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 F1054C433F5 for ; Wed, 16 Feb 2022 13:13:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233715AbiBPNN2 (ORCPT ); Wed, 16 Feb 2022 08:13:28 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:47526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233688AbiBPNN2 (ORCPT ); Wed, 16 Feb 2022 08:13:28 -0500 Received: from mail-ed1-x52a.google.com (mail-ed1-x52a.google.com [IPv6:2a00:1450:4864:20::52a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7ED126A2D3 for ; Wed, 16 Feb 2022 05:13:14 -0800 (PST) Received: by mail-ed1-x52a.google.com with SMTP id f17so3876725edd.2 for ; Wed, 16 Feb 2022 05:13:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=C2p4IUdETvsJDn4La4k2PCI07l5Bxa5zsybCeAbirFE=; b=cgTmNT+lR7bIEtc+0RAP+11VPLYqnh/5AYxJB7yMRpBjQ4E7jT1GDIbYfOvueK0OGj ezlXhWvCIyOfOIoK9wPgSJW5Qvz/Tq6u5h2BHhHxA3/M9FjYgCtvpraidt0TcJvapxBP PSGEHjx8CPFzhxjV/xFtu0YKK3FRIyafADQKj33KP8ehSq3QyLbQ80nv3lfGkGZy9f/e 8kQ7cTK1XsTlQXalf/x5+5L17ozGIHBzyLvlGsemDJy2T8DzllilABCyKj6Q53kFjDb3 RQSuQSmRXKPAT2IGMBr2NO6prlzGpfdzqmcWk3/hpqV03GHQ07FnrM1zwgr+L9AvVUxb x2+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=C2p4IUdETvsJDn4La4k2PCI07l5Bxa5zsybCeAbirFE=; b=HrMvu/JGmZbHOwQ0Sz0wmmzBMjfgJwAp1y7+JRnC4yjLSn1/Rbz6aMKUquKffMooPO iqwA9UEl+OS0W8pLx7bYqBR3Np/be4XNh3xJElEtfdg+mmlBOJFd/dfbLdrPku0t/3hc GNr7/ZWwmeJx1JyKRvqWnQa2lmv2elp40fcunpfZkULoUaEEMqKpYWW1j22ImpvdBpBl cbcVdpAqhnDd0ucouyMSPUJq+GESBjlhb1IQtwfU3xf2DC/hQnnOJFRikHDc+j7aKc62 NPEH8CidRvprv9SqeeOTvRji01/82UBzXEx1FNhQy5RFYTEdIf6WUypkiiG2fe04la+1 Jehg== X-Gm-Message-State: AOAM5338KXVOAvw/WiqGM8V020W2ErRNLghvSyUP4kozOCWKqx/Q6rxo iY8f2UkfXMXiYVHq7SET4bNnsQ== X-Google-Smtp-Source: ABdhPJytGpaXpnUA2XqnoVWtsq4DkTHuirdUMy5k13A5Kf2GGU7VKMXxrZ1WP9LXlvA/21mEfeqgSA== X-Received: by 2002:a05:6402:742:b0:410:a427:3634 with SMTP id p2-20020a056402074200b00410a4273634mr2941621edy.304.1645017193316; Wed, 16 Feb 2022 05:13:13 -0800 (PST) Received: from leoy-ThinkPad-X240s ([104.245.96.223]) by smtp.gmail.com with ESMTPSA id h5sm4817787ejo.124.2022.02.16.05.13.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Feb 2022 05:13:12 -0800 (PST) Date: Wed, 16 Feb 2022 21:13:06 +0800 From: Leo Yan To: Dmitry Vyukov Cc: John Garry , Will Deacon , Marco Elver , Thomas Richter , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, acme@kernel.org, svens@linux.ibm.com, gor@linux.ibm.com, sumanthk@linux.ibm.com, hca@linux.ibm.com, Mark Rutland , "linux-arm-kernel@lists.infradead.org" Subject: Re: Test 73 Sig_trap fails on arm64 (was Re: [PATCH] perf test: Test 73 Sig_trap fails on s390) Message-ID: <20220216131306.GA56419@leoy-ThinkPad-X240s> References: <90efb5a9-612a-919e-cf2f-c528692d61e2@huawei.com> <20220118091827.GA98966@leoy-ThinkPad-X240s> <20220118124343.GC98966@leoy-ThinkPad-X240s> <06412caf-42e4-5c4b-c9b3-9691075405bd@huawei.com> <20220215143459.GB7592@willie-the-truck> <8c582e45-0954-a2ea-764a-4dd78a464988@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org On Wed, Feb 16, 2022 at 12:54:16PM +0100, Dmitry Vyukov wrote: > On Wed, 16 Feb 2022 at 12:47, John Garry wrote: [...] > > > Signals make this messy, as the step logic will step_into_ the signal > > > handler -- we have to do this, otherwise we would miss break/watchpoints > > > triggered by the signal handler if we had disabled them for the step. > > > However, it means that when we return back from the signal handler we will > > > run back into the break/watchpoint which we initially stepped over. When > > > perf uses SIGTRAP to notify userspace that we hit a break/watchpoint, > > > then we'll get stuck because we'll step into the handler every time. > > > > > > Hopefully that clears things up a bit. Ideally, the kernel wouldn't > > > pretend to handle this stepping at all for arm64 as it adds a bunch of > > > complexity, overhead to our context-switch and I don't think the current > > > behaviour is particularly useful. > > > > > > > Right, so what I am hearing altogether is that for now we should just > > skip this test. > > > > And since the kernel does not seem to advertise this capability we need > > to disable for specific architectures. > > It does and fwiw I am just trying to use it. Things work only on x86 so far. So here we have agreement to disable the cases for Arm64/Arm. John, since you put much efforts to follow up the issue, I'd like to leave decision to you if you want to proceed for patches? Otherwise, I will send patches to disable cases in perf. Thanks, Leo