From 7adc363bc29e6c336969091af57d45d1d9619322 Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Thu, 2 Nov 2023 10:56:44 -0700 Subject: 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 Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Alexander Shishkin Cc: Andi Kleen Cc: Athira Jajeev Cc: Changbin Du Cc: Colin Ian King Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: German Gomez Cc: Huacai Chen Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: K Prateek Nayak Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Li Dong Cc: Liam Howlett Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Miguel Ojeda Cc: Ming Wang Cc: Nick Terrell Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Sandipan Das Cc: Sean Christopherson Cc: Steinar H. Gunderson Cc: Vincent Whitchurch Cc: Wenyu Liu Cc: Yang Jihong Link: https://lore.kernel.org/r/20231102175735.2272696-3-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo Stable-dep-of: aaf494cf483a ("perf annotate: Fix annotation_calc_lines() to pass correct address to get_srcline()") Signed-off-by: Sasha Levin --- tools/perf/builtin-inject.c | 6 ++++++ tools/perf/builtin-record.c | 2 ++ tools/perf/util/event.c | 4 ++-- tools/perf/util/symbol_conf.h | 3 ++- 4 files changed, 12 insertions(+), 3 deletions(-) (limited to 'tools/perf') diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c index c8cf2fdd9cff..eb3ef5c24b66 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 []", 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 ea80bf4dc434..5c54fda63b58 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 923c0fb15122..68f45e9e63b6 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 0b589570d1d0..2b2fb9e224b0 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, -- cgit v1.2.3