Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EDDCCC433EF for ; Tue, 23 Nov 2021 10:54:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235662AbhKWK5V (ORCPT ); Tue, 23 Nov 2021 05:57:21 -0500 Received: from out30-43.freemail.mail.aliyun.com ([115.124.30.43]:33279 "EHLO out30-43.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234319AbhKWK5Q (ORCPT ); Tue, 23 Nov 2021 05:57:16 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04400;MF=yinan@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0UxvDTNN_1637664845; Received: from localhost.localdomain(mailfrom:yinan@linux.alibaba.com fp:SMTPD_---0UxvDTNN_1637664845) by smtp.aliyun-inc.com(127.0.0.1); Tue, 23 Nov 2021 18:54:06 +0800 From: Yinan Liu To: rostedt@goodmis.org, peterz@infradead.org Cc: mark-pk.tsai@mediatek.com, mingo@redhat.com, linux-kernel@vger.kernel.org Subject: [PATCH v4] scripts: ftrace - move the sort-processing in ftrace_init to compile time Date: Tue, 23 Nov 2021 18:54:04 +0800 Message-Id: <20211123105404.22166-2-yinan@linux.alibaba.com> X-Mailer: git-send-email 2.30.1 (Apple Git-130) In-Reply-To: <20211123105404.22166-1-yinan@linux.alibaba.com> References: <20210911135043.16014-1-yinan@linux.alibaba.com> <20211123105404.22166-1-yinan@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Reported-by: kernel test robot --- kernel/trace/ftrace.c | 6 ++- scripts/Makefile | 2 +- scripts/link-vmlinux.sh | 6 +-- scripts/sorttable.c | 2 + scripts/sorttable.h | 113 ++++++++++++++++++++++++++++++++++++++++++++++-- 5 files changed, 119 insertions(+), 10 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 7b180f6..f5af419 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6189,8 +6189,10 @@ static int ftrace_process_locs(struct module *mod, if (!count) return 0; - sort(start, count, sizeof(*start), - ftrace_cmp_ips, NULL); + if (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 9adb6d2..b286e11 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 36ef7b3..e2e1a8f 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 0ef3abf..11a595c 100644 --- a/scripts/sorttable.c +++ b/scripts/sorttable.c @@ -30,6 +30,8 @@ #include #include #include +#include +#include #include #include diff --git a/scripts/sorttable.h b/scripts/sorttable.h index a2baa2f..81dbf37 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 -#include #include #define ERRSTR_MAXSZ 256 @@ -191,6 +198,62 @@ static int compare_extable(const void *a, const void *b) return 1; return 0; } +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); +} static int do_sort(Elf_Ehdr *ehdr, char const *const fname, @@ -217,6 +280,10 @@ static int do_sort(Elf_Ehdr *ehdr, int idx; unsigned int shnum; unsigned int shstrndx; + struct elf_mcount_loc mstruct; + uint_t _start_mcount_loc = 0; + uint_t _stop_mcount_loc = 0; + pthread_t mcount_sort_thread; #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED) unsigned int orc_ip_size = 0; unsigned int orc_size = 0; @@ -253,6 +320,14 @@ static int do_sort(Elf_Ehdr *ehdr, symtab_shndx = (Elf32_Word *)((const char *)ehdr + _r(&s->sh_offset)); + /* 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; + } #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED) /* locate the ORC unwind tables */ if (!strcmp(secstrings + idx, ".orc_unwind_ip")) { @@ -294,6 +369,21 @@ static int do_sort(Elf_Ehdr *ehdr, goto out; } #endif + 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; + } + if (!extab_sec) { fprintf(stderr, "no __ex_table in file: %s\n", fname); goto out; @@ -364,11 +454,11 @@ static int do_sort(Elf_Ehdr *ehdr, void *retval = NULL; /* wait for ORC tables sort done */ rc = pthread_join(orc_sort_thread, &retval); - if (rc) + if (rc) { fprintf(stderr, "pthread_join failed '%s': %s\n", strerror(errno), fname); - else if (retval) { + } else if (retval) { rc = -1; fprintf(stderr, "failed to sort ORC tables '%s': %s\n", @@ -376,5 +466,20 @@ static int do_sort(Elf_Ehdr *ehdr, } } #endif + 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); + } + } return rc; } -- 1.8.3.1