Commit 72b3942a authored by Yinan Liu's avatar Yinan Liu Committed by Steven Rostedt

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.comSigned-off-by: default avatarYinan Liu <yinan@linux.alibaba.com>
Reported-by: default avatarkernel test robot <lkp@intel.com>
Reported-by: default avatarkernel test robot <oliver.sang@intel.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 1c1857d4
......@@ -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)
......
......@@ -17,6 +17,7 @@ hostprogs-always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE) += insert-sys-cert
hostprogs-always-$(CONFIG_SYSTEM_REVOCATION_LIST) += extract-cert
HOSTCFLAGS_sorttable.o = -I$(srctree)/tools/include
HOSTLDLIBS_sorttable = -lpthread
HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include
HOSTCFLAGS_sign-file.o = $(CRYPTO_CFLAGS)
HOSTLDLIBS_sign-file = $(CRYPTO_LIBS)
......@@ -29,7 +30,10 @@ ARCH := x86
endif
HOSTCFLAGS_sorttable.o += -I$(srctree)/tools/arch/x86/include
HOSTCFLAGS_sorttable.o += -DUNWINDER_ORC_ENABLED
HOSTLDLIBS_sorttable = -lpthread
endif
ifdef CONFIG_DYNAMIC_FTRACE
HOSTCFLAGS_sorttable.o += -DMCOUNT_SORT_ENABLED
endif
# The following programs are only built on demand
......
......@@ -400,6 +400,9 @@ if [ -n "${CONFIG_DEBUG_INFO_BTF}" -a -n "${CONFIG_BPF}" ]; then
${RESOLVE_BTFIDS} vmlinux
fi
info SYSMAP System.map
mksysmap vmlinux System.map
if [ -n "${CONFIG_BUILDTIME_TABLE_SORT}" ]; then
info SORTTAB vmlinux
if ! sorttable vmlinux; then
......@@ -408,9 +411,6 @@ if [ -n "${CONFIG_BUILDTIME_TABLE_SORT}" ]; then
fi
fi
info SYSMAP System.map
mksysmap vmlinux System.map
# step a (see comment above)
if [ -n "${CONFIG_KALLSYMS}" ]; then
mksysmap ${kallsyms_vmlinux} .tmp_System.map
......
......@@ -30,6 +30,8 @@
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <pthread.h>
#include <tools/be_byteshift.h>
#include <tools/le_byteshift.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 @@ static int do_sort(Elf_Ehdr *ehdr,
}
}
#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;
}
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