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=-13.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=no 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 85705C433B4 for ; Sat, 1 May 2021 00:25:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 57D6D61423 for ; Sat, 1 May 2021 00:25:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231392AbhEAA0G (ORCPT ); Fri, 30 Apr 2021 20:26:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37236 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230298AbhEAA0E (ORCPT ); Fri, 30 Apr 2021 20:26:04 -0400 Received: from mail-lf1-x131.google.com (mail-lf1-x131.google.com [IPv6:2a00:1450:4864:20::131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5FC4EC06174A for ; Fri, 30 Apr 2021 17:25:15 -0700 (PDT) Received: by mail-lf1-x131.google.com with SMTP id j10so19545269lfb.12 for ; Fri, 30 Apr 2021 17:25:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=nUs/JERTrW3HUrDL/wVgoAkdrrpfaLfIyhV+eubJz2w=; b=ovfeJotqKRsfWrPIH6AIxi/XyxgV6ULfCeDnbzlEglpH+gp/04eFGbHmqgeptZTVki +cRjF3KDoiPmfsOylvLmq9YJ+5oVUtZezoVdzJQRGmHbiHOr5+mcn/S9yT+yZkGYkOVQ 40grV2eLwoILokTAGYdmPUS19V78mI8XFkXWyvWBqM4B4PBTl3cxTyy83t9WHv7BFKlT pxsqNAvzWLJ2uqb98WFaSSM6BmSN8Q65f+C6HBk6/XeCYl3vSbJmmrw7AQUu4IXHpub+ acTOcakDRFyCPDtvu50Db9IB+E5EteLRCjViFP8rcIQPLPDYI2o5yK5wT7SNJn1gqJtf LoLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=nUs/JERTrW3HUrDL/wVgoAkdrrpfaLfIyhV+eubJz2w=; b=P+PWY8tWNBBnYnIR0H1cfVdIxhWjzx9wfN+sgrkZfPbC1fhQynrJGFFcliiPfVjUva qwgExKKH6S/rDowlkBQ1x/CEUthX+YZ3xADcZbg09EPhqCwsrIYMICrKZ2HDf0F42SBK W20Jeu4wM4PF6ZK8/Y5ep8QXzeaZOQ6LvB2hQ2DtJ78aefpvik5vi0YHs6zaeHLYJvop PkvhYbzvCqajclgDvGhUwZelbrgCZeNZ2pzKEF6r5LHnrSVQTE05g0qTEgY02j5Gvp+X X5+jx3uGeHGwxdJg1xRNBPuxJwLSl9PztlSOK7GLpECb9JHq3kuLm5zZCg0acOfUGlli COmA== X-Gm-Message-State: AOAM530vPOw9Yb/L2EJnJgt/kUTjlxYvNqlNhpJTTVoqSwDPxDLg+wW+ PIufKQZcvte4dZkMJbDqPJCHn16qYnZzjkqzcVXJEA== X-Google-Smtp-Source: ABdhPJwrCGjFzrIGadve5J2FKRLLJTGo55M0OYqu4dLKi7taQ4gue28o+B8PwwPcGzfInNpsLVa4xR4vwG+ra3TmWNI= X-Received: by 2002:a05:6512:94d:: with SMTP id u13mr4794407lft.368.1619828713748; Fri, 30 Apr 2021 17:25:13 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Nick Desaulniers Date: Fri, 30 Apr 2021 17:25:02 -0700 Message-ID: Subject: Re: Very slow clang kernel config .. To: Linus Torvalds , Masahiro Yamada Cc: Nathan Chancellor , Linux Kernel Mailing List , clang-built-linux Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 30, 2021 at 5:23 PM Nick Desaulniers wrote: > > On Fri, Apr 30, 2021 at 5:19 PM Nick Desaulniers > wrote: > > > > A quick: > > $ perf record -e cycles:pp --call-graph lbr make LLVM=1 LLVM_IAS=1 > > -j72 allmodconfig > > $ perf report --no-children --sort=dso,symbol > > shows: > > 2.35% [unknown] [k] 0xffffffffabc00fc7 > > + 2.29% libc-2.31.so [.] _int_malloc > > 1.24% libc-2.31.so [.] _int_free > > + 1.23% ld-2.31.so [.] do_lookup_x > > ^ bfd > > + 0.63% ld-2.31.so [.] _dl_lookup_symbol_x > > ^ bfd Ah, no, sorry, these are the runtime link editor/loader. So probably spending quite some time resolving symbols in large binaries. -- Thanks, ~Nick Desaulniers