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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 A24ABC10F12 for ; Mon, 15 Apr 2019 12:04:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 707A0206BA for ; Mon, 15 Apr 2019 12:04:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="qJsspAKo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727369AbfDOMEt (ORCPT ); Mon, 15 Apr 2019 08:04:49 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:42132 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727329AbfDOMEs (ORCPT ); Mon, 15 Apr 2019 08:04:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=VmLFfbiaIcxEWV4kEBlZ0BMPymLpnk8TU9PQIRS9AOo=; b=qJsspAKowlGOwC6n3mabzISmE 0kGla+MQ7pKk4zj4oSPamzisYvhl/K44Gjq+xY5rYDq7QtsxmbcqqtCaLzcvlWNuTqFETdsPQbbor a0r1ldAqhK3VpnA5UqdIv083vxZwKs6wmIBcsTly73vTdJQrCuSR/WlSUpjru74i+VIdsaeFPWb5U I1LQirgdWf7/RdmNunzOpqVsNMCQtHnjDYnC0pg72Ez9/21otYzfUI9Cx2fy6TM2tJDb27bM7Gbyv TcH8UaNkedUyaiC5mTZwExDDqBtiU4xSJ4locOaZZZA2HNqbHkvGbY+/047wqw/MZQ7VTSKVA40/J AeWh7RmTA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hG0Lu-0004Im-35; Mon, 15 Apr 2019 12:04:46 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 5A56128B6D257; Mon, 15 Apr 2019 14:04:44 +0200 (CEST) Date: Mon, 15 Apr 2019 14:04:44 +0200 From: Peter Zijlstra To: Bandan Das Cc: Ingo Molnar , Arnaldo Carvalho de Melo , Jiri Olsa , linux-kernel@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH] perf/x86: descriptive failure messages for PMU init Message-ID: <20190415120444.GN11158@hirez.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 12, 2019 at 03:09:17PM -0400, Bandan Das wrote: > > There's a default warning message that gets printed, however, > there are various failure conditions: > - a msr read can fail > - a msr write can fail > - a msr has an unexpected value > - all msrs have unexpected values (disable PMU) > > Also, commit commit 005bd0077a79 ("perf/x86: Modify error message in > virtualized environment") completely removed printing the msr in > question but these messages could be helpful for debugging vPMUs as > well. Add them back and change them to pr_debugs, this keeps the > behavior the same for baremetal. > > Lastly, use %llx to silence checkpatch Yuck... if you're debugging a hypervisor, you can bloody well run your own kernel with additional print slattered around. The whole make an exception for virt bullshit was already pushing it, this is just insane. > @@ -266,12 +282,30 @@ static bool check_hw_exists(void) > return true; > > msr_fail: > - if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) { > + if (virt) > pr_cont("PMU not available due to virtualization, using software events only.\n"); > - } else { > - pr_cont("Broken PMU hardware detected, using software events only.\n"); > - pr_err("Failed to access perfctr msr (MSR %x is %Lx)\n", > - reg, val_new); > + switch (status) { > + case READ_FAIL: > + if (virt) > + pr_debug("Failed to read perfctr msr (MSR %x)\n", reg); > + else > + pr_err("Failed to read perfctr msr (MSR %x)\n", reg); > + break; > + case WRITE_FAIL: > + if (virt) > + pr_debug("Failed to write perfctr msr (MSR %x, wrote: %llx, read: %llx)\n", > + reg, val, val_new); > + else > + pr_err("Failed to write perfctr msr (MSR %x, wrote: %llx, read: %llx)\n", > + reg, val, val_new); > + break; > + case PMU_FAIL: > + /* fall through for default message */ > + default: > + if (virt) > + pr_debug("Broken PMU hardware detected, using software events only.\n"); > + else > + pr_cont("Broken PMU hardware detected, using software events only.\n"); > }