Commit 47820e73 authored by Xiaochen Shen's avatar Xiaochen Shen Committed by Borislav Petkov
Browse files

x86/resctrl: Initialize a new resource group with default MBA values 



Currently, when a new resource group is created, the allocation values
of the MBA resource are not initialized and remain meaningless data.

For example:

  mkdir /sys/fs/resctrl/p1
  cat /sys/fs/resctrl/p1/schemata
  MB:0=100;1=100

  echo "MB:0=10;1=20" > /sys/fs/resctrl/p1/schemata
  cat /sys/fs/resctrl/p1/schemata
  MB:0= 10;1= 20

  rmdir /sys/fs/resctrl/p1
  mkdir /sys/fs/resctrl/p2
  cat /sys/fs/resctrl/p2/schemata
  MB:0= 10;1= 20

Therefore, when the new group is created, it is reasonable to initialize
MBA resource with default values.

Initialize the MBA resource and cache resources in separate functions.

 [ bp: Add newlines between code blocks for better readability. ]

Signed-off-by: default avatarXiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: pei.p.jia@intel.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/1555499329-1170-3-git-send-email-xiaochen.shen@intel.com
parent 7390619a

arch/x86/kernel/cpu/resctrl/ctrlmondata.c

+2 −2
Original line number Diff line number Diff line
@@ -342,10 +342,10 @@ int update_domains(struct rdt_resource *r, int closid) 
	if (cpumask_empty(cpu_mask) || mba_sc)

		goto done;

	cpu = get_cpu();

	/* Update CBM on this cpu if it's in cpu_mask. */

	/* Update resource control msr on this CPU if it's in cpu_mask. */

	if (cpumask_test_cpu(cpu, cpu_mask))

		rdt_ctrl_update(&msr_param);

	/* Update CBM on other cpus. */

	/* Update resource control msr on other CPUs. */

	smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1);

	put_cpu();

arch/x86/kernel/cpu/resctrl/rdtgroup.c

+33 −19
Original line number Diff line number Diff line
@@ -2581,8 +2581,8 @@ static int __init_one_rdt_domain(struct rdt_domain *d, struct rdt_resource *r, 
	return 0;

}



/**

 * rdtgroup_init_alloc - Initialize the new RDT group's allocations

/*

 * Initialize cache resources with default values.

 *

 * A new RDT group is being created on an allocation capable (CAT)

 * supporting system. Set this group up to start off with all usable
@@ -2591,38 +2591,52 @@ static int __init_one_rdt_domain(struct rdt_domain *d, struct rdt_resource *r, 
 * If there are no more shareable bits available on any domain then

 * the entire allocation will fail.

 */

static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)

static int rdtgroup_init_cat(struct rdt_resource *r, u32 closid)

{

	struct rdt_resource *r;

	struct rdt_domain *d;

	int ret;



	for_each_alloc_enabled_rdt_resource(r) {

		/*

		 * Only initialize default allocations for CBM cache

		 * resources

		 */

		if (r->rid == RDT_RESOURCE_MBA)

			continue;

	list_for_each_entry(d, &r->domains, list) {

			ret = __init_one_rdt_domain(d, r, rdtgrp->closid);

		ret = __init_one_rdt_domain(d, r, closid);

		if (ret < 0)

			return ret;

	}



	return 0;

}



/* Initialize MBA resource with default values. */

static void rdtgroup_init_mba(struct rdt_resource *r)

{

	struct rdt_domain *d;



	list_for_each_entry(d, &r->domains, list) {

		d->new_ctrl = is_mba_sc(r) ? MBA_MAX_MBPS : r->default_ctrl;

		d->have_new_ctrl = true;

	}

}



/* Initialize the RDT group's allocations. */

static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)

{

	struct rdt_resource *r;

	int ret;



	for_each_alloc_enabled_rdt_resource(r) {

		/*

		 * Only initialize default allocations for CBM cache

		 * resources

		 */

		if (r->rid == RDT_RESOURCE_MBA)

			continue;

		if (r->rid == RDT_RESOURCE_MBA) {

			rdtgroup_init_mba(r);

		} else {

			ret = rdtgroup_init_cat(r, rdtgrp->closid);

			if (ret < 0)

				return ret;

		}



		ret = update_domains(r, rdtgrp->closid);

		if (ret < 0) {

			rdt_last_cmd_puts("Failed to initialize allocations\n");

			return ret;

		}



	}



	rdtgrp->mode = RDT_MODE_SHAREABLE;

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