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linux/tools/perf/util/branch.h
Kan Liang 1f2b7fbb04 perf annotate: Save branch counters for each block
When annotating a basic block, it's useful to display the occurrences
of other events in the block.

The branch counter feature is only available for newer Intel platforms.

So a dedicated option to display the branch counters is not introduced.

Reuse the existing --total-cycles option, which triggers the annotation
of a basic block and displays the cycle-related annotation.

When the branch counters information is available, the branch counters
are automatically appended after all the cycle-related annotation.

Accounting the branch counters as well when accounting the cycles in
hist__account_cycles().

In 'struct annotated_branch', introduce a br_cntr array to save the
accumulation of each branch counter.

In a sample, all the branch counters for a branch are saved in a u64
space.

Because the saturation of a branch counter is small, e.g., for Intel
Sierra Forest, the saturation is only 3.

Add ANNOTATION__BR_CNTR_SATURATED_FLAG to indicate if a branch counter
once saturated. That can be used to indicate a potential event lost
because of the saturation.

Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240813160208.2493643-5-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-08-14 10:20:40 -03:00

96 lines
2.2 KiB
C

#ifndef _PERF_BRANCH_H
#define _PERF_BRANCH_H 1
/*
* The linux/stddef.h isn't need here, but is needed for __always_inline used
* in files included from uapi/linux/perf_event.h such as
* /usr/include/linux/swab.h and /usr/include/linux/byteorder/little_endian.h,
* detected in at least musl libc, used in Alpine Linux. -acme
*/
#include <stdio.h>
#include <linux/perf_event.h>
#include <linux/types.h>
#include "util/map_symbol.h"
#include "util/sample.h"
struct branch_flags {
union {
u64 value;
struct {
u64 mispred:1;
u64 predicted:1;
u64 in_tx:1;
u64 abort:1;
u64 cycles:16;
u64 type:4;
u64 spec:2;
u64 new_type:4;
u64 priv:3;
u64 reserved:31;
};
};
};
struct branch_info {
struct addr_map_symbol from;
struct addr_map_symbol to;
struct branch_flags flags;
u64 branch_stack_cntr;
char *srcline_from;
char *srcline_to;
};
struct branch_entry {
u64 from;
u64 to;
struct branch_flags flags;
};
struct branch_stack {
u64 nr;
u64 hw_idx;
struct branch_entry entries[];
};
/*
* The hw_idx is only available when PERF_SAMPLE_BRANCH_HW_INDEX is applied.
* Otherwise, the output format of a sample with branch stack is
* struct branch_stack {
* u64 nr;
* struct branch_entry entries[0];
* }
* Check whether the hw_idx is available,
* and return the corresponding pointer of entries[0].
*/
static inline struct branch_entry *perf_sample__branch_entries(struct perf_sample *sample)
{
u64 *entry = (u64 *)sample->branch_stack;
entry++;
if (sample->no_hw_idx)
return (struct branch_entry *)entry;
return (struct branch_entry *)(++entry);
}
struct branch_type_stat {
bool branch_to;
u64 counts[PERF_BR_MAX];
u64 new_counts[PERF_BR_NEW_MAX];
u64 cond_fwd;
u64 cond_bwd;
u64 cross_4k;
u64 cross_2m;
};
void branch_type_count(struct branch_type_stat *st, struct branch_flags *flags,
u64 from, u64 to);
const char *branch_type_name(int type);
const char *branch_new_type_name(int new_type);
const char *get_branch_type(struct branch_entry *e);
void branch_type_stat_display(FILE *fp, const struct branch_type_stat *st);
int branch_type_str(const struct branch_type_stat *st, char *bf, int bfsize);
const char *branch_spec_desc(int spec);
#endif /* _PERF_BRANCH_H */