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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B5A6AC433EF for ; Wed, 27 Oct 2021 20:16:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A10A46103C for ; Wed, 27 Oct 2021 20:16:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240823AbhJ0UTR (ORCPT ); Wed, 27 Oct 2021 16:19:17 -0400 Received: from mail-oi1-f173.google.com ([209.85.167.173]:37754 "EHLO mail-oi1-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240671AbhJ0UTL (ORCPT ); Wed, 27 Oct 2021 16:19:11 -0400 Received: by mail-oi1-f173.google.com with SMTP id o83so5112182oif.4; Wed, 27 Oct 2021 13:16:46 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=XglJs1OrxOGXDZwQ6Z0xWT/fdEEcMb5WDcdtHAA51Ao=; b=3LUUhDrpVAIdEffQvEHKdYzu00qR+OQL2KM2+EqF3BPKf+jN+6KthuHdWNXih/0st6 1aYBv39CiO2OE94D6ZUghnnjlqdb1Mf+xkuAsNC/C3eRGgbei+6dY+M4+wZR/Cil+ogf pbuD5tn3GgjKNQtAb+AfrJAq4MUmHuORb7DxBotHbq4PbNlld9bu2zhz+mhfGzxyNiHO y/yWaNsnV0dQOzJgMhHZQaEjODg1KsqUm1ajSqsq7flV7mH23N/EeJNcBG+bpurMblfv /FZcIoIQEde1xFsSfRi0e+NW2/JkQdKz5+tWVgl9iawe9/jpQ/uz2ZSb/1zcZjS31ZT3 yMqQ== X-Gm-Message-State: AOAM53152eX+7P16EyTHyMI5trtb53NSVHdk9P7k1lskP0+7yJMrSkye 6qwzNN2GF62DhG+JKlYsKQ== X-Google-Smtp-Source: ABdhPJxX3AiZ/vuirHgymgSIPu02dS9OiXOc1XMBNH12+W2iAg30s4MUs+CWgL849GrCzTZnN0NyYw== X-Received: by 2002:a05:6808:238a:: with SMTP id bp10mr5367505oib.30.1635365805635; Wed, 27 Oct 2021 13:16:45 -0700 (PDT) Received: from xps15.herring.priv (66-90-148-213.dyn.grandenetworks.net. [66.90.148.213]) by smtp.googlemail.com with ESMTPSA id f10sm415332otc.26.2021.10.27.13.16.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 27 Oct 2021 13:16:45 -0700 (PDT) From: Rob Herring To: Will Deacon , Mark Rutland , Peter Zijlstra Cc: Jonathan Corbet , Catalin Marinas , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org Subject: [PATCH v12 2/5] perf: Add a counter for number of user access events in context Date: Wed, 27 Oct 2021 15:16:38 -0500 Message-Id: <20211027201641.2076427-3-robh@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211027201641.2076427-1-robh@kernel.org> References: <20211027201641.2076427-1-robh@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For controlling user space counter access, we need to know if any event in a context (currently scheduled or not) is using user space counters. Walking the context's list of events would be slow, so add a counter to track this. Reviewed-by: Mark Rutland Signed-off-by: Rob Herring --- v10: - Re-added. - Maintain the count in the perf core v9: - Dropped v8: - new patch --- include/linux/perf_event.h | 1 + kernel/events/core.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 34ebcc9af608..d733cac749e2 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -828,6 +828,7 @@ struct perf_event_context { int nr_events; int nr_active; + int nr_user; int is_active; int nr_stat; int nr_freq; diff --git a/kernel/events/core.c b/kernel/events/core.c index 744e8726c5b2..01290d150da3 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -1808,6 +1808,8 @@ list_add_event(struct perf_event *event, struct perf_event_context *ctx) list_add_rcu(&event->event_entry, &ctx->event_list); ctx->nr_events++; + if (event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT) + ctx->nr_user++; if (event->attr.inherit_stat) ctx->nr_stat++; @@ -1999,6 +2001,8 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx) event->attach_state &= ~PERF_ATTACH_CONTEXT; ctx->nr_events--; + if (event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT) + ctx->nr_user--; if (event->attr.inherit_stat) ctx->nr_stat--; -- 2.32.0