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 6A76DC38145 for ; Thu, 8 Sep 2022 17:01:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231579AbiIHRB5 (ORCPT ); Thu, 8 Sep 2022 13:01:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231415AbiIHRBv (ORCPT ); Thu, 8 Sep 2022 13:01:51 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 46B8DEA437 for ; Thu, 8 Sep 2022 10:01:44 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 50346153B; Thu, 8 Sep 2022 10:01:50 -0700 (PDT) Received: from [10.1.197.78] (eglon.cambridge.arm.com [10.1.197.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6072E3F71A; Thu, 8 Sep 2022 10:01:41 -0700 (PDT) Message-ID: <751efaec-e997-370a-4ac0-85626c05cf5a@arm.com> Date: Thu, 8 Sep 2022 18:01:32 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 Subject: Re: [PATCH v6 20/21] x86/resctrl: Add resctrl_rmid_realloc_limit to abstract x86's boot_cpu_data Content-Language: en-GB To: haoxin , x86@kernel.org, linux-kernel@vger.kernel.org Cc: Fenghua Yu , Reinette Chatre , Thomas Gleixner , Ingo Molnar , Borislav Petkov , H Peter Anvin , Babu Moger , shameerali.kolothum.thodi@huawei.com, D Scott Phillips OS , lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, Jamie Iles , Cristian Marussi , xingxin.hx@openanolis.org, baolin.wang@linux.alibaba.com References: <20220902154829.30399-1-james.morse@arm.com> <20220902154829.30399-21-james.morse@arm.com> <539cd9b3-9a2b-47c2-7436-89aedef33d1c@linux.alibaba.com> From: James Morse In-Reply-To: <539cd9b3-9a2b-47c2-7436-89aedef33d1c@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Hao Xin, On 07/09/2022 07:26, haoxin wrote: > 在 2022/9/2 下午11:48, James Morse 写道: >> resctrl_rmid_realloc_threshold can be set by user-space. The maximum >> value is specified by the architecture. >> >> Currently max_threshold_occ_write() reads the maximum value from >> boot_cpu_data.x86_cache_size, which is not portable to another >> architecture. >> >> Add resctrl_rmid_realloc_limit to describe the maximum size in bytes >> that user-space can set the threshold to. >> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c >> index e91afe99b763..8d15568d7121 100644 >> --- a/arch/x86/kernel/cpu/resctrl/monitor.c >> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c >> @@ -747,10 +752,10 @@ int rdt_get_mon_l3_config(struct rdt_resource *r) >>   { >>       unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset; >>       struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); >> -    unsigned int cl_size = boot_cpu_data.x86_cache_size; >>       unsigned int threshold; >>       int ret; >>   +    resctrl_rmid_realloc_limit = boot_cpu_data.x86_cache_size * 1024; > Use SZ_1K instead ? Sure, that's usually more readable. I didn't because the existing code doesn't, and I wanted it to be obvious where this had come from. If I re-post the series I'll change this. Thanks for taking a look! James >>       hw_res->mon_scale = boot_cpu_data.x86_cache_occ_scale; >>       r->num_rmid = boot_cpu_data.x86_cache_max_rmid + 1; >>       hw_res->mbm_width = MBM_CNTR_WIDTH_BASE; >> @@ -767,7 +772,7 @@ int rdt_get_mon_l3_config(struct rdt_resource *r) >> * >> * For a 35MB LLC and 56 RMIDs, this is ~1.8% of the LLC. >> */ >> - threshold = cl_size * 1024 / r->num_rmid; >> + threshold = resctrl_rmid_realloc_limit / r->num_rmid; >> /* >> * Because num_rmid may not be a power of two, round the value