lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

tracing/filter: Optimize filter by folding the tree

Browse Source 
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>
This commit is contained in:
Steven Rostedt
2011-01-27 23:16:51 -05:00
committed by Steven Rostedt
parent ec126cac23
commit 43cd414552
2 changed files with 235 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
kernel/trace/trace.h
View File

@@ -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;