From nobody Thu Apr 2 14:47:31 2026 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 2344CECAAD5 for ; Fri, 2 Sep 2022 15:58:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236731AbiIBP6N (ORCPT ); Fri, 2 Sep 2022 11:58:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237616AbiIBPz7 (ORCPT ); Fri, 2 Sep 2022 11:55:59 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 076192619 for ; Fri, 2 Sep 2022 08:49:46 -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 B618B1595; Fri, 2 Sep 2022 08:49:52 -0700 (PDT) Received: from merodach.members.linode.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 303053F766; Fri, 2 Sep 2022 08:49:44 -0700 (PDT) From: James Morse To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: Fenghua Yu , Reinette Chatre , Thomas Gleixner , Ingo Molnar , Borislav Petkov , H Peter Anvin , Babu Moger , James Morse , shameerali.kolothum.thodi@huawei.com, D Scott Phillips OS , lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, Jamie Iles , Cristian Marussi , Xin Hao , xingxin.hx@openanolis.org, baolin.wang@linux.alibaba.com Subject: [PATCH v6 20/21] x86/resctrl: Add resctrl_rmid_realloc_limit to abstract x86's boot_cpu_data Date: Fri, 2 Sep 2022 15:48:28 +0000 Message-Id: <20220902154829.30399-21-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20220902154829.30399-1-james.morse@arm.com> References: <20220902154829.30399-1-james.morse@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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. Reviewed-by: Jamie Iles Tested-by: Xin Hao Reviewed-by: Shaopeng Tan Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Reviewed-by: Reinette Chatre Signed-off-by: James Morse --- arch/x86/kernel/cpu/resctrl/monitor.c | 9 +++++++-- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 2 +- include/linux/resctrl.h | 1 + 3 files changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/re= sctrl/monitor.c index e91afe99b763..8d15568d7121 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -67,6 +67,11 @@ unsigned int rdt_mon_features; */ unsigned int resctrl_rmid_realloc_threshold; =20 +/* + * This is the maximum value for the reallocation threshold, in bytes. + */ +unsigned int resctrl_rmid_realloc_limit; + #define CF(cf) ((unsigned long)(1048576 * (cf) + 0.5)) =20 /* @@ -747,10 +752,10 @@ int rdt_get_mon_l3_config(struct rdt_resource *r) { unsigned int mbm_offset =3D boot_cpu_data.x86_cache_mbm_width_offset; struct rdt_hw_resource *hw_res =3D resctrl_to_arch_res(r); - unsigned int cl_size =3D boot_cpu_data.x86_cache_size; unsigned int threshold; int ret; =20 + resctrl_rmid_realloc_limit =3D boot_cpu_data.x86_cache_size * 1024; hw_res->mon_scale =3D boot_cpu_data.x86_cache_occ_scale; r->num_rmid =3D boot_cpu_data.x86_cache_max_rmid + 1; hw_res->mbm_width =3D 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 =3D cl_size * 1024 / r->num_rmid; + threshold =3D resctrl_rmid_realloc_limit / r->num_rmid; =20 /* * Because num_rmid may not be a power of two, round the value diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/r= esctrl/rdtgroup.c index 849bdec37217..e5a48f05e787 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -1059,7 +1059,7 @@ static ssize_t max_threshold_occ_write(struct kernfs_= open_file *of, if (ret) return ret; =20 - if (bytes > (boot_cpu_data.x86_cache_size * 1024)) + if (bytes > resctrl_rmid_realloc_limit) return -EINVAL; =20 resctrl_rmid_realloc_threshold =3D resctrl_arch_round_mon_val(bytes); diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 9995d043650a..cb857f753322 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -251,5 +251,6 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, st= ruct rdt_domain *d, u32 rmid, enum resctrl_event_id eventid); =20 extern unsigned int resctrl_rmid_realloc_threshold; +extern unsigned int resctrl_rmid_realloc_limit; =20 #endif /* _RESCTRL_H */ --=20 2.30.2