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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51445C4332F for ; Sat, 19 Nov 2022 01:52:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233248AbiKSBwz (ORCPT ); Fri, 18 Nov 2022 20:52:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233526AbiKSBwk (ORCPT ); Fri, 18 Nov 2022 20:52:40 -0500 Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BB538EB60 for ; Fri, 18 Nov 2022 17:34:54 -0800 (PST) Received: by mail-pl1-x64a.google.com with SMTP id c1-20020a170902d48100b0018723580343so5000751plg.15 for ; Fri, 18 Nov 2022 17:34:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:reply-to:from:to:cc :subject:date:message-id:reply-to; bh=CjK5nD/uvnQk7qUQi9oIboYcWNk4lZcV0pG+jDjHbYw=; b=sO/BixX+Fxa6IYPQU8TkdF+XFQ44C4ZySQ2iwNGf4nj3I51S8QIRUibkPiKNqU6bw1 j4PlnepiO1Ad8v/zZSnMeIBI68hxaFqyJGMZebX4cy3Jv14uXBvY/oT0aik++6OQL6oN DbLgAWDsPzUK72v+4dKMHKRTS+Pj0wR02zmTyQNbwMmm5J9cue1G73b6Acb3Oy+6Rqq7 SFCX3tIjVDK5Bkgwj3xiOgKx932eMjN+X5AA0/Lbv6Dl4c1cRTcxk/wdcfGn/cUpN1uD EJ0BOyIS/RA9GP99cIy1ORxMCIBlL+dVVmi0pQd37KDIkkhww3/YCplg0uN9lfWxW1qn tETw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:reply-to :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=CjK5nD/uvnQk7qUQi9oIboYcWNk4lZcV0pG+jDjHbYw=; b=m9ultfOJo2iOIC0zuZfFFjnqOfI4mhn9oTLUW8aM9wRzI/m3/+fPx+ErKXSlRqvoaO gboJ82e2Wp97vOKic4LM1NNVgWsIEBDVu5wfPizkDioPNia13pjEq8Co12/6450uSAM7 ipl/ajXtEpGj+1/aZuj5rZnj5iHdcwucDlk3YNAQSJ/9Sf3rDqtYWUCuoMv9gTfvQypw 4nv//jmsSrf2A0l57swcOXMcDxDQDsTZVfuTe9fujktKNy5xqq3WdZ+VK70a153xWCaU 61BoG3FA3iFvmibKRGB05ZWDQtBl9QxhytnrtVNkZec8aRuTRbx+jXfgRZFsEkfjGtL1 UoFA== X-Gm-Message-State: ANoB5pl9VlHn7qLRNniNMCOWHoNv0Bvyl0rw5Cqz7iU8mmT8NDFXgp4Q fcTJGRt0bYPmlNtfP1Vr8el6wOrE5Uc= X-Google-Smtp-Source: AA0mqf40VxY3bniB1w/5m0fnfOQyqSksKugX3b7aeyvG44COkqlBU1UDui2GOB4g4JxSgT+nQap4mhTD/UM= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a62:31c4:0:b0:56e:989d:7410 with SMTP id x187-20020a6231c4000000b0056e989d7410mr10648162pfx.1.1668821693609; Fri, 18 Nov 2022 17:34:53 -0800 (PST) Reply-To: Sean Christopherson Date: Sat, 19 Nov 2022 01:34:41 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.38.1.584.g0f3c55d4c2-goog Message-ID: <20221119013450.2643007-1-seanjc@google.com> Subject: [PATCH 0/9] tools: Make {clear,set}_bit() atomic for reals From: Sean Christopherson To: Yury Norov , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Marc Zyngier , Paolo Bonzini Cc: Andy Shevchenko , Rasmus Villemoes , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , James Morse , Alexandru Elisei , Suzuki K Poulose , Oliver Upton , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Sean Christopherson Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org For obvious reasons I'd like to route the this through Paolo's tree. In theory, taking just patch 5 through tip would work, but creating a topic branch seems like the way to go, though maybe I'm being overly paranoid. The current tip/perf/core doesn't have any conflicts, nor does it have new set_bit() or clear_bit() users. Code sitting in kvm/queue for 6.2 adds functionality that relies on clear_bit() being an atomic operation. Unfortunately, despite being implemented in atomic.h (among other strong hits that they should be atomic), clear_bit() and set_bit() aren't actually atomic (and of course I realized this _just_ after everything got queued up). Move current tools/ users of clear_bit() and set_bit() to the double-underscore versions (which tools/ already provides and documents as being non-atomic), and then implement clear_bit() and set_bit() as actual atomics to fix the KVM selftests bug. Perf and KVM are the only affected users. NVDIMM also has test code in tools/, but that builds against the kernel proper. The KVM code is well tested and fully audited. The perf code is lightly tested; if I understand the build system, it's probably not even fully compile tested. Patches 1 and 2 are completely unrelated and are fixes for patches sitting in kvm/queue. Paolo, they can be squashed if you want to rewrite history. Patch 3 fixes a hilarious collision in a KVM ARM selftest that will arise when clear_bit() is converted to an atomic. Patch 4 changes clear_bit() and set_bit() to take an "unsigned long" instead of an "int" so that patches 5-6 aren't accompanied by functional changes. I.e. if something in perf is somehow relying on "bit" being a signed int, failures will bisect to patch 4 and not to the supposed-to-be-a-nop conversion to __clear_bit() and __set_bit(). Patch 5-9 switch perf+KVM and complete the conversion. Applies on: git://git.kernel.org/pub/scm/virt/kvm/kvm.git queue Sean Christopherson (9): KVM: selftests: Add rdmsr_from_l2() implementation in Hyper-V eVMCS test KVM: selftests: Remove unused "vcpu" param to fix build error KVM: arm64: selftests: Enable single-step without a "full" ucall() tools: Take @bit as an "unsigned long" in {clear,set}_bit() helpers perf tools: Use dedicated non-atomic clear/set bit helpers KVM: selftests: Use non-atomic clear/set bit helpers in KVM tests tools: Drop conflicting non-atomic test_and_{clear,set}_bit() helpers tools: Drop "atomic_" prefix from atomic test_and_set_bit() tools: KVM: selftests: Convert clear/set_bit() to actual atomics tools/arch/x86/include/asm/atomic.h | 6 +++- tools/include/asm-generic/atomic-gcc.h | 13 ++++++- tools/include/asm-generic/bitops/atomic.h | 15 ++++---- tools/include/linux/bitmap.h | 34 ------------------- tools/perf/bench/find-bit-bench.c | 2 +- tools/perf/builtin-c2c.c | 6 ++-- tools/perf/builtin-kwork.c | 6 ++-- tools/perf/builtin-record.c | 6 ++-- tools/perf/builtin-sched.c | 2 +- tools/perf/tests/bitmap.c | 2 +- tools/perf/tests/mem2node.c | 2 +- tools/perf/util/affinity.c | 4 +-- tools/perf/util/header.c | 8 ++--- tools/perf/util/mmap.c | 6 ++-- tools/perf/util/pmu.c | 2 +- .../util/scripting-engines/trace-event-perl.c | 2 +- .../scripting-engines/trace-event-python.c | 2 +- tools/perf/util/session.c | 2 +- tools/perf/util/svghelper.c | 2 +- .../selftests/kvm/aarch64/arch_timer.c | 2 +- .../selftests/kvm/aarch64/debug-exceptions.c | 21 ++++++------ tools/testing/selftests/kvm/dirty_log_test.c | 34 +++++++++---------- .../selftests/kvm/include/ucall_common.h | 8 +++++ .../testing/selftests/kvm/lib/ucall_common.c | 2 +- .../selftests/kvm/x86_64/hyperv_evmcs.c | 13 +++++-- .../selftests/kvm/x86_64/hyperv_svm_test.c | 4 +-- .../selftests/kvm/x86_64/hyperv_tlb_flush.c | 2 +- 27 files changed, 102 insertions(+), 106 deletions(-) base-commit: 3321eef4acb51c303f0598d8a8493ca58528a054 -- 2.38.1.584.g0f3c55d4c2-goog