
| author | Tom Zanussi <tom.zanussi@linux.intel.com> | 2018-01-16 05:51:46 +0300 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-03-11 00:05:53 +0300 |
| commit | 2734b629525a9dae5bf217cbf0a9651da93d2108 (patch) | |
| tree | cceda953ecbf5a2ec814399751089c1c9996eb3c /kernel/trace/tracing_map.h | |
| parent | ad42febe51ae0a2e875f507a37a6329277f75fdd (diff) | |
| download | linux-2734b629525a9dae5bf217cbf0a9651da93d2108.tar.xz | |
tracing: Add per-element variable support to tracing_map
In order to allow information to be passed between trace events, add
support for per-element variables to tracing_map. This provides a
means for histograms to associate a value or values with an entry when
it's saved or updated, and retrieved by a subsequent event occurrences.
Variables can be set using tracing_map_set_var() and read using
tracing_map_read_var(). tracing_map_var_set() returns true or false
depending on whether or not the variable has been set or not, which is
important for event-matching applications.
tracing_map_read_var_once() reads the variable and resets it to the
'unset' state, implementing read-once variables, which are also
important for event-matching uses.
Link: http://lkml.kernel.org/r/7fa001108252556f0c6dd9d63145eabfe3370d1a.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/tracing_map.h')
| -rw-r--r-- | kernel/trace/tracing_map.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/trace/tracing_map.h b/kernel/trace/tracing_map.h index de57887c0670..053eb92b2d31 100644 --- a/kernel/trace/tracing_map.h +++ b/kernel/trace/tracing_map.h @@ -10,6 +10,7 @@ #define TRACING_MAP_VALS_MAX 3 #define TRACING_MAP_FIELDS_MAX (TRACING_MAP_KEYS_MAX + \ TRACING_MAP_VALS_MAX) +#define TRACING_MAP_VARS_MAX 16 #define TRACING_MAP_SORT_KEYS_MAX 2 typedef int (*tracing_map_cmp_fn_t) (void *val_a, void *val_b); @@ -137,6 +138,8 @@ struct tracing_map_field { struct tracing_map_elt { struct tracing_map *map; struct tracing_map_field *fields; + atomic64_t *vars; + bool *var_set; void *key; void *private_data; }; @@ -192,6 +195,7 @@ struct tracing_map { int key_idx[TRACING_MAP_KEYS_MAX]; unsigned int n_keys; struct tracing_map_sort_key sort_key; + unsigned int n_vars; atomic64_t hits; atomic64_t drops; }; @@ -241,6 +245,7 @@ tracing_map_create(unsigned int map_bits, extern int tracing_map_init(struct tracing_map *map); extern int tracing_map_add_sum_field(struct tracing_map *map); +extern int tracing_map_add_var(struct tracing_map *map); extern int tracing_map_add_key_field(struct tracing_map *map, unsigned int offset, tracing_map_cmp_fn_t cmp_fn); @@ -260,7 +265,13 @@ extern int tracing_map_cmp_none(void *val_a, void *val_b); extern void tracing_map_update_sum(struct tracing_map_elt *elt, unsigned int i, u64 n); +extern void tracing_map_set_var(struct tracing_map_elt *elt, + unsigned int i, u64 n); +extern bool tracing_map_var_set(struct tracing_map_elt *elt, unsigned int i); extern u64 tracing_map_read_sum(struct tracing_map_elt *elt, unsigned int i); +extern u64 tracing_map_read_var(struct tracing_map_elt *elt, unsigned int i); +extern u64 tracing_map_read_var_once(struct tracing_map_elt *elt, unsigned int i); + extern void tracing_map_set_field_descr(struct tracing_map *map, unsigned int i, unsigned int key_offset, |