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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 912FBC43463 for ; Fri, 18 Sep 2020 14:33:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 195CF208C3 for ; Fri, 18 Sep 2020 14:33:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JMfksy8s" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726681AbgIROdp (ORCPT ); Fri, 18 Sep 2020 10:33:45 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:20280 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726126AbgIROdo (ORCPT ); Fri, 18 Sep 2020 10:33:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600439623; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Lc1gdBcSlwW1Myg1j82ImIPmW/PKiG30x2XN4oGwKHM=; b=JMfksy8sawvjzuQ4O1vedj4n4U2ae+7m0dEvb/h813QvhmcDrE+zEXZAoyZvBnfjQV4yR2 QFwq0NlU8SWLfB7/+j+xNJ0JFiY/be1Php0w0qrGsgQIqHmRUgXStXXk9u/SsfnMaK5ylV b2zoQTvs0nDE4ZeK6STDB0Mng2YeeBA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-364-313U2Tk8MHy_GT9nKyn5qg-1; Fri, 18 Sep 2020 10:33:38 -0400 X-MC-Unique: 313U2Tk8MHy_GT9nKyn5qg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EBEC4802B69; Fri, 18 Sep 2020 14:33:35 +0000 (UTC) Received: from krava (ovpn-114-24.ams2.redhat.com [10.36.114.24]) by smtp.corp.redhat.com (Postfix) with SMTP id 42B0C5D9E4; Fri, 18 Sep 2020 14:33:32 +0000 (UTC) Date: Fri, 18 Sep 2020 16:33:31 +0200 From: Jiri Olsa To: Rob Herring Cc: Will Deacon , Catalin Marinas , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Alexander Shishkin , Namhyung Kim , Raphael Gault , Mark Rutland , Jonathan Cameron , Ian Rogers , honnappa.nagarahalli@arm.com Subject: Re: [PATCH v3 05/10] libperf: Add libperf_evsel__mmap() Message-ID: <20200918143331.GF2626435@krava> References: <20200911215118.2887710-1-robh@kernel.org> <20200911215118.2887710-6-robh@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200911215118.2887710-6-robh@kernel.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 11, 2020 at 03:51:13PM -0600, Rob Herring wrote: > In order to support usersapce access, an event must be mmapped. While > there's already mmap support for evlist, the usecase is a bit different > than the self monitoring with userspace access. So let's add a new > perf_evsel__mmap() function to mmap an evsel. This allows implementing > userspace access as a fastpath for perf_evsel__read(). > > The mmapped address is returned by perf_evsel__mmap() primarily for > users/tests to check if userspace access is enabled. > > Signed-off-by: Rob Herring > --- > v3: > - New patch split out from user access patch > --- > tools/lib/perf/Documentation/libperf.txt | 1 + > tools/lib/perf/evsel.c | 31 ++++++++++++++++++++++++ > tools/lib/perf/include/internal/evsel.h | 2 ++ > tools/lib/perf/include/perf/evsel.h | 2 ++ > tools/lib/perf/libperf.map | 1 + > 5 files changed, 37 insertions(+) > > diff --git a/tools/lib/perf/Documentation/libperf.txt b/tools/lib/perf/Documentation/libperf.txt > index 0c74c30ed23a..0b4694ce42b9 100644 > --- a/tools/lib/perf/Documentation/libperf.txt > +++ b/tools/lib/perf/Documentation/libperf.txt > @@ -136,6 +136,7 @@ SYNOPSIS > struct perf_thread_map *threads); > void perf_evsel__close(struct perf_evsel *evsel); > void perf_evsel__close_cpu(struct perf_evsel *evsel, int cpu); > + void *perf_evsel__mmap(struct perf_evsel *evsel, size_t length); > int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread, > struct perf_counts_values *count); > int perf_evsel__enable(struct perf_evsel *evsel); > diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c > index 4dc06289f4c7..99fa53dc0887 100644 > --- a/tools/lib/perf/evsel.c > +++ b/tools/lib/perf/evsel.c > @@ -11,10 +11,12 @@ > #include > #include > #include > +#include > #include > #include > #include > #include > +#include > > void perf_evsel__init(struct perf_evsel *evsel, struct perf_event_attr *attr) > { > @@ -156,6 +158,35 @@ void perf_evsel__close_cpu(struct perf_evsel *evsel, int cpu) > perf_evsel__close_fd_cpu(evsel, cpu); > } > > +void *perf_evsel__mmap(struct perf_evsel *evsel, size_t length) > +{ could you rather use 'int pages' insted of length as we do in perf_evlist__mmap, so we keep the same interface len = (pages + 1) * page_size thanks, jirka