From nobody Mon Apr 6 09:11:32 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 29DEAC001B5 for ; Fri, 2 Sep 2022 15:58:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237574AbiIBP6V (ORCPT ); Fri, 2 Sep 2022 11:58:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237625AbiIBP4J (ORCPT ); Fri, 2 Sep 2022 11:56:09 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6314C643D for ; Fri, 2 Sep 2022 08:49:49 -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 504B11650; Fri, 2 Sep 2022 08:49:55 -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 BF9193F766; Fri, 2 Sep 2022 08:49:46 -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 21/21] x86/resctrl: Make resctrl_arch_rmid_read() return values in bytes Date: Fri, 2 Sep 2022 15:48:29 +0000 Message-Id: <20220902154829.30399-22-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_arch_rmid_read() returns a value in chunks, as read from the hardware. This needs scaling to bytes by mon_scale, as provided by the architecture code. Now that resctrl_arch_rmid_read() performs the overflow and corrections itself, it may as well return a value in bytes directly. This allows the accesses to the architecture specific 'hw' structure to be removed. Move the mon_scale conversion into resctrl_arch_rmid_read(). mbm_bw_count() is updated to calculate bandwidth from bytes. 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 --- Changes since v3: * Only set val in one place in restrl_arch_rmid_read() * Use SZ_1M to improve readability --- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 6 ++---- arch/x86/kernel/cpu/resctrl/internal.h | 4 ++-- arch/x86/kernel/cpu/resctrl/monitor.c | 24 +++++++++++------------ include/linux/resctrl.h | 2 +- 4 files changed, 16 insertions(+), 20 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cp= u/resctrl/ctrlmondata.c index d3f7eb2ac14b..03fc91d8bc9f 100644 --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c @@ -549,7 +549,6 @@ void mon_event_read(struct rmid_read *rr, struct rdt_re= source *r, int rdtgroup_mondata_show(struct seq_file *m, void *arg) { struct kernfs_open_file *of =3D m->private; - struct rdt_hw_resource *hw_res; u32 resid, evtid, domid; struct rdtgroup *rdtgrp; struct rdt_resource *r; @@ -569,8 +568,7 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg) domid =3D md.u.domid; evtid =3D md.u.evtid; =20 - hw_res =3D &rdt_resources_all[resid]; - r =3D &hw_res->r_resctrl; + r =3D &rdt_resources_all[resid].r_resctrl; d =3D rdt_find_domain(r, domid, NULL); if (IS_ERR_OR_NULL(d)) { ret =3D -ENOENT; @@ -584,7 +582,7 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg) else if (rr.err =3D=3D -EINVAL) seq_puts(m, "Unavailable\n"); else - seq_printf(m, "%llu\n", rr.val * hw_res->mon_scale); + seq_printf(m, "%llu\n", rr.val); =20 out: rdtgroup_kn_unlock(of->kn); diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/r= esctrl/internal.h index c05e9b7cf77a..5f7128686cfd 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -279,13 +279,13 @@ struct rftype { =20 /** * struct mbm_state - status for each MBM counter in each domain - * @prev_bw_chunks: Previous chunks value read for bandwidth calculation + * @prev_bw_bytes: Previous bytes value read for bandwidth calculation * @prev_bw: The most recent bandwidth in MBps * @delta_bw: Difference between the current and previous bandwidth * @delta_comp: Indicates whether to compute the delta_bw */ struct mbm_state { - u64 prev_bw_chunks; + u64 prev_bw_bytes; u32 prev_bw; u32 delta_bw; bool delta_comp; diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/re= sctrl/monitor.c index 8d15568d7121..efe0c30d3a12 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -16,6 +16,7 @@ */ =20 #include +#include #include =20 #include @@ -189,7 +190,7 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, stru= ct rdt_domain *d, struct rdt_hw_resource *hw_res =3D resctrl_to_arch_res(r); struct rdt_hw_domain *hw_dom =3D resctrl_to_arch_dom(d); struct arch_mbm_state *am; - u64 msr_val; + u64 msr_val, chunks; =20 if (!cpumask_test_cpu(smp_processor_id(), &d->cpu_mask)) return -EINVAL; @@ -214,12 +215,14 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, st= ruct rdt_domain *d, if (am) { am->chunks +=3D mbm_overflow_count(am->prev_msr, msr_val, hw_res->mbm_width); - *val =3D get_corrected_mbm_count(rmid, am->chunks); + chunks =3D get_corrected_mbm_count(rmid, am->chunks); am->prev_msr =3D msr_val; } else { - *val =3D msr_val; + chunks =3D msr_val; } =20 + *val =3D chunks * hw_res->mon_scale; + return 0; } =20 @@ -232,7 +235,6 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, stru= ct rdt_domain *d, void __check_limbo(struct rdt_domain *d, bool force_free) { struct rdt_resource *r =3D &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; - struct rdt_hw_resource *hw_res =3D resctrl_to_arch_res(r); struct rmid_entry *entry; u32 crmid =3D 1, nrmid; bool rmid_dirty; @@ -255,7 +257,6 @@ void __check_limbo(struct rdt_domain *d, bool force_fre= e) QOS_L3_OCCUP_EVENT_ID, &val)) { rmid_dirty =3D true; } else { - val *=3D hw_res->mon_scale; rmid_dirty =3D (val >=3D resctrl_rmid_realloc_threshold); } =20 @@ -299,7 +300,6 @@ int alloc_rmid(void) static void add_rmid_to_limbo(struct rmid_entry *entry) { struct rdt_resource *r =3D &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; - struct rdt_hw_resource *hw_res =3D resctrl_to_arch_res(r); struct rdt_domain *d; int cpu, err; u64 val =3D 0; @@ -311,7 +311,6 @@ static void add_rmid_to_limbo(struct rmid_entry *entry) err =3D resctrl_arch_rmid_read(r, d, entry->rmid, QOS_L3_OCCUP_EVENT_ID, &val); - val *=3D hw_res->mon_scale; if (err || val <=3D resctrl_rmid_realloc_threshold) continue; } @@ -403,15 +402,14 @@ static int __mon_event_count(u32 rmid, struct rmid_re= ad *rr) */ static void mbm_bw_count(u32 rmid, struct rmid_read *rr) { - struct rdt_hw_resource *hw_res =3D resctrl_to_arch_res(rr->r); struct mbm_state *m =3D &rr->d->mbm_local[rmid]; - u64 cur_bw, chunks, cur_chunks; + u64 cur_bw, bytes, cur_bytes; =20 - cur_chunks =3D rr->val; - chunks =3D cur_chunks - m->prev_bw_chunks; - m->prev_bw_chunks =3D cur_chunks; + cur_bytes =3D rr->val; + bytes =3D cur_bytes - m->prev_bw_bytes; + m->prev_bw_bytes =3D cur_bytes; =20 - cur_bw =3D (chunks * hw_res->mon_scale) >> 20; + cur_bw =3D bytes / SZ_1M; =20 if (m->delta_comp) m->delta_bw =3D abs(cur_bw - m->prev_bw); diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index cb857f753322..0cf5b20c6ddf 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -227,7 +227,7 @@ void resctrl_offline_domain(struct rdt_resource *r, str= uct rdt_domain *d); * @d: domain that the counter should be read from. * @rmid: rmid of the counter to read. * @eventid: eventid to read, e.g. L3 occupancy. - * @val: result of the counter read in chunks. + * @val: result of the counter read in bytes. * * Call from process context on a CPU that belongs to domain @d. * --=20 2.30.2