linux-kernel - [PATCH v9 12/13] x86/resctrl: Replace smp_call_function_many() with on_each_cpu

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <166990904972.17806.4220672882391241296.stgit@bmoger-ubuntu>
Date:   Thu, 1 Dec 2022 09:37:29 -0600
From:   Babu Moger <babu.moger@....com>
To:     <corbet@....net>, <reinette.chatre@...el.com>,
        <tglx@...utronix.de>, <mingo@...hat.com>, <bp@...en8.de>
CC:     <fenghua.yu@...el.com>, <dave.hansen@...ux.intel.com>,
        <x86@...nel.org>, <hpa@...or.com>, <paulmck@...nel.org>,
        <akpm@...ux-foundation.org>, <quic_neeraju@...cinc.com>,
        <rdunlap@...radead.org>, <damien.lemoal@...nsource.wdc.com>,
        <songmuchun@...edance.com>, <peterz@...radead.org>,
        <jpoimboe@...nel.org>, <pbonzini@...hat.com>, <babu.moger@....com>,
        <chang.seok.bae@...el.com>, <pawan.kumar.gupta@...ux.intel.com>,
        <jmattson@...gle.com>, <daniel.sneddon@...ux.intel.com>,
        <sandipan.das@....com>, <tony.luck@...el.com>,
        <james.morse@....com>, <linux-doc@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <bagasdotme@...il.com>,
        <eranian@...gle.com>, <christophe.leroy@...roup.eu>,
        <pawan.kumar.gupta@...ux.intel.com>, <jarkko@...nel.org>,
        <adrian.hunter@...el.com>, <quic_jiles@...cinc.com>,
        <peternewman@...gle.com>
Subject: [PATCH v9 12/13] x86/resctrl: Replace smp_call_function_many() with
 on_each_cpu_mask()

The call on_each_cpu_mask() runs the function on each CPU specified
by cpumask, which may include the local processor. So, replace the call
smp_call_function_many() with on_each_cpu_mask() to simplify the code.

Signed-off-by: Babu Moger <babu.moger@....com>
---
 arch/x86/kernel/cpu/resctrl/rdtgroup.c |   29 ++++++++---------------------
 1 file changed, 8 insertions(+), 21 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 6897c480ae55..68e14831a638 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -325,12 +325,7 @@ static void update_cpu_closid_rmid(void *info)
 static void
 update_closid_rmid(const struct cpumask *cpu_mask, struct rdtgroup *r)
 {
-	int cpu = get_cpu();
-
-	if (cpumask_test_cpu(cpu, cpu_mask))
-		update_cpu_closid_rmid(r);
-	smp_call_function_many(cpu_mask, update_cpu_closid_rmid, r, 1);
-	put_cpu();
+	on_each_cpu_mask(cpu_mask, update_cpu_closid_rmid, r, 1);
 }
 
 static int cpus_mon_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
@@ -2135,13 +2130,9 @@ static int set_cache_qos_cfg(int level, bool enable)
 			/* Pick one CPU from each domain instance to update MSR */
 			cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
 	}
-	cpu = get_cpu();
-	/* Update QOS_CFG MSR on this cpu if it's in cpu_mask. */
-	if (cpumask_test_cpu(cpu, cpu_mask))
-		update(&enable);
-	/* Update QOS_CFG MSR on all other cpus in cpu_mask. */
-	smp_call_function_many(cpu_mask, update, &enable, 1);
-	put_cpu();
+
+	/* Update QOS_CFG MSR on all the CPUs in cpu_mask */
+	on_each_cpu_mask(cpu_mask, update, &enable, 1);
 
 	free_cpumask_var(cpu_mask);
 
@@ -2618,7 +2609,7 @@ static int reset_all_ctrls(struct rdt_resource *r)
 	struct msr_param msr_param;
 	cpumask_var_t cpu_mask;
 	struct rdt_domain *d;
-	int i, cpu;
+	int i;
 
 	if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
 		return -ENOMEM;
@@ -2639,13 +2630,9 @@ static int reset_all_ctrls(struct rdt_resource *r)
 		for (i = 0; i < hw_res->num_closid; i++)
 			hw_dom->ctrl_val[i] = r->default_ctrl;
 	}
-	cpu = get_cpu();
-	/* Update CBM on this cpu if it's in cpu_mask. */
-	if (cpumask_test_cpu(cpu, cpu_mask))
-		rdt_ctrl_update(&msr_param);
-	/* Update CBM on all other cpus in cpu_mask. */
-	smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1);
-	put_cpu();
+
+	/* Update CBM on all the CPUs in cpu_mask */
+	on_each_cpu_mask(cpu_mask, rdt_ctrl_update, &msr_param, 1);
 
 	free_cpumask_var(cpu_mask);