[PATCH 2/2] perf env: Cache the arch specific strerrno function in perf_env__arch_strerrno()

Arnaldo Carvalho de Melo
2023-12-01T20:31:06Z

So that we don't have to go thru the series of strcmp(arch) calls for
each id -> string translation.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/trace/beauty/arch_errno_names.sh | 6 +++---
tools/perf/trace/beauty/beauty.h | 2 --
tools/perf/util/env.c | 6 ++++--
tools/perf/util/env.h | 5 +++++
4 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/tools/perf/trace/beauty/arch_errno_names.sh b/tools/perf/trace/beauty/arch_errno_names.sh
index b6e0767b4b34e46a..7df4bf5b55a3cc2a 100755
--- a/tools/perf/trace/beauty/arch_errno_names.sh
+++ b/tools/perf/trace/beauty/arch_errno_names.sh
@@ -57,13 +57,13 @@ create_arch_errno_table_func()
archlist="$1"
default="$2"

- printf 'const char *arch_syscalls__strerrno(const char *arch, int err)\n'
+ printf 'arch_syscalls__strerrno_t *arch_syscalls__strerrno_function(const char *arch)\n'
printf '{\n'
for arch in $archlist; do
printf '\tif (!strcmp(arch, "%s"))\n' $(arch_string "$arch")
- printf '\t\treturn errno_to_name__%s(err);\n' $(arch_string "$arch")
+ printf '\t\treturn errno_to_name__%s;\n' $(arch_string "$arch")
done
- printf '\treturn errno_to_name__%s(err);\n' $(arch_string "$default")
+ printf '\treturn errno_to_name__%s;\n' $(arch_string "$default")
printf '}\n'
}

diff --git a/tools/perf/trace/beauty/beauty.h b/tools/perf/trace/beauty/beauty.h
index 788e8f6bd90eb753..9feb794f5c6e15f4 100644
--- a/tools/perf/trace/beauty/beauty.h
+++ b/tools/perf/trace/beauty/beauty.h
@@ -251,6 +251,4 @@ size_t open__scnprintf_flags(unsigned long flags, char *bf, size_t size, bool sh
void syscall_arg__set_ret_scnprintf(struct syscall_arg *arg,
size_t (*ret_scnprintf)(char *bf, size_t size, struct syscall_arg *arg));

-const char *arch_syscalls__strerrno(const char *arch, int err);
-
#endif /* _PERF_TRACE_BEAUTY_H */
diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index fdd62ea00173ccf5..2845b9f4694591be 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -456,8 +456,10 @@ const char *perf_env__arch(struct perf_env *env)

const char *perf_env__arch_strerrno(struct perf_env *env, int err)
{
- const char *arch_name = perf_env__arch(env);
- return arch_syscalls__strerrno(arch_name, err);
+ if (env->arch_strerrno == NULL)
+ env->arch_strerrno = arch_syscalls__strerrno_function(perf_env__arch(env));
+
+ return env->arch_strerrno ? env->arch_strerrno(err) : "no arch specific strerrno function";
}

const char *perf_env__cpuid(struct perf_env *env)
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index 79f371879f45bafc..bf7e3c4c211f971e 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -53,6 +53,10 @@ struct pmu_caps {
char *pmu_name;
};

+typedef const char *(arch_syscalls__strerrno_t)(int err);
+
+arch_syscalls__strerrno_t *arch_syscalls__strerrno_function(const char *arch);
+
struct perf_env {
char *hostname;
char *os_release;
@@ -135,6 +139,7 @@ struct perf_env {
*/
bool enabled;
} clock;
+ arch_syscalls__strerrno_t *arch_strerrno;
};

enum perf_compress_type {
--
2.41.0