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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B53C6C433FE for ; Fri, 21 Oct 2022 07:38:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229695AbiJUHiH (ORCPT ); Fri, 21 Oct 2022 03:38:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229585AbiJUHiE (ORCPT ); Fri, 21 Oct 2022 03:38:04 -0400 Received: from mail-yb1-xb2e.google.com (mail-yb1-xb2e.google.com [IPv6:2607:f8b0:4864:20::b2e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 57C7B239201 for ; Fri, 21 Oct 2022 00:38:03 -0700 (PDT) Received: by mail-yb1-xb2e.google.com with SMTP id 126so2409441ybw.3 for ; Fri, 21 Oct 2022 00:38:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=YqCI81aYTBUvq0AjF/BYw/CwZWDfTatRIRM86fy8mzM=; b=hdGApCLDmq0zk1404naN816WsPf7cus4RecqB5gWNPeMIwXuVT2JpTqOAePyNFo0Q+ +A7vMQhDqeCFfi6RbOgeeW1dRh4oUJvWP0hZnDs/KK+Nv7HoCDL7+y5jUnB24RrIxW1V l9Grn4St0VsHs99MbtHIi8V8+4PhGRywmpkMY5QpBoXmPWTZOrPflcxxw9Cddy0OkLXA 1H83ZHNUriu0YQIACgBzfbWOrYIhJ4nYjCzGVKWq6lY+RHeOyNcAEqr07B+mZpQ06BZz JUWPvoaYDWVI28Wb9OBW92L2zM729XBkw1zK4NjdriUn0h0Tp9lUzd5pmxDXhdbubX15 x9Ag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=YqCI81aYTBUvq0AjF/BYw/CwZWDfTatRIRM86fy8mzM=; b=6doY0QrqgFbnHzL2idmbtQ56PbnpzeKD4Hqn130X9kATGPHU22JtqDj/SMpEUdy3/l vqq84NavULLjA9thYUS6N2EOJoLZr+YD6jG6E6nUA58fVkjakqla3EJf9Sc1LSN8Yy8j TmH8VwdE7Ta7GW9M+edEzww5vdljSoccRnF4kTxZsgv6lkWMtLwYNzkLTx2jA4QWxoEl 5TGDMf9ftRVTmTYOlZJd7D98ye7SoV1drBn7FU0p79hk39vxW1wQw7agPuPb4no4JyWb YoquvJWk7xT9U4Cpn/uI3NoeTj71KBOBzX++XX7yz2p4P9BQPX6Xi/872dXEUFq667ZS 5YFw== X-Gm-Message-State: ACrzQf2IkORJff3EPrqS6TZsIsdDgbQgIbNGu16H44P05OfX0U1IPm1v MKJbZjXYtH0KzbkujUy7BioqFgNUFk5kv96jaeZsBg== X-Google-Smtp-Source: AMsMyM62GSx0NWUinN6ObtQibLc5Ih1zlGVGyMCuv7Iu8ly2udUc3uKngmrdcVX2ldvl3SdCr2LW4qra3FYqJuzBJNY= X-Received: by 2002:a25:7b42:0:b0:6ca:1d03:2254 with SMTP id w63-20020a257b42000000b006ca1d032254mr8096145ybc.584.1666337882424; Fri, 21 Oct 2022 00:38:02 -0700 (PDT) MIME-Version: 1.0 References: <20220915150417.722975-19-glider@google.com> <20221019173620.10167-1-youling257@gmail.com> In-Reply-To: From: Marco Elver Date: Fri, 21 Oct 2022 00:37:26 -0700 Message-ID: Subject: Re: [PATCH v7 18/43] instrumented.h: add KMSAN support To: youling 257 Cc: Alexander Potapenko , Alexander Viro , Alexei Starovoitov , Andrew Morton , Andrey Konovalov , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Christoph Hellwig , Christoph Lameter , David Rientjes , Dmitry Vyukov , Eric Biggers , Eric Dumazet , Greg Kroah-Hartman , Herbert Xu , Ilya Leoshkevich , Ingo Molnar , Jens Axboe , Joonsoo Kim , Kees Cook , Mark Rutland , Matthew Wilcox , "Michael S. Tsirkin" , Pekka Enberg , Peter Zijlstra , Petr Mladek , Stephen Rothwell , Steven Rostedt , Thomas Gleixner , Vasily Gorbik , Vegard Nossum , Vlastimil Babka , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 20 Oct 2022 at 23:39, youling 257 wrote: > > PerfTop: 8253 irqs/sec kernel:75.3% exact: 100.0% lost: 0/0 drop: > 0/17899 [4000Hz cycles], (all, 8 CPUs) > --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- > > 14.87% [kernel] [k] 0xffffffff941d1f37 > 6.71% [kernel] [k] 0xffffffff942016cf > > what is 0xffffffff941d1f37? You need to build with debug symbols: CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y Then it'll show function names. > 2022-10-21 14:16 GMT+08:00, Marco Elver : > > On Thu, 20 Oct 2022 at 22:55, youling 257 wrote: > >> > >> How to use perf tool? > > > > The simplest would be to try just "perf top" - and see which kernel > > functions consume most CPU cycles. I would suggest you compare both > > kernels, and see if you can spot a function which uses more cycles% in > > the problematic kernel. > >