From: Steven Rostedt <rostedt@goodmis.org>
To: Yinan Liu <yinan@linux.alibaba.com>
Cc: peterz@infradead.org, mark-pk.tsai@mediatek.com,
mingo@redhat.com, linux-kernel@vger.kernel.org,
Masami Hiramatsu <mhiramat@kernel.org>
Subject: Re: [PATCH v6 1/2] scripts: ftrace - move the sort-processing in ftrace_init
Date: Thu, 2 Dec 2021 12:58:00 -0500 [thread overview]
Message-ID: <20211202125800.7b346733@gandalf.local.home> (raw)
In-Reply-To: <20211202021606.48812-2-yinan@linux.alibaba.com>
[-- Attachment #1: Type: text/plain, Size: 10865 bytes --]
On Thu, 2 Dec 2021 10:16:05 +0800
Yinan Liu <yinan@linux.alibaba.com> wrote:
> 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.
>
> Signed-off-by: Yinan Liu <yinan@linux.alibaba.com>
> Reported-by: kernel test robot <lkp@intel.com>
After applying this, I get a failure on the kprobe self tests at boot up:
Testing ftrace filter: OK
trace_kprobe: Testing kprobe tracing:
trace_kprobe: Could not probe notrace function kprobe_trace_selftest_target
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1 at kernel/trace/trace_kprobe.c:1973 kprobe_trace_self_tests_init+0x5c/0x497
Modules linked in:
CPU: 2 PID: 1 Comm: swapper/0 Tainted: G W 5.16.0-rc3-test+ #40
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
RIP: 0010:kprobe_trace_self_tests_init+0x5c/0x497
Code: 5f d7 94 ff 00 0f 85 48 04 00 00 48 c7 c7 c0 ff 8e 88 e8 6b bb cd fd 48 c7 c7 20 00 8f 88 e8 a9 b6 db fc 41 89 c4 85 c0 74 16 <0f> 0b 48 c7 c7 a0 00 8f 88 41 bc 01 00 00 00 e8 44 bb cd fd eb 33
RSP: 0000:ffffc90000037d00 EFLAGS: 00010282
RAX: 00000000ffffffea RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880c2b33eb4
RBP: 1ffff92000006fa9 R08: ffffffff872e1900 R09: 0000000080000171
R10: fffff52000006f15 R11: 0000000000000001 R12: 00000000ffffffea
R13: 0000000000000007 R14: ffffffff8a608098 R15: ffffffff8a6080a0
FS: 0000000000000000(0000) GS:ffff8880c2b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000009260e001 CR4: 00000000001706e0
Call Trace:
<TASK>
? init_kprobe_trace+0x1c4/0x1c4
do_one_initcall+0x89/0x2b0
? trace_event_raw_event_initcall_finish+0x150/0x150
? parameq+0x90/0x90
? _raw_spin_unlock_irqrestore+0x19/0x40
kernel_init_freeable+0x35a/0x3e7
? console_on_rootfs+0x52/0x52
? _raw_spin_unlock+0x30/0x30
? rest_init+0xf0/0xf0
? rest_init+0xf0/0xf0
kernel_init+0x19/0x140
ret_from_fork+0x22/0x30
</TASK>
---[ end trace 27c06839fac37d16 ]---
Config attached.
-- Steve
> ---
> kernel/trace/ftrace.c | 11 +++-
> scripts/Makefile | 2 +-
> scripts/link-vmlinux.sh | 6 +-
> scripts/sorttable.c | 2 +
> scripts/sorttable.h | 120 +++++++++++++++++++++++++++++++++++++++-
> 5 files changed, 133 insertions(+), 8 deletions(-)
>
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 7b180f61e6d3..c0f95cae68b5 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -6189,8 +6189,15 @@ 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)
> diff --git a/scripts/Makefile b/scripts/Makefile
> index 9adb6d247818..b286e112e3b0 100644
> --- a/scripts/Makefile
> +++ b/scripts/Makefile
> @@ -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 = $(CRYPTO_LIBS)
> @@ -29,7 +30,6 @@ ARCH := x86
> endif
> HOSTCFLAGS_sorttable.o += -I$(srctree)/tools/arch/x86/include
> HOSTCFLAGS_sorttable.o += -DUNWINDER_ORC_ENABLED
> -HOSTLDLIBS_sorttable = -lpthread
> endif
>
> # The following programs are only built on demand
> diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
> index 36ef7b37fc5d..e2e1a8f39f15 100755
> --- a/scripts/link-vmlinux.sh
> +++ b/scripts/link-vmlinux.sh
> @@ -422,6 +422,9 @@ 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
> @@ -430,9 +433,6 @@ 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
> diff --git a/scripts/sorttable.c b/scripts/sorttable.c
> index 0ef3abfc4a51..11a595ca256b 100644
> --- a/scripts/sorttable.c
> +++ b/scripts/sorttable.c
> @@ -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>
> diff --git a/scripts/sorttable.h b/scripts/sorttable.h
> index a2baa2fefb13..a7a5b8078954 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 CONFIG_FUNCTION_TRACER
> +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 CONFIG_FUNCTION_TRACER
> + 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 CONFIG_FUNCTION_TRACER
> + /* 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 CONFIG_FUNCTION_TRACER
> + 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 CONFIG_FUNCTION_TRACER
> + 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;
> }
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 37215 bytes --]
next prev parent reply other threads:[~2021-12-02 17:58 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-11 13:50 [PATCH 0/2] ftrace: improve ftrace during compiling Yinan Liu
2021-09-11 13:50 ` [PATCH 1/2] scripts: ftrace - move the sort-processing in ftrace_init to compile time Yinan Liu
2021-09-11 13:59 ` Steven Rostedt
2021-10-03 13:42 ` Yinan Liu
2021-10-08 23:48 ` Steven Rostedt
2021-10-09 2:56 ` Yinan Liu
2021-10-25 13:20 ` Yinan Liu
2021-10-25 15:00 ` Steven Rostedt
2021-09-11 13:50 ` [PATCH 2/2] scripts: ftrace - move the nop-processing " Yinan Liu
2021-09-11 14:12 ` Steven Rostedt
2021-09-11 15:28 ` Yinan Liu
2021-09-11 16:07 ` Peter Zijlstra
2021-09-11 14:33 ` Peter Zijlstra
2021-09-11 17:15 ` kernel test robot
2021-09-11 17:15 ` kernel test robot
2021-09-11 18:04 ` kernel test robot
2021-09-11 18:04 ` kernel test robot
2021-11-16 2:49 ` [PATCH v2 0/2] ftrace optimization at " Yinan Liu
2021-11-16 2:49 ` [PATCH v2 1/2] scripts: ftrace - move the sort-processing in ftrace_init to " Yinan Liu
2021-11-16 8:07 ` Peter Zijlstra
2021-11-16 12:42 ` Yinan Liu
2021-11-16 13:05 ` Peter Zijlstra
2021-11-16 14:46 ` Yinan Liu
2021-11-17 13:34 ` kernel test robot
2021-11-17 13:34 ` kernel test robot
2021-11-16 2:49 ` [PATCH v2 2/2] scripts: ftrace - move the nop-processing " Yinan Liu
2021-11-16 8:10 ` Peter Zijlstra
2021-11-16 12:51 ` Yinan Liu
2021-11-16 13:07 ` Steven Rostedt
2021-11-16 15:02 ` Yinan Liu
2021-11-16 16:06 ` Steven Rostedt
2021-11-22 13:43 ` [PATCH v3] scripts: ftrace - move the sort-processing " Yinan Liu
2021-11-23 10:54 ` [PATCH v4] ftrace sorting optimization changelog Yinan Liu
2021-11-23 10:54 ` [PATCH v4] scripts: ftrace - move the sort-processing in ftrace_init to compile time Yinan Liu
2021-11-29 2:13 ` Yinan Liu
2021-11-29 3:51 ` Steven Rostedt
2021-11-29 6:52 ` Yinan Liu
2021-11-30 17:08 ` Steven Rostedt
2021-12-01 5:32 ` [PATCH v5 0/2] ftrace sorting optimization changelog Yinan Liu
2021-12-01 5:32 ` [PATCH v5 1/2] scripts: ftrace - move the sort-processing in ftrace_init to compile time Yinan Liu
2021-12-01 21:45 ` Steven Rostedt
2021-12-05 12:35 ` [scripts] 12955fb1c5: kernel-selftests.livepatch.test-ftrace.sh.fail kernel test robot
2021-12-05 12:35 ` kernel test robot
2021-12-01 5:32 ` [PATCH v5 2/2] script/sorttable: code style improvements Yinan Liu
2021-12-02 2:16 ` [PATCH v6 0/2] ftrace sorting optimization changelog Yinan Liu
2021-12-02 2:16 ` [PATCH v6 1/2] scripts: ftrace - move the sort-processing in ftrace_init Yinan Liu
2021-12-02 17:58 ` Steven Rostedt [this message]
2021-12-05 12:45 ` Masami Hiramatsu
2021-12-06 20:18 ` Steven Rostedt
2021-12-07 1:29 ` Yinan Liu
2021-12-02 2:16 ` [PATCH v6 2/2] script/sorttable: code style improvements Yinan Liu
2021-12-02 15:30 ` [PATCH v6 0/2] ftrace sorting optimization changelog Peter Zijlstra
2021-12-07 15:13 ` [PATCH v7 0/2] ftrace sorting optimization Yinan Liu
2021-12-07 15:13 ` [PATCH v7 1/2] scripts: ftrace - move the sort-processing in ftrace_init Yinan Liu
2021-12-11 14:50 ` Steven Rostedt
2021-12-07 15:13 ` [PATCH v7 2/2] script/sorttable: code style improvements Yinan Liu
2021-12-12 11:33 ` [PATCH v8 0/1] change log Yinan Liu
2021-12-12 11:33 ` [PATCH v8] scripts: ftrace - move the sort-processing in ftrace_init Yinan Liu
2022-01-21 9:46 ` Sven Schnelle
2022-01-21 10:42 ` Heiko Carstens
2022-01-21 11:14 ` Sven Schnelle
2022-01-21 11:29 ` Sven Schnelle
2022-01-21 18:11 ` Steven Rostedt
2022-01-22 9:17 ` Heiko Carstens
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20211202125800.7b346733@gandalf.local.home \
--to=rostedt@goodmis.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark-pk.tsai@mediatek.com \
--cc=mhiramat@kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=yinan@linux.alibaba.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.