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=-5.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 BFBC0C3A59C for ; Fri, 16 Aug 2019 13:05:32 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8FDC62064A for ; Fri, 16 Aug 2019 13:05:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="kCWd9cKp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8FDC62064A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=/9iTWUsckA02zZPz2fH5ge0vL8KmDYQMt3Q9xwoJfLo=; b=kCWd9cKpIdE3Ik L/HWCFrIDg8zR3Jof95+uE0GRvdtWH6PaBbvRvZU0v5wpa6HU7k1UngJYd2G395Qrjo0GK8zVBrN4 mOmk6/FBo/j9h5QOulPCpVvsum3QbJKp2X17Ir2AAJvEasgGPUKuoxdIDkLdBNdQHplTfahzUFC5n od35yKuITWUy07ehnPzQoLquuzR5z7OKmyRVgAzQDPqJlF8xhwYCBmAiaazw5ys5+JOh/W/3aPGh5 Cuv7m8cUHn3fhQeGX0daVwZXqB+uUDOjfYDAH9q3om1IJxrwY3TUB3ha/uRgEvzklySDbH184a1W3 2QWxYCVfkRKjpY30lSWw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hybv8-0003Mv-Fa; Fri, 16 Aug 2019 13:05:31 +0000 Received: from mga07.intel.com ([134.134.136.100]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hybr4-00075z-PR for linux-arm-kernel@lists.infradead.org; Fri, 16 Aug 2019 13:01:20 +0000 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Aug 2019 06:01:17 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,393,1559545200"; d="scan'208";a="171409585" Received: from ahunter-desktop.fi.intel.com (HELO [10.237.72.122]) ([10.237.72.122]) by orsmga008.jf.intel.com with ESMTP; 16 Aug 2019 06:01:12 -0700 Subject: Re: [PATCH v5] perf machine: arm/arm64: Improve completeness for kernel address space To: Leo Yan References: <20190815082521.16885-1-leo.yan@linaro.org> <20190815113242.GA28881@leoy-ThinkPad-X240s> <20190816014541.GA17960@leoy-ThinkPad-X240s> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: <363577f1-097e-eddd-a6ca-b23f644dd8ce@intel.com> Date: Fri, 16 Aug 2019 16:00:02 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190816014541.GA17960@leoy-ThinkPad-X240s> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190816_060118_988855_56E79231 X-CRM114-Status: GOOD ( 22.98 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Song Liu , Mathieu Poirier , Daniel Borkmann , Suzuki Poulouse , Alexander Shishkin , netdev@vger.kernel.org, coresight@lists.linaro.org, Alexei Starovoitov , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Peter Zijlstra , Yonghong Song , Namhyung Kim , bpf@vger.kernel.org, Jiri Olsa , Martin KaFai Lau , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 16/08/19 4:45 AM, Leo Yan wrote: > Hi Adrian, > > On Thu, Aug 15, 2019 at 02:45:57PM +0300, Adrian Hunter wrote: > > [...] > >>>> How come you cannot use kallsyms to get the information? >>> >>> Thanks for pointing out this. Sorry I skipped your comment "I don't >>> know how you intend to calculate ARM_PRE_START_SIZE" when you reviewed >>> the patch v3, I should use that chance to elaborate the detailed idea >>> and so can get more feedback/guidance before procceed. >>> >>> Actually, I have considered to use kallsyms when worked on the previous >>> patch set. >>> >>> As mentioned in patch set v4's cover letter, I tried to implement >>> machine__create_extra_kernel_maps() for arm/arm64, the purpose is to >>> parse kallsyms so can find more kernel maps and thus also can fixup >>> the kernel start address. But I found the 'perf script' tool directly >>> calls machine__get_kernel_start() instead of running into the flow for >>> machine__create_extra_kernel_maps(); >> >> Doesn't it just need to loop through each kernel map to find the lowest >> start address? > > Based on your suggestion, I worked out below change and verified it > can work well on arm64 for fixing up start address; please let me know > if the change works for you? How does that work if take a perf.data file to a machine with a different architecture? > > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c > index f6ee7fbad3e4..51d78313dca1 100644 > --- a/tools/perf/util/machine.c > +++ b/tools/perf/util/machine.c > @@ -2671,9 +2671,26 @@ int machine__nr_cpus_avail(struct machine *machine) > return machine ? perf_env__nr_cpus_avail(machine->env) : 0; > } > > +static int machine__fixup_kernel_start(void *arg, > + const char *name __maybe_unused, > + char type, > + u64 start) > +{ > + struct machine *machine = arg; > + > + type = toupper(type); > + > + /* Fixup for text, weak, data and bss sections. */ > + if (type == 'T' || type == 'W' || type == 'D' || type == 'B') > + machine->kernel_start = min(machine->kernel_start, start); > + > + return 0; > +} > + > int machine__get_kernel_start(struct machine *machine) > { > struct map *map = machine__kernel_map(machine); > + char filename[PATH_MAX]; > int err = 0; > > /* > @@ -2687,6 +2704,7 @@ int machine__get_kernel_start(struct machine *machine) > machine->kernel_start = 1ULL << 63; > if (map) { > err = map__load(map); > /* > * On x86_64, PTI entry trampolines are less than the > * start of kernel text, but still above 2^63. So leave > @@ -2695,6 +2713,16 @@ int machine__get_kernel_start(struct machine *machine) > if (!err && !machine__is(machine, "x86_64")) > machine->kernel_start = map->start; > } > + > + machine__get_kallsyms_filename(machine, filename, PATH_MAX); > + > + if (symbol__restricted_filename(filename, "/proc/kallsyms")) > + goto out; > + > + if (kallsyms__parse(filename, machine, machine__fixup_kernel_start)) > + pr_warning("Fail to fixup kernel start address. skipping...\n"); > + > +out: > return err; > } > > Thanks, > Leo Yan > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel