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 B7151C433EF for ; Fri, 1 Jul 2022 13:30:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231411AbiGANaN (ORCPT ); Fri, 1 Jul 2022 09:30:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229685AbiGANaL (ORCPT ); Fri, 1 Jul 2022 09:30:11 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3E89A12AEA; Fri, 1 Jul 2022 06:30:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1656682211; x=1688218211; h=message-id:subject:from:to:date:in-reply-to:references: mime-version:content-transfer-encoding; bh=+d47PHEG6GUuN8KKZaAK99mo1O1Vtw5dAs10yx1siLA=; b=kLB17VtznB/RTb60SoYBMr3O3yAEkIhMGFmueZgyt9a69Yevkqdvyado HSdrfyO8DPhOMmiODY6J365uZphglypALahpQDL5F2iNFvSQwa2x2DLY/ Ae2NPUJZd4DRjOn6YDSSXy9xrmDI4MVjJtUd+G1x1JQtJl4mlqECvEWkb dS5kMNiDFLRi9qyEA8/f/VcF0gkFlWazHyoqDboQbR7tSVYIC9DboWzNV l1vqfTzl8hqEsM4jM8CEe7XVdTyIyHNWE+WPeCrK0BXn3WuiN7uqYhmXt kR8ECKz5N9NRo4TWNWZcSFn2CqWUU571BKllfc5t19XpkEwL9Dnk8Xh+b w==; X-IronPort-AV: E=McAfee;i="6400,9594,10394"; a="283752679" X-IronPort-AV: E=Sophos;i="5.92,237,1650956400"; d="scan'208";a="283752679" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jul 2022 06:30:10 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,237,1650956400"; d="scan'208";a="648348078" Received: from linux.intel.com ([10.54.29.200]) by fmsmga008.fm.intel.com with ESMTP; 01 Jul 2022 06:30:10 -0700 Received: from abityuts-desk1.fi.intel.com (abityuts-desk1.fi.intel.com [10.237.72.79]) by linux.intel.com (Postfix) with ESMTP id 77F6C580B55; Fri, 1 Jul 2022 06:30:08 -0700 (PDT) Message-ID: Subject: Re: [PATCH] intel_idle: add CPUIDLE_FLAG_IRQ_ENABLE to SPR C1 and C1E From: Artem Bityutskiy To: Jon Kohler , Jacob Pan , Len Brown , "Rafael J. Wysocki" , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 01 Jul 2022 16:30:07 +0300 In-Reply-To: <20220630194309.40465-1-jon@nutanix.com> References: <20220630194309.40465-1-jon@nutanix.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.4 (3.38.4-1.fc33) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jon, On Thu, 2022-06-30 at 15:43 -0400, Jon Kohler wrote: > Add CPUIDLE_FLAG_IRQ_ENABLE to spr_cstates C1 and C1E, which will > allow local IRQs to be enabled during fast idle transitions on SPR. Did you have a chance to measure this? When I was doing this for ICX and CLX, I was using cyclictest and wult for measuring IRQ latency. I was planning to do this for SPR as well. > Note: Enabling this for both C1 and C1E is slightly different than > the approach for SKX/ICX, where CPUIDLE_FLAG_IRQ_ENABLE is only > enabled on C1; however, given that SPR target/exit latency is 1/1 > for c1 and 2/4 for C1E, respectively, which is slower than C1 > for SKX, it seems prudent to now enable it on both states. I was also going to measure this for C1E. Could we please hold on this a bit - I'd like to measure this before we merge it. Artem.