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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 6181BEB64DD for ; Wed, 9 Aug 2023 09:11:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=sbBbY9aUIwFS8ESZYanI07iiZvQaE3XV0Jo7bIyoNxE=; b=lSvbGx/IvxRCeJ EAoNkg4RNQgq1/N+z5m0QIBNKiaPGpDlAMoIzsDJAg+BBcnQ4ByG/SmATsAtAQDw3t+XUfBrPE2/F aPmK7CVBcZBN4WadvHGgINJz5u1yre0wVkVn+xL0yqkw8aGw9757h9x6ESxCpoa9ebKlTFJC04N8X Xm0CgXoKRh4BzJ4QgTY8RSr74Fcd5QchZP180VrmDrEV4o4d/h4YC0iHGFSyYpDEoorzx84dSW+lY MtOf01A2cBR6+OY6ecBtHwhuIlLr6+1C2FhkR4JxiXuL9uIzT1MS1X0TdMSf+Ilm5TT0y6pfMi8Gu +wIzvYkBcY0VanhgVloQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qTfDL-004R4F-0T; Wed, 09 Aug 2023 09:10:47 +0000 Received: from out-94.mta0.migadu.com ([2001:41d0:1004:224b::5e]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qTfDH-004R3D-2H for linux-arm-kernel@lists.infradead.org; Wed, 09 Aug 2023 09:10:45 +0000 Date: Wed, 9 Aug 2023 09:10:33 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1691572240; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=mvmzvKOGcM7VTd90ZNc4xMJrUWrhIk71OKZHdX1ecXM=; b=qrezTWI5AElJZqV9qQGcT9+Kg1Sv+qGaGp0ABG0ROC2hAq8H45AlVEdjXZmLHcWdvrAN3v UzgLZj9d3z52lNjfEviNP8FCivMcqGZikDTWDs5h5Ill5r0bZfDRxCFUdB+utjW4CZS/M9 zYb9t9t6JFETPi3apcQaXR40eklcy1Y= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Marc Zyngier Cc: Huang Shijie , james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, pbonzini@redhat.com, peterz@infradead.org, ingo@redhat.com, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org, irogers@google.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-perf-users@vger.kernel.org, patches@amperecomputing.com, zwang@amperecomputing.com Subject: Re: [PATCH] perf/core: fix the bug in the event multiplexing Message-ID: References: <20230809013953.7692-1-shijie@os.amperecomputing.com> <864jl8ha8y.wl-maz@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <864jl8ha8y.wl-maz@kernel.org> X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230809_021044_203423_C9CDB11B X-CRM114-Status: GOOD ( 10.68 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Aug 09, 2023 at 09:48:29AM +0100, Marc Zyngier wrote: [...] > Another question is how the same thing is handled on x86? Maybe they > don't suffer from this problem thanks to specific architectural > features, but it'd be good to find out, as this may guide the > implementation in a different way. I'm pretty sure the bug here is arm64 specific. x86 (at least on intel) fetches the guest PMU context from the perf driver w/ irqs disabled immediately before entering the guest (see atomic_switch_perf_msrs()). -- Thanks, Oliver _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel