This is a note to let you know that I've just added the patch titled
perf record: Lazy load kernel symbols
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf-record-lazy-load-kernel-symbols.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2ac5c718173e7a88dc3c2ab2ef77339cb40e3550
Author: Ian Rogers <irogers@xxxxxxxxxx>
Date: Thu Nov 2 10:56:44 2023 -0700
perf record: Lazy load kernel symbols
[ Upstream commit 1a27fc01700fbff2f205000edf0d1d315b5f85cc ]
Commit 5b7ba82a75915e73 ("perf symbols: Load kernel maps before using")
changed it so that loading a kernel DSO would cause the symbols for the
DSO to be eagerly loaded.
For 'perf record' this is overhead as the symbols won't be used. Add a
field to 'struct symbol_conf' to control the behavior and disable it for
'perf record' and 'perf inject'.
Reviewed-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Athira Jajeev <atrajeev@xxxxxxxxxxxxxxxxxx>
Cc: Changbin Du <changbin.du@xxxxxxxxxx>
Cc: Colin Ian King <colin.i.king@xxxxxxxxx>
Cc: Dmitrii Dolgov <9erthalion6@xxxxxxxxx>
Cc: German Gomez <german.gomez@xxxxxxx>
Cc: Huacai Chen <chenhuacai@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: James Clark <james.clark@xxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: K Prateek Nayak <kprateek.nayak@xxxxxxx>
Cc: Kajol Jain <kjain@xxxxxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Leo Yan <leo.yan@xxxxxxxxxx>
Cc: Li Dong <lidong@xxxxxxxx>
Cc: Liam Howlett <liam.howlett@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Miguel Ojeda <ojeda@xxxxxxxxxx>
Cc: Ming Wang <wangming01@xxxxxxxxxxx>
Cc: Nick Terrell <terrelln@xxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ravi Bangoria <ravi.bangoria@xxxxxxx>
Cc: Sandipan Das <sandipan.das@xxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Steinar H. Gunderson <sesse@xxxxxxxxxx>
Cc: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx>
Cc: Wenyu Liu <liuwenyu7@xxxxxxxxxx>
Cc: Yang Jihong <yangjihong1@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231102175735.2272696-3-irogers@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Stable-dep-of: aaf494cf483a ("perf annotate: Fix annotation_calc_lines() to pass correct address to get_srcline()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index c8cf2fdd9cff9..eb3ef5c24b662 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -2265,6 +2265,12 @@ int cmd_inject(int argc, const char **argv)
"perf inject [<options>]",
NULL
};
+
+ if (!inject.itrace_synth_opts.set) {
+ /* Disable eager loading of kernel symbols that adds overhead to perf inject. */
+ symbol_conf.lazy_load_kernel_maps = true;
+ }
+
#ifndef HAVE_JITDUMP
set_option_nobuild(options, 'j', "jit", "NO_LIBELF=1", true);
#endif
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index ea80bf4dc4343..5c54fda63b581 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -3936,6 +3936,8 @@ int cmd_record(int argc, const char **argv)
# undef set_nobuild
#endif
+ /* Disable eager loading of kernel symbols that adds overhead to perf record. */
+ symbol_conf.lazy_load_kernel_maps = true;
rec->opts.affinity = PERF_AFFINITY_SYS;
rec->evlist = evlist__new();
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 923c0fb151222..68f45e9e63b6e 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -617,13 +617,13 @@ struct map *thread__find_map(struct thread *thread, u8 cpumode, u64 addr,
if (cpumode == PERF_RECORD_MISC_KERNEL && perf_host) {
al->level = 'k';
maps = machine__kernel_maps(machine);
- load_map = true;
+ load_map = !symbol_conf.lazy_load_kernel_maps;
} else if (cpumode == PERF_RECORD_MISC_USER && perf_host) {
al->level = '.';
} else if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL && perf_guest) {
al->level = 'g';
maps = machine__kernel_maps(machine);
- load_map = true;
+ load_map = !symbol_conf.lazy_load_kernel_maps;
} else if (cpumode == PERF_RECORD_MISC_GUEST_USER && perf_guest) {
al->level = 'u';
} else {
diff --git a/tools/perf/util/symbol_conf.h b/tools/perf/util/symbol_conf.h
index 0b589570d1d09..2b2fb9e224b00 100644
--- a/tools/perf/util/symbol_conf.h
+++ b/tools/perf/util/symbol_conf.h
@@ -42,7 +42,8 @@ struct symbol_conf {
inline_name,
disable_add2line_warn,
buildid_mmap2,
- guest_code;
+ guest_code,
+ lazy_load_kernel_maps;
const char *vmlinux_name,
*kallsyms_name,
*source_prefix,
