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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 33F3EC43381 for ; Thu, 11 Mar 2021 00:09:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 14E5264F8B for ; Thu, 11 Mar 2021 00:09:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229729AbhCKAJO (ORCPT ); Wed, 10 Mar 2021 19:09:14 -0500 Received: from mail-io1-f54.google.com ([209.85.166.54]:44196 "EHLO mail-io1-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230183AbhCKAIz (ORCPT ); Wed, 10 Mar 2021 19:08:55 -0500 Received: by mail-io1-f54.google.com with SMTP id 81so19954677iou.11 for ; Wed, 10 Mar 2021 16:08:55 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=fb2yqbF1dxVEUN+xrNvG7hab3OpaMpUWqHj/zkqwZp4=; b=WIz8SKNtDnQl3t9OLwNBf9/2A6zdYmbxcA1h8UQGAORFCjbthXlC+Zzm1TVpaQyHp+ xZztQoQVbDhMjcL+VTuERvD2tsBsLI3NuaPX/b5+gjoo6uQ+YmQvTaRT0GhLrZMOOgMG GD0PVletd/EgBBkYhPQZWrzXq8ky6lsHDIMvGEm96Bz+8RQxJxQxHsYqVRPHmoTjDgDb ZIawGqFZOvhm8/CeLNDz5cqIuOLAV7gYM/Q7csf76T2TGU03NSXXWH/2qj6vJvRQhbWF yuRzZJ+1W4t4Y/82Ng4BkkV9kB6ndd+hl6eV80Ghunqu155a0TTXF49ODbXEKASCNgTe i/oQ== X-Gm-Message-State: AOAM530i25wTnlbEq6NLOfkxWUlq9fdOBWmRnb5bZBIfxENC5KBEhho9 Tud3vv3wHE1vb28MiXum7WnhIE5QKw== X-Google-Smtp-Source: ABdhPJzUUJBVsV9b4TAc7jdSClCSUd4HbAL/oFOWrhcl6aFgCIiaIAhzwolFFNIeHgQ07HZWuBQOFw== X-Received: by 2002:a02:272d:: with SMTP id g45mr1020900jaa.117.1615421333299; Wed, 10 Mar 2021 16:08:53 -0800 (PST) Received: from xps15.herring.priv ([64.188.179.253]) by smtp.googlemail.com with ESMTPSA id x17sm484351ilm.40.2021.03.10.16.08.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Mar 2021 16:08:52 -0800 (PST) From: Rob Herring To: Will Deacon , Catalin Marinas , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Jiri Olsa , Mark Rutland Cc: Ian Rogers , Alexander Shishkin , honnappa.nagarahalli@arm.com, Zachary.Leaf@arm.com, Raphael Gault , Jonathan Cameron , Namhyung Kim , Itaru Kitayama , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v6 04/10] libperf: Add evsel mmap support Date: Wed, 10 Mar 2021 17:08:31 -0700 Message-Id: <20210311000837.3630499-5-robh@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210311000837.3630499-1-robh@kernel.org> References: <20210311000837.3630499-1-robh@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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_base() which primarily for users/tests to check if userspace access is enabled. Signed-off-by: Rob Herring --- v6: - split mmap struct into it's own xyarray v5: - Create an mmap for every underlying event opened. Due to this, we need a different way to get the mmap ptr, so perf_evsel__mmap_base() is introduced. v4: - Change perf_evsel__mmap size to pages instead of bytes v3: - New patch split out from user access patch --- tools/lib/perf/Documentation/libperf.txt | 2 + tools/lib/perf/evsel.c | 51 ++++++++++++++++++++++++ tools/lib/perf/include/internal/evsel.h | 1 + tools/lib/perf/include/perf/evsel.h | 2 + tools/lib/perf/libperf.map | 2 + 5 files changed, 58 insertions(+) diff --git a/tools/lib/perf/Documentation/libperf.txt b/tools/lib/perf/Documentation/libperf.txt index 0c74c30ed23a..a2c73df191ca 100644 --- a/tools/lib/perf/Documentation/libperf.txt +++ b/tools/lib/perf/Documentation/libperf.txt @@ -136,6 +136,8 @@ 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); + int perf_evsel__mmap(struct perf_evsel *evsel, int pages); + void *perf_evsel__mmap_base(struct perf_evsel *evsel, int cpu, int thread); 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..1057e9b15528 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) { @@ -38,6 +40,7 @@ void perf_evsel__delete(struct perf_evsel *evsel) } #define FD(e, x, y) (*(int *) xyarray__entry(e->fd, x, y)) +#define MMAP(e, x, y) (e->mmap ? ((struct perf_mmap *) xyarray__entry(e->mmap, x, y)) : NULL) int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads) { @@ -55,6 +58,13 @@ int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads) return evsel->fd != NULL ? 0 : -ENOMEM; } +static int perf_evsel__alloc_mmap(struct perf_evsel *evsel, int ncpus, int nthreads) +{ + evsel->mmap = xyarray__new(ncpus, nthreads, sizeof(struct perf_mmap)); + + return evsel->mmap != NULL ? 0 : -ENOMEM; +} + static int sys_perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu, int group_fd, @@ -137,6 +147,8 @@ void perf_evsel__free_fd(struct perf_evsel *evsel) { xyarray__delete(evsel->fd); evsel->fd = NULL; + xyarray__delete(evsel->mmap); + evsel->mmap = NULL; } void perf_evsel__close(struct perf_evsel *evsel) @@ -156,6 +168,45 @@ void perf_evsel__close_cpu(struct perf_evsel *evsel, int cpu) perf_evsel__close_fd_cpu(evsel, cpu); } +int perf_evsel__mmap(struct perf_evsel *evsel, int pages) +{ + int ret, cpu, thread; + struct perf_mmap_param mp = { + .prot = PROT_READ | PROT_WRITE, + .mask = (pages * page_size) - 1, + }; + + if (evsel->mmap == NULL && + perf_evsel__alloc_mmap(evsel, xyarray__max_x(evsel->fd), xyarray__max_y(evsel->fd)) < 0) + return -ENOMEM; + + for (cpu = 0; cpu < xyarray__max_x(evsel->fd); cpu++) { + for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) { + int fd = FD(evsel, cpu, thread); + struct perf_mmap *map = MMAP(evsel, cpu, thread); + + if (fd < 0) + continue; + + perf_mmap__init(map, NULL, false, NULL); + + ret = perf_mmap__mmap(map, &mp, fd, cpu); + if (ret) + return -1; + } + } + + return 0; +} + +void *perf_evsel__mmap_base(struct perf_evsel *evsel, int cpu, int thread) +{ + if (FD(evsel, cpu, thread) < 0 || MMAP(evsel, cpu, thread) == NULL) + return NULL; + + return MMAP(evsel, cpu, thread)->base; +} + int perf_evsel__read_size(struct perf_evsel *evsel) { u64 read_format = evsel->attr.read_format; diff --git a/tools/lib/perf/include/internal/evsel.h b/tools/lib/perf/include/internal/evsel.h index 1ffd083b235e..1c067d088bc6 100644 --- a/tools/lib/perf/include/internal/evsel.h +++ b/tools/lib/perf/include/internal/evsel.h @@ -41,6 +41,7 @@ struct perf_evsel { struct perf_cpu_map *own_cpus; struct perf_thread_map *threads; struct xyarray *fd; + struct xyarray *mmap; struct xyarray *sample_id; u64 *id; u32 ids; diff --git a/tools/lib/perf/include/perf/evsel.h b/tools/lib/perf/include/perf/evsel.h index c82ec39a4ad0..9f5265f2f39f 100644 --- a/tools/lib/perf/include/perf/evsel.h +++ b/tools/lib/perf/include/perf/evsel.h @@ -27,6 +27,8 @@ LIBPERF_API int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map * struct perf_thread_map *threads); LIBPERF_API void perf_evsel__close(struct perf_evsel *evsel); LIBPERF_API void perf_evsel__close_cpu(struct perf_evsel *evsel, int cpu); +LIBPERF_API int perf_evsel__mmap(struct perf_evsel *evsel, int pages); +LIBPERF_API void *perf_evsel__mmap_base(struct perf_evsel *evsel, int cpu, int thread); LIBPERF_API int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread, struct perf_counts_values *count); LIBPERF_API int perf_evsel__enable(struct perf_evsel *evsel); diff --git a/tools/lib/perf/libperf.map b/tools/lib/perf/libperf.map index 7be1af8a546c..0b993de15830 100644 --- a/tools/lib/perf/libperf.map +++ b/tools/lib/perf/libperf.map @@ -23,6 +23,8 @@ LIBPERF_0.0.1 { perf_evsel__disable; perf_evsel__open; perf_evsel__close; + perf_evsel__mmap; + perf_evsel__mmap_base; perf_evsel__read; perf_evsel__cpus; perf_evsel__threads; -- 2.27.0