From patchwork Sat Mar 9 17:23:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tom Tromey X-Patchwork-Id: 31803 Received: (qmail 29510 invoked by alias); 9 Mar 2019 17:23:08 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 29361 invoked by uid 89); 9 Mar 2019 17:23:08 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-22.0 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_HELO_PASS autolearn=ham version=3.3.1 spammy=53, 7, 20190303, distributed X-HELO: gateway34.websitewelcome.com Received: from gateway34.websitewelcome.com (HELO gateway34.websitewelcome.com) (192.185.148.212) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Sat, 09 Mar 2019 17:23:05 +0000 Received: from cm12.websitewelcome.com (cm12.websitewelcome.com [100.42.49.8]) by gateway34.websitewelcome.com (Postfix) with ESMTP id 4FF2E16FD73 for ; Sat, 9 Mar 2019 11:23:04 -0600 (CST) Received: from box5379.bluehost.com ([162.241.216.53]) by cmsmtp with SMTP id 2fgehdeLFiQer2fgehoLyi; Sat, 09 Mar 2019 11:23:04 -0600 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tromey.com; s=default; h=References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Sender:Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=ElvBQBRv0M7RnuUNC7ySk16dDZe2oRP7iyUjRRqJzM0=; b=iMrsfqT+WyaYE+0ykunkpTthgH m1JjTYPcKaUfICpAvHY44ofWB7PUdJmr+LptlF2nUCfGlAayNO1wZL0NYOcx3VuKfpC2PUP++c5p7 hUshnGuigs/5m7bT+jZSo+AA2; Received: from 75-166-85-218.hlrn.qwest.net ([75.166.85.218]:56494 helo=bapiya.Home) by box5379.bluehost.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91) (envelope-from ) id 1h2fge-003et2-2T; Sat, 09 Mar 2019 11:23:04 -0600 From: Tom Tromey To: gdb-patches@sourceware.org Cc: Tom Tromey Subject: [RFC 6/6] Demangle minsyms in parallel Date: Sat, 9 Mar 2019 10:23:00 -0700 Message-Id: <20190309172300.2764-7-tom@tromey.com> In-Reply-To: <20190309172300.2764-1-tom@tromey.com> References: <20190309172300.2764-1-tom@tromey.com> This patch introduces a simple parallel for_each and changes the minimal symbol reader to use it when computing the demangled name for a minimal symbol. This yields a speedup when reading minimal symbols. 2019-03-03 Tom Tromey * minsyms.c (minimal_symbol_reader::install): Use parallel_for_each. * common/parallel-for.h: New file. * Makefile.in (HFILES_NO_SRCDIR): Add common/parallel-for.h. --- gdb/ChangeLog | 7 ++++ gdb/Makefile.in | 1 + gdb/common/parallel-for.h | 69 +++++++++++++++++++++++++++++++++++++++ gdb/minsyms.c | 23 +++++++------ 4 files changed, 90 insertions(+), 10 deletions(-) create mode 100644 gdb/common/parallel-for.h diff --git a/gdb/Makefile.in b/gdb/Makefile.in index 5614cc3386c..fec9c4a505c 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -1466,6 +1466,7 @@ HFILES_NO_SRCDIR = \ common/common-inferior.h \ common/netstuff.h \ common/host-defs.h \ + common/parallel-for.h \ common/pathstuff.h \ common/print-utils.h \ common/ptid.h \ diff --git a/gdb/common/parallel-for.h b/gdb/common/parallel-for.h new file mode 100644 index 00000000000..a0ae7bebd16 --- /dev/null +++ b/gdb/common/parallel-for.h @@ -0,0 +1,69 @@ +/* Parallel for loops + + Copyright (C) 2019 Free Software Foundation, Inc. + + This file is part of GDB. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#ifndef COMMON_PARALLEL_FOR_H +#define COMMON_PARALLEL_FOR_H + +#include +#include + +namespace gdb +{ + +/* A very simple "parallel for". This iterates over the elements + given by the range of iterators, which must be random access + iterators. For each element, it calls the callback function. The + work may or may not be done by separate threads. */ + +template +void parallel_for_each (RandomIt first, RandomIt last, UnaryFunction f) +{ + unsigned n_threads = std::thread::hardware_concurrency (); + /* So we can use a local array below. */ + const unsigned max_threads = 16; + if (n_threads > max_threads) + n_threads = max_threads; + + if (n_threads == 0 || last - first < 2 * n_threads) + { + /* Don't bother. */ + std::for_each (first, last, f); + return; + } + + auto body = [&] (RandomIt start) + { + for (; start < last; start += n_threads) + f (*start); + }; + + std::thread threads[max_threads]; + for (unsigned i = 0; i < n_threads; ++i) + { + threads[i] = std::thread (body, first); + ++first; + } + + for (unsigned i = 0; i < n_threads; ++i) + threads[i].join (); +} + +} + +#endif /* COMMON_PARALLEL_FOR_H */ diff --git a/gdb/minsyms.c b/gdb/minsyms.c index 7872b7e2588..75c1bb9daf4 100644 --- a/gdb/minsyms.c +++ b/gdb/minsyms.c @@ -53,6 +53,7 @@ #include "common/symbol.h" #include #include "safe-ctype.h" +#include "common/parallel-for.h" /* See minsyms.h. */ @@ -1409,16 +1410,18 @@ minimal_symbol_reader::install () m_objfile->per_bfd->msymbols = std::move (msym_holder); msymbols = m_objfile->per_bfd->msymbols.get (); - for (int i = 0; i < mcount; ++i) - { - if (!msymbols[i].name_set) - { - symbol_set_names (&msymbols[i], msymbols[i].name, - strlen (msymbols[i].name), 0, - m_objfile->per_bfd); - msymbols[i].name_set = 1; - } - } + gdb::parallel_for_each + (&msymbols[0], &msymbols[mcount], + [&] (minimal_symbol &msym) + { + if (!msym.name_set) + { + symbol_set_names (&msym, msym.name, + strlen (msym.name), 0, + m_objfile->per_bfd); + msym.name_set = 1; + } + }); /* Now build the hash tables; we can't do this incrementally at an earlier point since we weren't finished with the obstack