diff options
| author |   Yinan Liu <yinan@linux.alibaba.com> | 2021-12-12 19:33:58 +0800 |
|---|---|---|
| committer |   Steven Rostedt <rostedt@goodmis.org> | 2022-01-13 16:23:04 -0500 |
| commit | 72b3942a173c387b27860ba1069636726e208777 (patch) | |
| tree | f5c9e5f29af4aeae0dbaf9d7232dd985cc5cf4b3 /kernel | |
| parent | tracing/probes: check the return value of kstrndup() for pbuf (diff) | |
| download | linux-dev-72b3942a173c387b27860ba1069636726e208777.tar.xz linux-dev-72b3942a173c387b27860ba1069636726e208777.zip | |
scripts: ftrace - move the sort-processing in ftrace_init
When the kernel starts, the initialization of ftrace takes
up a portion of the time (approximately 6~8ms) to sort mcount
addresses. We can save this time by moving mcount-sorting to
compile time.
Link: https://lkml.kernel.org/r/20211212113358.34208-2-yinan@linux.alibaba.com
Signed-off-by: Yinan Liu <yinan@linux.alibaba.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ftrace.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 30bc880c3849..9ca63df6553a 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6406,8 +6406,15 @@ static int ftrace_process_locs(struct module *mod, if (!count) return 0; - sort(start, count, sizeof(*start), - ftrace_cmp_ips, NULL); + /* + * Sorting mcount in vmlinux at build time depend on + * CONFIG_BUILDTIME_TABLE_SORT, while mcount loc in + * modules can not be sorted at build time. + */ + if (!IS_ENABLED(CONFIG_BUILDTIME_TABLE_SORT) || mod) { + sort(start, count, sizeof(*start), + ftrace_cmp_ips, NULL); + } start_pg = ftrace_allocate_pages(count); if (!start_pg) |