diff options
| author | Steven Rostedt <srostedt@redhat.com> | 2011-01-27 23:16:51 -0500 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2011-02-07 20:56:19 -0500 |
| commit | 43cd414552d8137157e926e46361678ea867e476 (patch) | |
| tree | cbb50e071a8149e2da7be995166f487bbcb5172a /kernel/trace/trace.h | |
| parent | ec126cac23945de12eb2d103374e1f7ee97c5595 (diff) | |
tracing/filter: Optimize filter by folding the tree
There are many cases that a filter will contain multiple ORs or
ANDs together near the leafs. Walking up and down the tree to get
to the next compare can be a waste.
If there are several ORs or ANDs together, fold them into a single
pred and allocate an array of the conditions that they check.
This will speed up the filter by linearly walking an array
and can still break out if a short circuit condition is met.
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.h')
| -rw-r--r-- | kernel/trace/trace.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index bba34a72c780..d754330934bb 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -678,6 +678,7 @@ struct event_subsystem { #define FILTER_PRED_INVALID ((unsigned short)-1) #define FILTER_PRED_IS_RIGHT (1 << 15) +#define FILTER_PRED_FOLD (1 << 15) struct filter_pred; struct regex; @@ -704,7 +705,16 @@ struct filter_pred { filter_pred_fn_t fn; u64 val; struct regex regex; - char *field_name; + /* + * Leaf nodes use field_name, ops is used by AND and OR + * nodes. The field_name is always freed when freeing a pred. + * We can overload field_name for ops and have it freed + * as well. + */ + union { + char *field_name; + unsigned short *ops; + }; int offset; int not; int op; |