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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 88D80C43334 for ; Mon, 4 Jul 2022 15:07:43 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Lc8LQ1STyz3cf6 for ; Tue, 5 Jul 2022 01:07:42 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20210112 header.b=c7LZpgpH; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=flex--elver.bounces.google.com (client-ip=2a00:1450:4864:20::549; helo=mail-ed1-x549.google.com; envelope-from=32qhdygukdaykr1kxmuumrk.iusrot03vvi-jk1royzy.u5rghy.uxm@flex--elver.bounces.google.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20210112 header.b=c7LZpgpH; dkim-atps=neutral Received: from mail-ed1-x549.google.com (mail-ed1-x549.google.com [IPv6:2a00:1450:4864:20::549]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Lc8JX2t9Nz30Lp for ; Tue, 5 Jul 2022 01:06:04 +1000 (AEST) Received: by mail-ed1-x549.google.com with SMTP id v16-20020a056402349000b00435a1c942a9so7412410edc.15 for ; Mon, 04 Jul 2022 08:06:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=0mVGJO2my8t1HZTqH29Koygvc/XGcDZ6vWpb1jdDT4o=; b=c7LZpgpHCMEBj4kEkGYT6bIghj7rNP9OT0wV7natbn5wuqgLWU/zG9DSmlQ3UoI0nM MI4O6Yh+OcLIuk2ut/UkMTguYgLY7CRzA22Nl6fr3P2zFMYeTmGQmVqsEFwVmEbhQ6OK fzW4NNfl1lbwaGdyJPbQTgrp78RaKY7f6kZBMtyl+6RXzcPxksBXHu63hC9eFKG/bMPV RaIopRqFLF6DUEH5O1JW3to4T/kOCMvFYMeqTdSydrxqLwRnWOFUO0Df8H0K5KNdjHHJ tfKLT8izTPB0q+KzUVb+TsNCU3Ae+1Iq/NAZaHYQYOFNSHtTznzKAwdaMHkQ3wSbp6QS l/fQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=0mVGJO2my8t1HZTqH29Koygvc/XGcDZ6vWpb1jdDT4o=; b=BpPy5qgyHTfKApl0Kbic1fFRIym2A397MbooSLwInJcbJNwbC6xPFAA24+tUQVTHha iIu1VkU5Jfex4jngc8qSnXsuMX1bf/JzvfCtonoJFYxxJnxchq028n06qpvJLjuaViQr jBgmhdM3KB6ZeUiNfwkEti7YdIiNX798tUYda2RLW0dHgaiM/ilszomkyXyZOiJkTNpw seum0JRW50JMXN5PMZLi1ppjc38ZtHVXem5hdkV23Z3WnsO1xUt5gg0HWprCl8KaoQ0r hB1YhyUjaYHWQCDg2VaTY97lakeLIhfJgCwQWF2ayfWE529Wd3okxLjaw5ktaFTsilHN zApw== X-Gm-Message-State: AJIora8ppQJWLhuRa6Ht7pYi3ggo9UpVUHV95w5QYBVeIDL/ShVsZR5j e4tTuDCqRbblANtX67ry6v8SL3ed6g== X-Google-Smtp-Source: AGRyM1u1tV984VAUKT5L9i/jwt0YX43hTGCtQ8Dkdr+VsujPNvT+0VKdHYhVoQYNC2BBRUvkHBjcbLjtmw== X-Received: from elver.muc.corp.google.com ([2a00:79e0:9c:201:6edf:e1bc:9a92:4ad0]) (user=elver job=sendgmr) by 2002:aa7:cd17:0:b0:435:bd7e:2efb with SMTP id b23-20020aa7cd17000000b00435bd7e2efbmr40768145edw.180.1656947161289; Mon, 04 Jul 2022 08:06:01 -0700 (PDT) Date: Mon, 4 Jul 2022 17:05:02 +0200 In-Reply-To: <20220704150514.48816-1-elver@google.com> Message-Id: <20220704150514.48816-3-elver@google.com> Mime-Version: 1.0 References: <20220704150514.48816-1-elver@google.com> X-Mailer: git-send-email 2.37.0.rc0.161.g10f37bed90-goog Subject: [PATCH v3 02/14] perf/hw_breakpoint: Provide hw_breakpoint_is_used() and use in test From: Marco Elver To: elver@google.com, Peter Zijlstra , Frederic Weisbecker , Ingo Molnar Content-Type: text/plain; charset="UTF-8" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , linux-sh@vger.kernel.org, Alexander Shishkin , x86@kernel.org, linuxppc-dev@lists.ozlabs.org, Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, kasan-dev@googlegroups.com, Namhyung Kim , Thomas Gleixner , Jiri Olsa , Dmitry Vyukov Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Provide hw_breakpoint_is_used() to check if breakpoints are in use on the system. Use it in the KUnit test to verify the global state before and after a test case. Signed-off-by: Marco Elver --- v3: * New patch. --- include/linux/hw_breakpoint.h | 3 +++ kernel/events/hw_breakpoint.c | 29 +++++++++++++++++++++++++++++ kernel/events/hw_breakpoint_test.c | 12 +++++++++++- 3 files changed, 43 insertions(+), 1 deletion(-) diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h index 78dd7035d1e5..a3fb846705eb 100644 --- a/include/linux/hw_breakpoint.h +++ b/include/linux/hw_breakpoint.h @@ -74,6 +74,7 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr, extern int register_perf_hw_breakpoint(struct perf_event *bp); extern void unregister_hw_breakpoint(struct perf_event *bp); extern void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events); +extern bool hw_breakpoint_is_used(void); extern int dbg_reserve_bp_slot(struct perf_event *bp); extern int dbg_release_bp_slot(struct perf_event *bp); @@ -121,6 +122,8 @@ register_perf_hw_breakpoint(struct perf_event *bp) { return -ENOSYS; } static inline void unregister_hw_breakpoint(struct perf_event *bp) { } static inline void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events) { } +static inline bool hw_breakpoint_is_used(void) { return false; } + static inline int reserve_bp_slot(struct perf_event *bp) {return -ENOSYS; } static inline void release_bp_slot(struct perf_event *bp) { } diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index f32320ac02fd..fd5cd1f9e7fc 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -604,6 +604,35 @@ void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events) } EXPORT_SYMBOL_GPL(unregister_wide_hw_breakpoint); +/** + * hw_breakpoint_is_used - check if breakpoints are currently used + * + * Returns: true if breakpoints are used, false otherwise. + */ +bool hw_breakpoint_is_used(void) +{ + int cpu; + + if (!constraints_initialized) + return false; + + for_each_possible_cpu(cpu) { + for (int type = 0; type < TYPE_MAX; ++type) { + struct bp_cpuinfo *info = get_bp_info(cpu, type); + + if (info->cpu_pinned) + return true; + + for (int slot = 0; slot < nr_slots[type]; ++slot) { + if (info->tsk_pinned[slot]) + return true; + } + } + } + + return false; +} + static struct notifier_block hw_breakpoint_exceptions_nb = { .notifier_call = hw_breakpoint_exceptions_notify, /* we need to be notified first */ diff --git a/kernel/events/hw_breakpoint_test.c b/kernel/events/hw_breakpoint_test.c index 433c5c45e2a5..5ced822df788 100644 --- a/kernel/events/hw_breakpoint_test.c +++ b/kernel/events/hw_breakpoint_test.c @@ -294,7 +294,14 @@ static struct kunit_case hw_breakpoint_test_cases[] = { static int test_init(struct kunit *test) { /* Most test cases want 2 distinct CPUs. */ - return num_online_cpus() < 2 ? -EINVAL : 0; + if (num_online_cpus() < 2) + return -EINVAL; + + /* Want the system to not use breakpoints elsewhere. */ + if (hw_breakpoint_is_used()) + return -EBUSY; + + return 0; } static void test_exit(struct kunit *test) @@ -308,6 +315,9 @@ static void test_exit(struct kunit *test) kthread_stop(__other_task); __other_task = NULL; } + + /* Verify that internal state agrees that no breakpoints are in use. */ + KUNIT_EXPECT_FALSE(test, hw_breakpoint_is_used()); } static struct kunit_suite hw_breakpoint_test_suite = { -- 2.37.0.rc0.161.g10f37bed90-goog