From fdf5b679864b8a1165712164b8f17debeb6b10b6 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 25 Oct 2016 16:14:28 -0400 Subject: [PATCH] tracing: Optimise comparison filters and fix binary and for 64 bit Currently the filter logic for comparisons (like greater-than and less-than) are used, they share the same function and a switch statement is used to jump to the comparison type to perform. This is done in the extreme hot path of the tracing code, and it does not take much more space to create a unique comparison function to perform each type of comparison and remove the switch statement. Also, a bug was found where the binary and operation for 64 bits could fail if the resulting bits were greater than 32 bits, because the result was passed into a 32 bit variable. This was fixed when adding the separate binary and function. Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_filter.c | 80 +++++++++++++++++++++++--------------- 1 file changed, 48 insertions(+), 32 deletions(-) diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index e1c7e2c..1ba7a6b8 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -145,34 +145,50 @@ struct pred_stack { /* If not of not match is equal to not of not, then it is a match */ #define DEFINE_COMPARISON_PRED(type) \ -static int filter_pred_##type(struct filter_pred *pred, void *event) \ +static int filter_pred_LT_##type(struct filter_pred *pred, void *event) \ { \ type *addr = (type *)(event + pred->offset); \ type val = (type)pred->val; \ - int match = 0; \ - \ - switch (pred->op) { \ - case OP_LT: \ - match = (*addr < val); \ - break; \ - case OP_LE: \ - match = (*addr <= val); \ - break; \ - case OP_GT: \ - match = (*addr > val); \ - break; \ - case OP_GE: \ - match = (*addr >= val); \ - break; \ - case OP_BAND: \ - match = (*addr & val); \ - break; \ - default: \ - break; \ - } \ - \ + int match = (*addr < val); \ return !!match == !pred->not; \ -} +} \ +static int filter_pred_LE_##type(struct filter_pred *pred, void *event) \ +{ \ + type *addr = (type *)(event + pred->offset); \ + type val = (type)pred->val; \ + int match = (*addr <= val); \ + return !!match == !pred->not; \ +} \ +static int filter_pred_GT_##type(struct filter_pred *pred, void *event) \ +{ \ + type *addr = (type *)(event + pred->offset); \ + type val = (type)pred->val; \ + int match = (*addr > val); \ + return !!match == !pred->not; \ +} \ +static int filter_pred_GE_##type(struct filter_pred *pred, void *event) \ +{ \ + type *addr = (type *)(event + pred->offset); \ + type val = (type)pred->val; \ + int match = (*addr >= val); \ + return !!match == !pred->not; \ +} \ +static int filter_pred_BAND_##type(struct filter_pred *pred, void *event) \ +{ \ + type *addr = (type *)(event + pred->offset); \ + type val = (type)pred->val; \ + int match = !!(*addr & val); \ + return match == !pred->not; \ +} \ +static const filter_pred_fn_t pred_funcs_##type[] = { \ + filter_pred_LT_##type, \ + filter_pred_LE_##type, \ + filter_pred_GT_##type, \ + filter_pred_GE_##type, \ + filter_pred_BAND_##type, \ +}; + +#define PRED_FUNC_START OP_LT #define DEFINE_EQUALITY_PRED(size) \ static int filter_pred_##size(struct filter_pred *pred, void *event) \ @@ -982,33 +998,33 @@ static filter_pred_fn_t select_comparison_fn(int op, int field_size, if (op == OP_EQ || op == OP_NE) fn = filter_pred_64; else if (field_is_signed) - fn = filter_pred_s64; + fn = pred_funcs_s64[op - PRED_FUNC_START]; else - fn = filter_pred_u64; + fn = pred_funcs_u64[op - PRED_FUNC_START]; break; case 4: if (op == OP_EQ || op == OP_NE) fn = filter_pred_32; else if (field_is_signed) - fn = filter_pred_s32; + fn = pred_funcs_s32[op - PRED_FUNC_START]; else - fn = filter_pred_u32; + fn = pred_funcs_u32[op - PRED_FUNC_START]; break; case 2: if (op == OP_EQ || op == OP_NE) fn = filter_pred_16; else if (field_is_signed) - fn = filter_pred_s16; + fn = pred_funcs_s16[op - PRED_FUNC_START]; else - fn = filter_pred_u16; + fn = pred_funcs_u16[op - PRED_FUNC_START]; break; case 1: if (op == OP_EQ || op == OP_NE) fn = filter_pred_8; else if (field_is_signed) - fn = filter_pred_s8; + fn = pred_funcs_s8[op - PRED_FUNC_START]; else - fn = filter_pred_u8; + fn = pred_funcs_u8[op - PRED_FUNC_START]; break; } -- 2.7.4