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authorYinan Liu <yinan@linux.alibaba.com>2021-12-12 19:33:58 +0800
committerSteven Rostedt <rostedt@goodmis.org>2022-01-13 16:23:04 -0500
commit72b3942a173c387b27860ba1069636726e208777 (patch)
treef5c9e5f29af4aeae0dbaf9d7232dd985cc5cf4b3 /scripts/sorttable.h
parent1c1857d400355e96f0fe8b32adc6fa7594d03b52 (diff)
downloadlinux-72b3942a173c387b27860ba1069636726e208777.tar.bz2
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 'scripts/sorttable.h')
-rw-r--r--scripts/sorttable.h120
1 files changed, 118 insertions, 2 deletions
diff --git a/scripts/sorttable.h b/scripts/sorttable.h
index 7b9745cf8c70..1e8b77928fa4 100644
--- a/scripts/sorttable.h
+++ b/scripts/sorttable.h
@@ -19,6 +19,9 @@
#undef extable_ent_size
#undef compare_extable
+#undef get_mcount_loc
+#undef sort_mcount_loc
+#undef elf_mcount_loc
#undef do_sort
#undef Elf_Addr
#undef Elf_Ehdr
@@ -41,6 +44,9 @@
#ifdef SORTTABLE_64
# define extable_ent_size 16
# define compare_extable compare_extable_64
+# define get_mcount_loc get_mcount_loc_64
+# define sort_mcount_loc sort_mcount_loc_64
+# define elf_mcount_loc elf_mcount_loc_64
# define do_sort do_sort_64
# define Elf_Addr Elf64_Addr
# define Elf_Ehdr Elf64_Ehdr
@@ -62,6 +68,9 @@
#else
# define extable_ent_size 8
# define compare_extable compare_extable_32
+# define get_mcount_loc get_mcount_loc_32
+# define sort_mcount_loc sort_mcount_loc_32
+# define elf_mcount_loc elf_mcount_loc_32
# define do_sort do_sort_32
# define Elf_Addr Elf32_Addr
# define Elf_Ehdr Elf32_Ehdr
@@ -84,8 +93,6 @@
#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
/* ORC unwinder only support X86_64 */
-#include <errno.h>
-#include <pthread.h>
#include <asm/orc_types.h>
#define ERRSTR_MAXSZ 256
@@ -191,7 +198,64 @@ static int compare_extable(const void *a, const void *b)
return 1;
return 0;
}
+#ifdef MCOUNT_SORT_ENABLED
+struct elf_mcount_loc {
+ Elf_Ehdr *ehdr;
+ Elf_Shdr *init_data_sec;
+ uint_t start_mcount_loc;
+ uint_t stop_mcount_loc;
+};
+
+/* Sort the addresses stored between __start_mcount_loc to __stop_mcount_loc in vmlinux */
+static void *sort_mcount_loc(void *arg)
+{
+ struct elf_mcount_loc *emloc = (struct elf_mcount_loc *)arg;
+ uint_t offset = emloc->start_mcount_loc - _r(&(emloc->init_data_sec)->sh_addr)
+ + _r(&(emloc->init_data_sec)->sh_offset);
+ uint_t count = emloc->stop_mcount_loc - emloc->start_mcount_loc;
+ unsigned char *start_loc = (void *)emloc->ehdr + offset;
+
+ qsort(start_loc, count/sizeof(uint_t), sizeof(uint_t), compare_extable);
+ return NULL;
+}
+
+/* Get the address of __start_mcount_loc and __stop_mcount_loc in System.map */
+static void get_mcount_loc(uint_t *_start, uint_t *_stop)
+{
+ FILE *file_start, *file_stop;
+ char start_buff[20];
+ char stop_buff[20];
+ int len = 0;
+
+ file_start = popen(" grep start_mcount System.map | awk '{print $1}' ", "r");
+ if (!file_start) {
+ fprintf(stderr, "get start_mcount_loc error!");
+ return;
+ }
+
+ file_stop = popen(" grep stop_mcount System.map | awk '{print $1}' ", "r");
+ if (!file_stop) {
+ fprintf(stderr, "get stop_mcount_loc error!");
+ pclose(file_start);
+ return;
+ }
+
+ while (fgets(start_buff, sizeof(start_buff), file_start) != NULL) {
+ len = strlen(start_buff);
+ start_buff[len - 1] = '\0';
+ }
+ *_start = strtoul(start_buff, NULL, 16);
+
+ while (fgets(stop_buff, sizeof(stop_buff), file_stop) != NULL) {
+ len = strlen(stop_buff);
+ stop_buff[len - 1] = '\0';
+ }
+ *_stop = strtoul(stop_buff, NULL, 16);
+ pclose(file_start);
+ pclose(file_stop);
+}
+#endif
static int do_sort(Elf_Ehdr *ehdr,
char const *const fname,
table_sort_t custom_sort)
@@ -217,6 +281,12 @@ static int do_sort(Elf_Ehdr *ehdr,
int idx;
unsigned int shnum;
unsigned int shstrndx;
+#ifdef MCOUNT_SORT_ENABLED
+ struct elf_mcount_loc mstruct;
+ uint_t _start_mcount_loc = 0;
+ uint_t _stop_mcount_loc = 0;
+ pthread_t mcount_sort_thread;
+#endif
#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
unsigned int orc_ip_size = 0;
unsigned int orc_size = 0;
@@ -253,6 +323,17 @@ static int do_sort(Elf_Ehdr *ehdr,
symtab_shndx = (Elf32_Word *)((const char *)ehdr +
_r(&s->sh_offset));
+#ifdef MCOUNT_SORT_ENABLED
+ /* locate the .init.data section in vmlinux */
+ if (!strcmp(secstrings + idx, ".init.data")) {
+ get_mcount_loc(&_start_mcount_loc, &_stop_mcount_loc);
+ mstruct.ehdr = ehdr;
+ mstruct.init_data_sec = s;
+ mstruct.start_mcount_loc = _start_mcount_loc;
+ mstruct.stop_mcount_loc = _stop_mcount_loc;
+ }
+#endif
+
#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
/* locate the ORC unwind tables */
if (!strcmp(secstrings + idx, ".orc_unwind_ip")) {
@@ -294,6 +375,23 @@ static int do_sort(Elf_Ehdr *ehdr,
goto out;
}
#endif
+
+#ifdef MCOUNT_SORT_ENABLED
+ if (!mstruct.init_data_sec || !_start_mcount_loc || !_stop_mcount_loc) {
+ fprintf(stderr,
+ "incomplete mcount's sort in file: %s\n",
+ fname);
+ goto out;
+ }
+
+ /* create thread to sort mcount_loc concurrently */
+ if (pthread_create(&mcount_sort_thread, NULL, &sort_mcount_loc, &mstruct)) {
+ fprintf(stderr,
+ "pthread_create mcount_sort_thread failed '%s': %s\n",
+ strerror(errno), fname);
+ goto out;
+ }
+#endif
if (!extab_sec) {
fprintf(stderr, "no __ex_table in file: %s\n", fname);
goto out;
@@ -376,5 +474,23 @@ out:
}
}
#endif
+
+#ifdef MCOUNT_SORT_ENABLED
+ if (mcount_sort_thread) {
+ void *retval = NULL;
+ /* wait for mcount sort done */
+ rc = pthread_join(mcount_sort_thread, &retval);
+ if (rc) {
+ fprintf(stderr,
+ "pthread_join failed '%s': %s\n",
+ strerror(errno), fname);
+ } else if (retval) {
+ rc = -1;
+ fprintf(stderr,
+ "failed to sort mcount '%s': %s\n",
+ (char *)retval, fname);
+ }
+ }
+#endif
return rc;
}