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author | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-09-07 00:53:17 +0200 |
---|---|---|
committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-09-26 19:01:10 +0200 |
commit | fde59ab1614942a16dd0ce6f053ae96718f0ee50 (patch) | |
tree | 8a47a526e29c09fc1b2e69d763780db0ce010748 /kernel/trace | |
parent | tracing: Move struct filter_pred into trace_events_filter.c (diff) | |
download | linux-fde59ab1614942a16dd0ce6f053ae96718f0ee50.tar.xz linux-fde59ab1614942a16dd0ce6f053ae96718f0ee50.zip |
tracing/filter: Call filter predicate functions directly via a switch statement
Due to retpolines, indirect calls are much more expensive than direct
calls. The filters have a select set of functions it uses for the
predicates. Instead of using function pointers to call them, create a
filter_pred_fn_call() function that uses a switch statement to call the
predicate functions directly. This gives almost a 10% speedup to the
filter logic.
Using the histogram benchmark:
Before:
# event histogram
#
# trigger info: hist:keys=delta:vals=hitcount:sort=delta:size=2048 if delta > 0 [active]
#
{ delta: 113 } hitcount: 272
{ delta: 114 } hitcount: 840
{ delta: 118 } hitcount: 344
{ delta: 119 } hitcount: 25428
{ delta: 120 } hitcount: 350590
{ delta: 121 } hitcount: 1892484
{ delta: 122 } hitcount: 6205004
{ delta: 123 } hitcount: 11583521
{ delta: 124 } hitcount: 37590979
{ delta: 125 } hitcount: 108308504
{ delta: 126 } hitcount: 131672461
{ delta: 127 } hitcount: 88700598
{ delta: 128 } hitcount: 65939870
{ delta: 129 } hitcount: 45055004
{ delta: 130 } hitcount: 33174464
{ delta: 131 } hitcount: 31813493
{ delta: 132 } hitcount: 29011676
{ delta: 133 } hitcount: 22798782
{ delta: 134 } hitcount: 22072486
{ delta: 135 } hitcount: 17034113
{ delta: 136 } hitcount: 8982490
{ delta: 137 } hitcount: 2865908
{ delta: 138 } hitcount: 980382
{ delta: 139 } hitcount: 1651944
{ delta: 140 } hitcount: 4112073
{ delta: 141 } hitcount: 3963269
{ delta: 142 } hitcount: 1712508
{ delta: 143 } hitcount: 575941
After:
# event histogram
#
# trigger info: hist:keys=delta:vals=hitcount:sort=delta:size=2048 if delta > 0 [active]
#
{ delta: 103 } hitcount: 60
{ delta: 104 } hitcount: 16966
{ delta: 105 } hitcount: 396625
{ delta: 106 } hitcount: 3223400
{ delta: 107 } hitcount: 12053754
{ delta: 108 } hitcount: 20241711
{ delta: 109 } hitcount: 14850200
{ delta: 110 } hitcount: 4946599
{ delta: 111 } hitcount: 3479315
{ delta: 112 } hitcount: 18698299
{ delta: 113 } hitcount: 62388733
{ delta: 114 } hitcount: 95803834
{ delta: 115 } hitcount: 58278130
{ delta: 116 } hitcount: 15364800
{ delta: 117 } hitcount: 5586866
{ delta: 118 } hitcount: 2346880
{ delta: 119 } hitcount: 1131091
{ delta: 120 } hitcount: 620896
{ delta: 121 } hitcount: 236652
{ delta: 122 } hitcount: 105957
{ delta: 123 } hitcount: 119107
{ delta: 124 } hitcount: 54494
{ delta: 125 } hitcount: 63856
{ delta: 126 } hitcount: 64454
{ delta: 127 } hitcount: 34818
{ delta: 128 } hitcount: 41446
{ delta: 129 } hitcount: 51242
{ delta: 130 } hitcount: 28361
{ delta: 131 } hitcount: 23926
The peak before was 126ns per event, after the peak is 114ns, and the
fastest time went from 113ns to 103ns.
Link: https://lkml.kernel.org/r/20220906225529.781407172@goodmis.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r-- | kernel/trace/trace_events_filter.c | 230 |
1 files changed, 157 insertions, 73 deletions
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index c49c689ce4ad..96acc2b71ac7 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -43,10 +43,33 @@ enum filter_op_ids { OPS }; static const char * ops[] = { OPS }; -typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event); +enum filter_pred_fn { + FILTER_PRED_FN_NOP, + FILTER_PRED_FN_64, + FILTER_PRED_FN_S64, + FILTER_PRED_FN_U64, + FILTER_PRED_FN_32, + FILTER_PRED_FN_S32, + FILTER_PRED_FN_U32, + FILTER_PRED_FN_16, + FILTER_PRED_FN_S16, + FILTER_PRED_FN_U16, + FILTER_PRED_FN_8, + FILTER_PRED_FN_S8, + FILTER_PRED_FN_U8, + FILTER_PRED_FN_COMM, + FILTER_PRED_FN_STRING, + FILTER_PRED_FN_STRLOC, + FILTER_PRED_FN_STRRELLOC, + FILTER_PRED_FN_PCHAR_USER, + FILTER_PRED_FN_PCHAR, + FILTER_PRED_FN_CPU, + FILTER_PRED_FN_, + FILTER_PRED_TEST_VISITED, +}; struct filter_pred { - filter_pred_fn_t fn; + enum filter_pred_fn fn_num; u64 val; struct regex regex; unsigned short *ops; @@ -603,44 +626,48 @@ out_free: return ERR_PTR(ret); } +enum pred_cmp_types { + PRED_CMP_TYPE_NOP, + PRED_CMP_TYPE_LT, + PRED_CMP_TYPE_LE, + PRED_CMP_TYPE_GT, + PRED_CMP_TYPE_GE, + PRED_CMP_TYPE_BAND, +}; + #define DEFINE_COMPARISON_PRED(type) \ -static int filter_pred_LT_##type(struct filter_pred *pred, void *event) \ -{ \ - type *addr = (type *)(event + pred->offset); \ - type val = (type)pred->val; \ - return *addr < val; \ -} \ -static int filter_pred_LE_##type(struct filter_pred *pred, void *event) \ +static int filter_pred_##type(struct filter_pred *pred, void *event) \ { \ - type *addr = (type *)(event + pred->offset); \ - type val = (type)pred->val; \ - return *addr <= val; \ -} \ -static int filter_pred_GT_##type(struct filter_pred *pred, void *event) \ -{ \ - type *addr = (type *)(event + pred->offset); \ - type val = (type)pred->val; \ - return *addr > val; \ -} \ -static int filter_pred_GE_##type(struct filter_pred *pred, void *event) \ -{ \ - type *addr = (type *)(event + pred->offset); \ - type val = (type)pred->val; \ - return *addr >= val; \ -} \ -static int filter_pred_BAND_##type(struct filter_pred *pred, void *event) \ -{ \ - type *addr = (type *)(event + pred->offset); \ - type val = (type)pred->val; \ - return !!(*addr & val); \ -} \ -static const filter_pred_fn_t pred_funcs_##type[] = { \ - filter_pred_LE_##type, \ - filter_pred_LT_##type, \ - filter_pred_GE_##type, \ - filter_pred_GT_##type, \ - filter_pred_BAND_##type, \ -}; + switch (pred->op) { \ + case OP_LT: { \ + type *addr = (type *)(event + pred->offset); \ + type val = (type)pred->val; \ + return *addr < val; \ + } \ + case OP_LE: { \ + type *addr = (type *)(event + pred->offset); \ + type val = (type)pred->val; \ + return *addr <= val; \ + } \ + case OP_GT: { \ + type *addr = (type *)(event + pred->offset); \ + type val = (type)pred->val; \ + return *addr > val; \ + } \ + case OP_GE: { \ + type *addr = (type *)(event + pred->offset); \ + type val = (type)pred->val; \ + return *addr >= val; \ + } \ + case OP_BAND: { \ + type *addr = (type *)(event + pred->offset); \ + type val = (type)pred->val; \ + return !!(*addr & val); \ + } \ + default: \ + return 0; \ + } \ +} #define DEFINE_EQUALITY_PRED(size) \ static int filter_pred_##size(struct filter_pred *pred, void *event) \ @@ -849,11 +876,6 @@ static int filter_pred_comm(struct filter_pred *pred, void *event) return cmp ^ pred->not; } -static int filter_pred_none(struct filter_pred *pred, void *event) -{ - return 0; -} - /* * regex_match_foo - Basic regex callbacks * @@ -999,6 +1021,19 @@ static void filter_build_regex(struct filter_pred *pred) } } + +#ifdef CONFIG_FTRACE_STARTUP_TEST +static int test_pred_visited_fn(struct filter_pred *pred, void *event); +#else +static int test_pred_visited_fn(struct filter_pred *pred, void *event) +{ + return 0; +} +#endif + + +static int filter_pred_fn_call(struct filter_pred *pred, void *event); + /* return 1 if event matches, 0 otherwise (discard) */ int filter_match_preds(struct event_filter *filter, void *rec) { @@ -1016,7 +1051,7 @@ int filter_match_preds(struct event_filter *filter, void *rec) for (i = 0; prog[i].pred; i++) { struct filter_pred *pred = prog[i].pred; - int match = pred->fn(pred, rec); + int match = filter_pred_fn_call(pred, rec); if (match == prog[i].when_to_branch) i = prog[i].target; } @@ -1202,10 +1237,10 @@ int filter_assign_type(const char *type) return FILTER_OTHER; } -static filter_pred_fn_t select_comparison_fn(enum filter_op_ids op, - int field_size, int field_is_signed) +static enum filter_pred_fn select_comparison_fn(enum filter_op_ids op, + int field_size, int field_is_signed) { - filter_pred_fn_t fn = NULL; + enum filter_pred_fn fn = FILTER_PRED_FN_NOP; int pred_func_index = -1; switch (op) { @@ -1214,50 +1249,99 @@ static filter_pred_fn_t select_comparison_fn(enum filter_op_ids op, break; default: if (WARN_ON_ONCE(op < PRED_FUNC_START)) - return NULL; + return fn; pred_func_index = op - PRED_FUNC_START; if (WARN_ON_ONCE(pred_func_index > PRED_FUNC_MAX)) - return NULL; + return fn; } switch (field_size) { case 8: if (pred_func_index < 0) - fn = filter_pred_64; + fn = FILTER_PRED_FN_64; else if (field_is_signed) - fn = pred_funcs_s64[pred_func_index]; + fn = FILTER_PRED_FN_S64; else - fn = pred_funcs_u64[pred_func_index]; + fn = FILTER_PRED_FN_U64; break; case 4: if (pred_func_index < 0) - fn = filter_pred_32; + fn = FILTER_PRED_FN_32; else if (field_is_signed) - fn = pred_funcs_s32[pred_func_index]; + fn = FILTER_PRED_FN_S32; else - fn = pred_funcs_u32[pred_func_index]; + fn = FILTER_PRED_FN_U32; break; case 2: if (pred_func_index < 0) - fn = filter_pred_16; + fn = FILTER_PRED_FN_16; else if (field_is_signed) - fn = pred_funcs_s16[pred_func_index]; + fn = FILTER_PRED_FN_S16; else - fn = pred_funcs_u16[pred_func_index]; + fn = FILTER_PRED_FN_U16; break; case 1: if (pred_func_index < 0) - fn = filter_pred_8; + fn = FILTER_PRED_FN_8; else if (field_is_signed) - fn = pred_funcs_s8[pred_func_index]; + fn = FILTER_PRED_FN_S8; else - fn = pred_funcs_u8[pred_func_index]; + fn = FILTER_PRED_FN_U8; break; } return fn; } + +static int filter_pred_fn_call(struct filter_pred *pred, void *event) +{ + switch (pred->fn_num) { + case FILTER_PRED_FN_64: + return filter_pred_64(pred, event); + case FILTER_PRED_FN_S64: + return filter_pred_s64(pred, event); + case FILTER_PRED_FN_U64: + return filter_pred_u64(pred, event); + case FILTER_PRED_FN_32: + return filter_pred_32(pred, event); + case FILTER_PRED_FN_S32: + return filter_pred_s32(pred, event); + case FILTER_PRED_FN_U32: + return filter_pred_u32(pred, event); + case FILTER_PRED_FN_16: + return filter_pred_16(pred, event); + case FILTER_PRED_FN_S16: + return filter_pred_s16(pred, event); + case FILTER_PRED_FN_U16: + return filter_pred_u16(pred, event); + case FILTER_PRED_FN_8: + return filter_pred_8(pred, event); + case FILTER_PRED_FN_S8: + return filter_pred_s8(pred, event); + case FILTER_PRED_FN_U8: + return filter_pred_u8(pred, event); + case FILTER_PRED_FN_COMM: + return filter_pred_comm(pred, event); + case FILTER_PRED_FN_STRING: + return filter_pred_string(pred, event); + case FILTER_PRED_FN_STRLOC: + return filter_pred_strloc(pred, event); + case FILTER_PRED_FN_STRRELLOC: + return filter_pred_strrelloc(pred, event); + case FILTER_PRED_FN_PCHAR_USER: + return filter_pred_pchar_user(pred, event); + case FILTER_PRED_FN_PCHAR: + return filter_pred_pchar(pred, event); + case FILTER_PRED_FN_CPU: + return filter_pred_cpu(pred, event); + case FILTER_PRED_TEST_VISITED: + return test_pred_visited_fn(pred, event); + default: + return 0; + } +} + /* Called when a predicate is encountered by predicate_parse() */ static int parse_pred(const char *str, void *data, int pos, struct filter_parse_error *pe, @@ -1351,7 +1435,7 @@ static int parse_pred(const char *str, void *data, parse_error(pe, FILT_ERR_IP_FIELD_ONLY, pos + i); goto err_free; } - pred->fn = filter_pred_none; + pred->fn_num = FILTER_PRED_FN_NOP; /* * Quotes are not required, but if they exist then we need @@ -1429,16 +1513,16 @@ static int parse_pred(const char *str, void *data, filter_build_regex(pred); if (field->filter_type == FILTER_COMM) { - pred->fn = filter_pred_comm; + pred->fn_num = FILTER_PRED_FN_COMM; } else if (field->filter_type == FILTER_STATIC_STRING) { - pred->fn = filter_pred_string; + pred->fn_num = FILTER_PRED_FN_STRING; pred->regex.field_len = field->size; } else if (field->filter_type == FILTER_DYN_STRING) { - pred->fn = filter_pred_strloc; + pred->fn_num = FILTER_PRED_FN_STRLOC; } else if (field->filter_type == FILTER_RDYN_STRING) - pred->fn = filter_pred_strrelloc; + pred->fn_num = FILTER_PRED_FN_STRRELLOC; else { if (!ustring_per_cpu) { @@ -1449,9 +1533,9 @@ static int parse_pred(const char *str, void *data, } if (ustring) - pred->fn = filter_pred_pchar_user; + pred->fn_num = FILTER_PRED_FN_PCHAR_USER; else - pred->fn = filter_pred_pchar; + pred->fn_num = FILTER_PRED_FN_PCHAR; } /* go past the last quote */ i++; @@ -1499,10 +1583,10 @@ static int parse_pred(const char *str, void *data, pred->val = val; if (field->filter_type == FILTER_CPU) - pred->fn = filter_pred_cpu; + pred->fn_num = FILTER_PRED_FN_CPU; else { - pred->fn = select_comparison_fn(pred->op, field->size, - field->is_signed); + pred->fn_num = select_comparison_fn(pred->op, field->size, + field->is_signed); if (pred->op == OP_NE) pred->not = 1; } @@ -2309,7 +2393,7 @@ static void update_pred_fn(struct event_filter *filter, char *fields) struct filter_pred *pred = prog[i].pred; struct ftrace_event_field *field = pred->field; - WARN_ON_ONCE(!pred->fn); + WARN_ON_ONCE(pred->fn_num == FILTER_PRED_FN_NOP); if (!field) { WARN_ONCE(1, "all leafs should have field defined %d", i); @@ -2319,7 +2403,7 @@ static void update_pred_fn(struct event_filter *filter, char *fields) if (!strchr(fields, *field->name)) continue; - pred->fn = test_pred_visited_fn; + pred->fn_num = FILTER_PRED_TEST_VISITED; } } |