From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B09EC28CBC for ; Wed, 6 May 2020 15:27:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 661DB2068E for ; Wed, 6 May 2020 15:27:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588778859; bh=6VL1jyARxbluo0/AT4ri3QbZDHzDnA1PTlrdegkKUVo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=afPMSLK83lr0vY++Mm39prX0oH4X78+hKOK/ehBKVelnDQMEs52ESweniqpnqnFPK V6W91KsRmqmcXVrG4Eh7QtsJAA0lxT2IFabx703fFOOCnTKG/QP1HKIDMfI931Yhqv PizTtG7FEet3C+bUkjFnY++ZchQUmSUNU7AdU1CM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730364AbgEFP1i (ORCPT ); Wed, 6 May 2020 11:27:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:51674 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729683AbgEFP1f (ORCPT ); Wed, 6 May 2020 11:27:35 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 20FA521582; Wed, 6 May 2020 15:27:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588778854; bh=6VL1jyARxbluo0/AT4ri3QbZDHzDnA1PTlrdegkKUVo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lo8F1tROAkhGdvDlujCNpJ+uyNGE+cqP1VY2D6fu3MJd4wGswitRI9iWN+7RUn35P yz3g0igT33h4vncPHnwxllJEOj3lalwCcNEUPRBSc+hVekB3BpSQ9xT2xUO4TRvNsA /jll7+/sxQ4LKTiFkcO0gUjmbkYb9cQy0e3d8HH4= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Ian Rogers , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Mark Rutland , Peter Zijlstra , Stephane Eranian Subject: [PATCH 88/91] libsymbols kallsyms: Parse using io api Date: Wed, 6 May 2020 12:22:31 -0300 Message-Id: <20200506152234.21977-89-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200506152234.21977-1-acme@kernel.org> References: <20200506152234.21977-1-acme@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ian Rogers 'perf record' will call kallsyms__parse 4 times during startup and process megabytes of data. This changes kallsyms__parse to use the io library rather than fgets to improve performance of the user code by over 8%. Before: Running 'internals/kallsyms-parse' benchmark: Average kallsyms__parse took: 103.988 ms (+- 0.203 ms) After: Running 'internals/kallsyms-parse' benchmark: Average kallsyms__parse took: 95.571 ms (+- 0.006 ms) For a workload like: $ perf record /bin/true Run under 'perf record -e cycles:u -g' the time goes from: Before 30.10% 1.67% perf perf [.] kallsyms__parse After 25.55% 20.04% perf perf [.] kallsyms__parse So a little under 5% of the start-up time is removed. A lot of what remains is on the kernel side, but caching kallsyms within perf would at least impact memory footprint. Committer notes: The internal/kallsyms-parse bench is run using: [root@five ~]# perf bench internals kallsyms-parse # Running 'internals/kallsyms-parse' benchmark: Average kallsyms__parse took: 80.381 ms (+- 0.115 ms) [root@five ~]# And this pre-existing test uses these routines to parse kallsyms and then compare with the info obtained from the matching ELF symtab: [root@five ~]# perf test vmlinux 1: vmlinux symtab matches kallsyms : Ok [root@five ~]# Also we can't remove hex2u64() in this patch as this breaks the build: /usr/bin/ld: /tmp/build/perf/perf-in.o: in function `modules__parse': /home/acme/git/perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64' /usr/bin/ld: /home/acme/git/perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64' /usr/bin/ld: /tmp/build/perf/perf-in.o: in function `dso__load_perf_map': /home/acme/git/perf/tools/perf/util/symbol.c:1477: undefined reference to `hex2u64' /usr/bin/ld: /home/acme/git/perf/tools/perf/util/symbol.c:1483: undefined reference to `hex2u64' collect2: error: ld returned 1 exit status Leave it there, move it in the next patch. Signed-off-by: Ian Rogers Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Link: http://lore.kernel.org/lkml/20200501221315.54715-3-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/api/io.h | 3 ++ tools/lib/symbol/kallsyms.c | 93 +++++++++++++++++++------------------ 2 files changed, 51 insertions(+), 45 deletions(-) diff --git a/tools/lib/api/io.h b/tools/lib/api/io.h index b7e55b5f8a4a..777c20f6b604 100644 --- a/tools/lib/api/io.h +++ b/tools/lib/api/io.h @@ -7,6 +7,9 @@ #ifndef __API_IO__ #define __API_IO__ +#include +#include + struct io { /* File descriptor being read/ */ int fd; diff --git a/tools/lib/symbol/kallsyms.c b/tools/lib/symbol/kallsyms.c index 1a7a9f877095..a5edc75c346c 100644 --- a/tools/lib/symbol/kallsyms.c +++ b/tools/lib/symbol/kallsyms.c @@ -1,7 +1,9 @@ // SPDX-License-Identifier: GPL-2.0 #include "symbol/kallsyms.h" +#include "api/io.h" #include -#include +#include +#include u8 kallsyms2elf_type(char type) { @@ -9,12 +11,6 @@ u8 kallsyms2elf_type(char type) return (type == 't' || type == 'w') ? STT_FUNC : STT_OBJECT; } -bool kallsyms__is_function(char symbol_type) -{ - symbol_type = toupper(symbol_type); - return symbol_type == 'T' || symbol_type == 'W'; -} - /* * While we find nice hex chars, build a long_val. * Return number of chars processed. @@ -28,61 +24,68 @@ int hex2u64(const char *ptr, u64 *long_val) return p - ptr; } +bool kallsyms__is_function(char symbol_type) +{ + symbol_type = toupper(symbol_type); + return symbol_type == 'T' || symbol_type == 'W'; +} + +static void read_to_eol(struct io *io) +{ + int ch; + + for (;;) { + ch = io__get_char(io); + if (ch < 0 || ch == '\n') + return; + } +} + int kallsyms__parse(const char *filename, void *arg, int (*process_symbol)(void *arg, const char *name, char type, u64 start)) { - char *line = NULL; - size_t n; - int err = -1; - FILE *file = fopen(filename, "r"); - - if (file == NULL) - goto out_failure; - - err = 0; + struct io io; + char bf[BUFSIZ]; + int err; - while (!feof(file)) { - u64 start; - int line_len, len; - char symbol_type; - char *symbol_name; + io.fd = open(filename, O_RDONLY, 0); - line_len = getline(&line, &n, file); - if (line_len < 0 || !line) - break; + if (io.fd < 0) + return -1; - line[--line_len] = '\0'; /* \n */ + io__init(&io, io.fd, bf, sizeof(bf)); - len = hex2u64(line, &start); + err = 0; + while (!io.eof) { + __u64 start; + int ch; + size_t i; + char symbol_type; + char symbol_name[KSYM_NAME_LEN + 1]; - /* Skip the line if we failed to parse the address. */ - if (!len) + if (io__get_hex(&io, &start) != ' ') { + read_to_eol(&io); continue; - - len++; - if (len + 2 >= line_len) + } + symbol_type = io__get_char(&io); + if (io__get_char(&io) != ' ') { + read_to_eol(&io); continue; - - symbol_type = line[len]; - len += 2; - symbol_name = line + len; - len = line_len - len; - - if (len >= KSYM_NAME_LEN) { - err = -1; - break; } + for (i = 0; i < sizeof(symbol_name); i++) { + ch = io__get_char(&io); + if (ch < 0 || ch == '\n') + break; + symbol_name[i] = ch; + } + symbol_name[i] = '\0'; err = process_symbol(arg, symbol_name, symbol_type, start); if (err) break; } - free(line); - fclose(file); + close(io.fd); return err; - -out_failure: - return -1; } -- 2.21.1