4 files changed, 2 insertions, 131 deletions

diff --git a/Documentation/cpusets.txt b/Documentation/cpusets.txt
index b875d231ac74..ec9de6917f01 100644
--- a/Documentation/cpusets.txt
+++ b/Documentation/cpusets.txt
@@ -87,9 +87,6 @@ This can be especially valuable on:
       and a database), or
     * NUMA systems running large HPC applications with demanding
       performance characteristics.
-    * Also cpu_exclusive cpusets are useful for servers running orthogonal
-      workloads such as RT applications requiring low latency and HPC
-      applications that are throughput sensitive
 
 These subsets, or "soft partitions" must be able to be dynamically
 adjusted, as the job mix changes, without impacting other concurrently
@@ -132,8 +129,6 @@ Cpusets extends these two mechanisms as follows:
  - A cpuset may be marked exclusive, which ensures that no other
    cpuset (except direct ancestors and descendents) may contain
    any overlapping CPUs or Memory Nodes.
-   Also a cpu_exclusive cpuset would be associated with a sched
-   domain.
  - You can list all the tasks (by pid) attached to any cpuset.
 
 The implementation of cpusets requires a few, simple hooks
@@ -145,9 +140,6 @@ into the rest of the kernel, none in performance critical paths:
    allowed in that tasks cpuset.
  - in sched.c migrate_all_tasks(), to keep migrating tasks within
    the CPUs allowed by their cpuset, if possible.
- - in sched.c, a new API partition_sched_domains for handling
-   sched domain changes associated with cpu_exclusive cpusets
-   and related changes in both sched.c and arch/ia64/kernel/domain.c
  - in the mbind and set_mempolicy system calls, to mask the requested
    Memory Nodes by what's allowed in that tasks cpuset.
  - in page_alloc.c, to restrict memory to allowed nodes.
@@ -232,15 +224,6 @@ If a cpuset is cpu or mem exclusive, no other cpuset, other than
 a direct ancestor or descendent, may share any of the same CPUs or
 Memory Nodes.
 
-A cpuset that is cpu_exclusive has a scheduler (sched) domain
-associated with it.  The sched domain consists of all CPUs in the
-current cpuset that are not part of any exclusive child cpusets.
-This ensures that the scheduler load balancing code only balances
-against the CPUs that are in the sched domain as defined above and
-not all of the CPUs in the system. This removes any overhead due to
-load balancing code trying to pull tasks outside of the cpu_exclusive
-cpuset only to be prevented by the tasks' cpus_allowed mask.
-
 A cpuset that is mem_exclusive restricts kernel allocations for
 page, buffer and other data commonly shared by the kernel across
 multiple users.  All cpusets, whether mem_exclusive or not, restrict
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 285ee4827a3c..592e3a55f818 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -729,9 +729,6 @@ struct sched_domain {
 #endif
 };
 
-extern int partition_sched_domains(cpumask_t *partition1,
-                                    cpumask_t *partition2);
-
 #endif  /* CONFIG_SMP */
 
 /*
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index e196510aa40f..0864f4097930 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -755,68 +755,13 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial)
 }
 
 /*
- * For a given cpuset cur, partition the system as follows
- * a. All cpus in the parent cpuset's cpus_allowed that are not part of any
- *    exclusive child cpusets
- * b. All cpus in the current cpuset's cpus_allowed that are not part of any
- *    exclusive child cpusets
- * Build these two partitions by calling partition_sched_domains
- *
- * Call with manage_mutex held.  May nest a call to the
- * lock_cpu_hotplug()/unlock_cpu_hotplug() pair.
- * Must not be called holding callback_mutex, because we must
- * not call lock_cpu_hotplug() while holding callback_mutex.
- */
-
-static void update_cpu_domains(struct cpuset *cur)
-{
-        struct cpuset *c, *par = cur->parent;
-        cpumask_t pspan, cspan;
-
-        if (par == NULL || cpus_empty(cur->cpus_allowed))
-                return;
-
-        /*
-         * Get all cpus from parent's cpus_allowed not part of exclusive
-         * children
-         */
-        pspan = par->cpus_allowed;
-        list_for_each_entry(c, &par->children, sibling) {
-                if (is_cpu_exclusive(c))
-                        cpus_andnot(pspan, pspan, c->cpus_allowed);
-        }
-        if (!is_cpu_exclusive(cur)) {
-                cpus_or(pspan, pspan, cur->cpus_allowed);
-                if (cpus_equal(pspan, cur->cpus_allowed))
-                        return;
-                cspan = CPU_MASK_NONE;
-        } else {
-                if (cpus_empty(pspan))
-                        return;
-                cspan = cur->cpus_allowed;
-                /*
-                 * Get all cpus from current cpuset's cpus_allowed not part
-                 * of exclusive children
-                 */
-                list_for_each_entry(c, &cur->children, sibling) {
-                        if (is_cpu_exclusive(c))
-                                cpus_andnot(cspan, cspan, c->cpus_allowed);
-                }
-        }
-
-        lock_cpu_hotplug();
-        partition_sched_domains(&pspan, &cspan);
-        unlock_cpu_hotplug();
-}
-
-/*
  * Call with manage_mutex held.  May take callback_mutex during call.
  */
 
 static int update_cpumask(struct cpuset *cs, char *buf)
 {
         struct cpuset trialcs;
-        int retval, cpus_unchanged;
+        int retval;
 
         /* top_cpuset.cpus_allowed tracks cpu_online_map; it's read-only */
         if (cs == &top_cpuset)
@@ -843,12 +788,9 @@ static int update_cpumask(struct cpuset *cs, char *buf)
         retval = validate_change(cs, &trialcs);
         if (retval < 0)
                 return retval;
-        cpus_unchanged = cpus_equal(cs->cpus_allowed, trialcs.cpus_allowed);
         mutex_lock(&callback_mutex);
         cs->cpus_allowed = trialcs.cpus_allowed;
         mutex_unlock(&callback_mutex);
-        if (is_cpu_exclusive(cs) && !cpus_unchanged)
-                update_cpu_domains(cs);
         return 0;
 }
 
@@ -1085,7 +1027,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, char *buf)
 {
         int turning_on;
         struct cpuset trialcs;
-        int err, cpu_exclusive_changed;
+        int err;
 
         turning_on = (simple_strtoul(buf, NULL, 10) != 0);
 
@@ -1098,14 +1040,10 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, char *buf)
         err = validate_change(cs, &trialcs);
         if (err < 0)
                 return err;
-        cpu_exclusive_changed =
-                (is_cpu_exclusive(cs) != is_cpu_exclusive(&trialcs));
         mutex_lock(&callback_mutex);
         cs->flags = trialcs.flags;
         mutex_unlock(&callback_mutex);
 
-        if (cpu_exclusive_changed)
-                update_cpu_domains(cs);
         return 0;
 }
 
@@ -1965,17 +1903,6 @@ static int cpuset_mkdir(struct inode *dir, struct dentry *dentry, int mode)
         return cpuset_create(c_parent, dentry->d_name.name, mode | S_IFDIR);
 }
 
-/*
- * Locking note on the strange update_flag() call below:
- *
- * If the cpuset being removed is marked cpu_exclusive, then simulate
- * turning cpu_exclusive off, which will call update_cpu_domains().
- * The lock_cpu_hotplug() call in update_cpu_domains() must not be
- * made while holding callback_mutex.  Elsewhere the kernel nests
- * callback_mutex inside lock_cpu_hotplug() calls.  So the reverse
- * nesting would risk an ABBA deadlock.
- */
-
 static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry)
 {
         struct cpuset *cs = dentry->d_fsdata;
@@ -1995,13 +1922,6 @@ static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry)
                 mutex_unlock(&manage_mutex);
                 return -EBUSY;
         }
-        if (is_cpu_exclusive(cs)) {
-                int retval = update_flag(CS_CPU_EXCLUSIVE, cs, "0");
-                if (retval < 0) {
-                        mutex_unlock(&manage_mutex);
-                        return retval;
-                }
-        }
         parent = cs->parent;
         mutex_lock(&callback_mutex);
         set_bit(CS_REMOVED, &cs->flags);
diff --git a/kernel/sched.c b/kernel/sched.c
index 78c8fbd373a3..0da2b2635c54 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6348,35 +6348,6 @@ static void detach_destroy_domains(const cpumask_t *cpu_map)
         arch_destroy_sched_domains(cpu_map);
 }
 
-/*
- * Partition sched domains as specified by the cpumasks below.
- * This attaches all cpus from the cpumasks to the NULL domain,
- * waits for a RCU quiescent period, recalculates sched
- * domain information and then attaches them back to the
- * correct sched domains
- * Call with hotplug lock held
- */
-int partition_sched_domains(cpumask_t *partition1, cpumask_t *partition2)
-{
-        cpumask_t change_map;
-        int err = 0;
-
-        cpus_and(*partition1, *partition1, cpu_online_map);
-        cpus_and(*partition2, *partition2, cpu_online_map);
-        cpus_or(change_map, *partition1, *partition2);
-
-        /* Detach sched domains from all of the affected cpus */
-        detach_destroy_domains(&change_map);
-        if (!cpus_empty(*partition1))
-                err = build_sched_domains(partition1);
-        if (!err && !cpus_empty(*partition2))
-                err = build_sched_domains(partition2);
-
-        register_sched_domain_sysctl();
-
-        return err;
-}
-
 #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
 static int arch_reinit_sched_domains(void)
 {