Received: by 2002:a05:6a10:22f:0:0:0:0 with SMTP id 15csp3169164pxk; Mon, 21 Sep 2020 07:01:50 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwwlJn4rVeVY4P8eve2dTJuWRO+tm65YYR54Cv8c+n5YA0hAf5YHVAIY7L242vcruDImSnw X-Received: by 2002:a17:906:49c6:: with SMTP id w6mr48760516ejv.445.1600696910598; Mon, 21 Sep 2020 07:01:50 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1600696910; cv=none; d=google.com; s=arc-20160816; b=DOREUUIDd6xacwNhbXZY6MUZuQac+9A7qyb+ohMP2nfuDi0TZCbdx2r615RQcU97Jf GcuHw044zGbpx3CLbi+5krDA6F1WfQnT2ZgxJnQZOPmuGf6ON0Y5uxmIasVM+kIVvIkH 34CnwzCy0+Nvn2GVH2AKq3yxf/IBM7CEcsI3ReRhZ+WngMu/wuLcaijXI/8czEvGqqZN M/pZbzQe9/oyuCpLAVdCKhYYL03w60PNoTvH+2l1tAtP4dAopkT8Snlz0Ud17HunChGy tiSg6xi0x4audalxdjiamce4/OrKfldbZBhOrXEkd6vdN0wfo5b3BwdLRt9uEs288B2J 0RgQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:user-agent:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :dkim-signature; bh=a4DF4W7dtH8e/HdbJnpntS4I8yTDTPerCU7Lh31WhNQ=; b=MA0oJ/u0QrrsTFLzNX/cbeixAI7oeCxu8tgcovUSEk1Mu1f/vx+5FHNCnIWSb9nf0q f5IRXWzxbjDLE8UYvoOYEcCYMIx1dToEVHpYioFH0GJ25a5uEdJtDDhoHGB48eomiqHZ 6KNf5tZHQRY8lorzwT1qlxscCpZybhRLQl6s6arQOcdh1kgX+KkqrbnmLFAoYBkJAgqu nemfQgA712RtG1beyAgkaXQProXxsC3ZCzO5vMAe8b932HuwCDrioArW1xo+NFZb4BgL xMLszwxXoURFB2Q/N6ad0R7rsmQRT5v+Xhr3Ztx0hcdUhOiN2hh6Ze1aM3zwYz65uFfe Aqlg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=wg9S+ccq; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id ng3si7877089ejb.720.2020.09.21.07.01.23; Mon, 21 Sep 2020 07:01:50 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=wg9S+ccq; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727107AbgIUN76 (ORCPT + 99 others); Mon, 21 Sep 2020 09:59:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:34346 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726496AbgIUN75 (ORCPT ); Mon, 21 Sep 2020 09:59:57 -0400 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 52F1E20866; Mon, 21 Sep 2020 13:59:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600696796; bh=a4DF4W7dtH8e/HdbJnpntS4I8yTDTPerCU7Lh31WhNQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=wg9S+ccqsDems1XcMj6eWPCpdmJ2G7w+rjxlyHduxbE5H7pjT+kzuyEjIROlO22rH JDTh02rcsjIObg8hrRocIUlihWizF1Ghdv/loTWSlrG9BWmGad/xgg14LZ+oJjN6wZ MgIcADkUToN3Vu5HCUYF0wrTHg+++B8cNEo52KJw= Date: Mon, 21 Sep 2020 14:59:52 +0100 From: Will Deacon To: Alexandru Elisei Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, maz@kernel.org, catalin.marinas@arm.com, swboyd@chromium.org, sumit.garg@linaro.org Subject: Re: [PATCH v6 0/7] arm_pmu: Use NMI for perf interrupt Message-ID: <20200921135951.GN2139@willie-the-truck> References: <20200819133419.526889-1-alexandru.elisei@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200819133419.526889-1-alexandru.elisei@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 19, 2020 at 02:34:12PM +0100, Alexandru Elisei wrote: > The series makes the arm_pmu driver use NMIs for the perf interrupt when > NMIs are available on the platform (currently, only arm64 + GICv3). To make > it easier to play with the patches, I've pushed a branch at [1]: This mostly looks good to me, but see some of the comments I left on the code. One other thing I'm not sure about is whether or not we should tell userspace that we're using an NMI for the sampling. Do any other architectures have a conditional NMI? Will