lkml.org 
[lkml]   [2018]   [Apr]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH V3 27/39] x86/intel_rdt: Add utilities to test pseudo-locked region possibility
Date
A pseudo-locked region does not have a class of service associated with
it and thus not tracked in the array of control values maintained as
part of the domain. Even so, when the user provides a new bitmask for
another resource group it needs to be checked for interference with
existing pseudo-locked regions.

Additionally only one pseudo-locked region can be created in any cache
hierarchy.

Introduce two utilities in support of above scenarios: (1) a utility
that can be used to test if a given capacity bitmask overlaps with any
pseudo-locked regions associated with a particular cache instance, (2) a
utility that can be used to test if a pseudo-locked region exists within
a particular cache hierarchy.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
arch/x86/kernel/cpu/intel_rdt.h | 2 ++
arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c | 55 +++++++++++++++++++++++++++++
2 files changed, 57 insertions(+)

diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index 102eab32ee3e..acc08b850f41 100644
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -488,6 +488,8 @@ enum rdtgrp_mode rdtgroup_mode_by_closid(int closid);
int rdtgroup_tasks_assigned(struct rdtgroup *r);
int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp);
int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp);
+bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_domain *d, u32 _cbm);
+bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_domain *d);
struct rdt_domain *get_domain_from_cpu(int cpu, struct rdt_resource *r);
int update_domains(struct rdt_resource *r, int closid);
void closid_free(int closid);
diff --git a/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c b/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c
index 3242ccb0d952..ad1da2ff096f 100644
--- a/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c
+++ b/arch/x86/kernel/cpu/intel_rdt_pseudo_lock.c
@@ -307,3 +307,58 @@ int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp)
pseudo_lock_free(rdtgrp);
return 0;
}
+
+/**
+ * rdtgroup_cbm_overlaps_pseudo_locked - Test if CBM or portion is pseudo-locked
+ * @d: RDT domain
+ * @_cbm: CBM to test
+ *
+ * @d represents a cache instance and @_cbm a capacity bitmask that is
+ * considered for it. Determine if @_cbm overlaps with any existing
+ * pseudo-locked region on @d.
+ *
+ * Return: true if @_cbm overlaps with pseudo-locked region on @d, false
+ * otherwise.
+ */
+bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_domain *d, u32 _cbm)
+{
+ unsigned long *cbm = (unsigned long *)&_cbm;
+ unsigned long *cbm_b;
+ unsigned int cbm_len;
+
+ if (d->plr) {
+ cbm_len = d->plr->r->cache.cbm_len;
+ cbm_b = (unsigned long *)&d->plr->cbm;
+ if (bitmap_intersects(cbm, cbm_b, cbm_len))
+ return true;
+ }
+
+ return false;
+}
+
+/**
+ * rdtgroup_pseudo_locked_in_hierarchy - Pseudo-locked region in cache hierarchy
+ * @d: RDT domain under test
+ *
+ * The setup of a pseudo-locked region affects all cache instances within
+ * the hierarchy of the region. It is thus essential to know if any
+ * pseudo-locked regions exist within a cache hierarchy to prevent any
+ * attempts to create new pseudo-locked regions in the same hierarchy.
+ *
+ * Return: true if a pseudo-locked region exists in the hierarchy of @d,
+ * false otherwise.
+ */
+bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_domain *d)
+{
+ struct rdt_resource *r;
+ struct rdt_domain *d_i;
+
+ for_each_alloc_enabled_rdt_resource(r) {
+ list_for_each_entry(d_i, &r->domains, list) {
+ if (d_i != d &&
+ cpumask_intersects(&d_i->cpu_mask, &d->cpu_mask))
+ return true;
+ }
+ }
+ return false;
+}
--
2.13.6
\
 
 \ /
  Last update: 2018-04-25 20:19    [W:0.131 / U:12.256 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site