linux/tools/perf/util/branch.c
Anshuman Khandual cedd3614e5 perf: Add irq and exception return branch types
This expands generic branch type classification by adding two more entries
there in i.e irq and exception return. Also updates the x86 implementation
to process X86_BR_IRET and X86_BR_IRQ records as appropriate. This changes
branch types reported to user space on x86 platform but it should not be a
problem. The possible scenarios and impacts are enumerated here.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1645681014-3346-1-git-send-email-anshuman.khandual@arm.com
2022-03-01 16:19:01 +01:00

149 lines
2.9 KiB
C

#include "util/map_symbol.h"
#include "util/branch.h"
#include <linux/kernel.h>
static bool cross_area(u64 addr1, u64 addr2, int size)
{
u64 align1, align2;
align1 = addr1 & ~(size - 1);
align2 = addr2 & ~(size - 1);
return (align1 != align2) ? true : false;
}
#define AREA_4K 4096
#define AREA_2M (2 * 1024 * 1024)
void branch_type_count(struct branch_type_stat *st, struct branch_flags *flags,
u64 from, u64 to)
{
if (flags->type == PERF_BR_UNKNOWN || from == 0)
return;
st->counts[flags->type]++;
if (flags->type == PERF_BR_COND) {
if (to > from)
st->cond_fwd++;
else
st->cond_bwd++;
}
if (cross_area(from, to, AREA_2M))
st->cross_2m++;
else if (cross_area(from, to, AREA_4K))
st->cross_4k++;
}
const char *branch_type_name(int type)
{
const char *branch_names[PERF_BR_MAX] = {
"N/A",
"COND",
"UNCOND",
"IND",
"CALL",
"IND_CALL",
"RET",
"SYSCALL",
"SYSRET",
"COND_CALL",
"COND_RET",
"ERET",
"IRQ"
};
if (type >= 0 && type < PERF_BR_MAX)
return branch_names[type];
return NULL;
}
void branch_type_stat_display(FILE *fp, struct branch_type_stat *st)
{
u64 total = 0;
int i;
for (i = 0; i < PERF_BR_MAX; i++)
total += st->counts[i];
if (total == 0)
return;
fprintf(fp, "\n#");
fprintf(fp, "\n# Branch Statistics:");
fprintf(fp, "\n#");
if (st->cond_fwd > 0) {
fprintf(fp, "\n%8s: %5.1f%%",
"COND_FWD",
100.0 * (double)st->cond_fwd / (double)total);
}
if (st->cond_bwd > 0) {
fprintf(fp, "\n%8s: %5.1f%%",
"COND_BWD",
100.0 * (double)st->cond_bwd / (double)total);
}
if (st->cross_4k > 0) {
fprintf(fp, "\n%8s: %5.1f%%",
"CROSS_4K",
100.0 * (double)st->cross_4k / (double)total);
}
if (st->cross_2m > 0) {
fprintf(fp, "\n%8s: %5.1f%%",
"CROSS_2M",
100.0 * (double)st->cross_2m / (double)total);
}
for (i = 0; i < PERF_BR_MAX; i++) {
if (st->counts[i] > 0)
fprintf(fp, "\n%8s: %5.1f%%",
branch_type_name(i),
100.0 *
(double)st->counts[i] / (double)total);
}
}
static int count_str_scnprintf(int idx, const char *str, char *bf, int size)
{
return scnprintf(bf, size, "%s%s", (idx) ? " " : " (", str);
}
int branch_type_str(struct branch_type_stat *st, char *bf, int size)
{
int i, j = 0, printed = 0;
u64 total = 0;
for (i = 0; i < PERF_BR_MAX; i++)
total += st->counts[i];
if (total == 0)
return 0;
if (st->cond_fwd > 0)
printed += count_str_scnprintf(j++, "COND_FWD", bf + printed, size - printed);
if (st->cond_bwd > 0)
printed += count_str_scnprintf(j++, "COND_BWD", bf + printed, size - printed);
for (i = 0; i < PERF_BR_MAX; i++) {
if (i == PERF_BR_COND)
continue;
if (st->counts[i] > 0)
printed += count_str_scnprintf(j++, branch_type_name(i), bf + printed, size - printed);
}
if (st->cross_4k > 0)
printed += count_str_scnprintf(j++, "CROSS_4K", bf + printed, size - printed);
if (st->cross_2m > 0)
printed += count_str_scnprintf(j++, "CROSS_2M", bf + printed, size - printed);
return printed;
}