Files
linux/tools/perf/util/evsel_fprintf.c
Ian Rogers 979e87ab1f perf symbol: Add setters for bitfields sharing a byte to avoid concurrent update issues
A problem with putting bitfields into struct symbol is that other bits in
the symbol could be updated concurrently and only one update to the
underlying storage unit happen, leading to lost updates.

To avoid this, use atomics to atomically read or set part of 16-bits
of flags in the symbol. Add accessors to simplify this.

The idle value has 3 values in preparation for a later change that
will lazily update it.

Assisted-by: Gemini:gemini-3.1-pro-preview
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Honglei Wang <jameshongleiwang@126.com>
Cc: Jan Polensky <japo@linux.ibm.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-03 16:53:45 -03:00

259 lines
6.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <inttypes.h>
#include <stdio.h>
#include <stdbool.h>
#include "util/evlist.h"
#include "evsel.h"
#include "util/evsel_fprintf.h"
#include "util/event.h"
#include "callchain.h"
#include "map.h"
#include "strlist.h"
#include "symbol.h"
#include "srcline.h"
#include "dso.h"
#ifdef HAVE_LIBTRACEEVENT
#include <event-parse.h>
#endif
static int comma_fprintf(FILE *fp, bool *first, const char *fmt, ...)
{
va_list args;
int ret = 0;
if (!*first) {
ret += fprintf(fp, ",");
} else {
ret += fprintf(fp, ":");
*first = false;
}
va_start(args, fmt);
ret += vfprintf(fp, fmt, args);
va_end(args);
return ret;
}
static int __print_attr__fprintf(FILE *fp, const char *name, const char *val, void *priv)
{
return comma_fprintf(fp, (bool *)priv, " %s: %s", name, val);
}
int evsel__fprintf(struct evsel *evsel, struct perf_attr_details *details, FILE *fp)
{
bool first = true;
int printed = 0;
if (details->event_group) {
struct evsel *pos;
if (!evsel__is_group_leader(evsel))
return 0;
if (evsel->core.nr_members > 1)
printed += fprintf(fp, "%s{", evsel->group_name ?: "");
printed += fprintf(fp, "%s", evsel__name(evsel));
for_each_group_member(pos, evsel)
printed += fprintf(fp, ",%s", evsel__name(pos));
if (evsel->core.nr_members > 1)
printed += fprintf(fp, "}");
goto out;
}
printed += fprintf(fp, "%s", evsel__name(evsel));
if (details->verbose) {
printed += perf_event_attr__fprintf(fp, &evsel->core.attr,
__print_attr__fprintf, &first);
} else if (details->freq) {
const char *term = "sample_freq";
if (!evsel->core.attr.freq)
term = "sample_period";
printed += comma_fprintf(fp, &first, " %s=%" PRIu64,
term, (u64)evsel->core.attr.sample_freq);
}
#ifdef HAVE_LIBTRACEEVENT
if (details->trace_fields) {
struct tep_format_field *field;
const struct tep_event *tp_format;
if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT) {
printed += comma_fprintf(fp, &first, " (not a tracepoint)");
goto out;
}
tp_format = evsel__tp_format(evsel);
field = tp_format ? tp_format->format.fields : NULL;
if (field == NULL) {
printed += comma_fprintf(fp, &first, " (no trace field)");
goto out;
}
printed += comma_fprintf(fp, &first, " trace_fields: %s", field->name);
field = field->next;
while (field) {
printed += comma_fprintf(fp, &first, "%s", field->name);
field = field->next;
}
}
#endif
out:
fputc('\n', fp);
return ++printed;
}
int sample__fprintf_callchain(struct perf_sample *sample, int left_alignment,
unsigned int print_opts, struct callchain_cursor *cursor,
struct strlist *bt_stop_list, FILE *fp)
{
int printed = 0;
struct callchain_cursor_node *node;
int print_ip = print_opts & EVSEL__PRINT_IP;
int print_sym = print_opts & EVSEL__PRINT_SYM;
int print_dso = print_opts & EVSEL__PRINT_DSO;
int print_dsoff = print_opts & EVSEL__PRINT_DSOFF;
int print_symoffset = print_opts & EVSEL__PRINT_SYMOFFSET;
int print_oneline = print_opts & EVSEL__PRINT_ONELINE;
int print_srcline = print_opts & EVSEL__PRINT_SRCLINE;
int print_unknown_as_addr = print_opts & EVSEL__PRINT_UNKNOWN_AS_ADDR;
int print_arrow = print_opts & EVSEL__PRINT_CALLCHAIN_ARROW;
int print_skip_ignored = print_opts & EVSEL__PRINT_SKIP_IGNORED;
char s = print_oneline ? ' ' : '\t';
bool first = true;
if (cursor == NULL)
return fprintf(fp, "<not enough memory for the callchain cursor>%s", print_oneline ? "" : "\n");
if (sample->callchain) {
callchain_cursor_commit(cursor);
while (1) {
struct symbol *sym;
struct map *map;
u64 addr = 0;
node = callchain_cursor_current(cursor);
if (!node)
break;
sym = node->ms.sym;
map = node->ms.map;
if (sym && symbol__ignore(sym) && print_skip_ignored)
goto next;
printed += fprintf(fp, "%-*.*s", left_alignment, left_alignment, " ");
if (print_arrow && !first)
printed += fprintf(fp, " <-");
if (map)
addr = map__map_ip(map, node->ip);
if (print_ip)
printed += fprintf(fp, "%c%16" PRIx64, s, node->ip);
if (print_sym) {
struct addr_location node_al;
addr_location__init(&node_al);
printed += fprintf(fp, " ");
node_al.addr = addr;
node_al.map = map__get(map);
if (sample->deferred_callchain &&
sample->deferred_cookie == node->ip) {
printed += fprintf(fp, "(cookie)");
} else if (print_symoffset) {
printed += __symbol__fprintf_symname_offs(sym, &node_al,
print_unknown_as_addr,
true, fp);
} else {
printed += __symbol__fprintf_symname(sym, &node_al,
print_unknown_as_addr, fp);
}
addr_location__exit(&node_al);
}
if (print_dso && (!sym || !symbol__inlined(sym)))
printed += map__fprintf_dsoname_dsoff(map, print_dsoff, addr, fp);
if (print_srcline) {
if (node->srcline)
printed += fprintf(fp, "\n %s", node->srcline);
else
printed += map__fprintf_srcline(map, addr, "\n ", fp);
}
if (sym && symbol__inlined(sym))
printed += fprintf(fp, " (inlined)");
if (!print_oneline)
printed += fprintf(fp, "\n");
/* Add srccode here too? */
if (bt_stop_list && sym &&
strlist__has_entry(bt_stop_list, sym->name)) {
break;
}
first = false;
next:
callchain_cursor_advance(cursor);
}
}
return printed;
}
int sample__fprintf_sym(struct perf_sample *sample, struct addr_location *al,
int left_alignment, unsigned int print_opts,
struct callchain_cursor *cursor, struct strlist *bt_stop_list, FILE *fp)
{
int printed = 0;
int print_ip = print_opts & EVSEL__PRINT_IP;
int print_sym = print_opts & EVSEL__PRINT_SYM;
int print_dso = print_opts & EVSEL__PRINT_DSO;
int print_dsoff = print_opts & EVSEL__PRINT_DSOFF;
int print_symoffset = print_opts & EVSEL__PRINT_SYMOFFSET;
int print_srcline = print_opts & EVSEL__PRINT_SRCLINE;
int print_unknown_as_addr = print_opts & EVSEL__PRINT_UNKNOWN_AS_ADDR;
if (cursor != NULL) {
printed += sample__fprintf_callchain(sample, left_alignment, print_opts,
cursor, bt_stop_list, fp);
} else {
printed += fprintf(fp, "%-*.*s", left_alignment, left_alignment, " ");
if (print_ip)
printed += fprintf(fp, "%16" PRIx64, sample->ip);
if (print_sym) {
printed += fprintf(fp, " ");
if (print_symoffset) {
printed += __symbol__fprintf_symname_offs(al->sym, al,
print_unknown_as_addr,
true, fp);
} else {
printed += __symbol__fprintf_symname(al->sym, al,
print_unknown_as_addr, fp);
}
}
if (print_dso)
printed += map__fprintf_dsoname_dsoff(al->map, print_dsoff, al->addr, fp);
if (print_srcline)
printed += map__fprintf_srcline(al->map, al->addr, "\n ", fp);
}
return printed;
}