Merge /spare/repo/linux-2.6/

[sfrench/cifs-2.6.git] / kernel / cpuset.c

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 00e8f2575512c6159c9a2ad76718f96f308042f5..984c0bf3807fcc7e56bf339c0620205f79e0205b 100644 (file)
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -228,13 +228,7 @@ static struct dentry_operations cpuset_dops = {
 
 static struct dentry *cpuset_get_dentry(struct dentry *parent, const char *name)
 {
-       struct qstr qstr;
-       struct dentry *d;
-
-       qstr.name = name;
-       qstr.len = strlen(name);
-       qstr.hash = full_name_hash(name, qstr.len);
-       d = lookup_hash(&qstr, parent);
+       struct dentry *d = lookup_one_len(name, parent, strlen(name));
        if (!IS_ERR(d))
                d->d_op = &cpuset_dops;
        return d;
@@ -601,10 +595,62 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial)
        return 0;
 }
 
+/*
+ * 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 cpuset_sem held.  May nest a call to the
+ * lock_cpu_hotplug()/unlock_cpu_hotplug() pair.
+ */
+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_removed(cur) || !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();
+}
+
 static int update_cpumask(struct cpuset *cs, char *buf)
 {
        struct cpuset trialcs;
-       int retval;
+       int retval, cpus_unchanged;
 
        trialcs = *cs;
        retval = cpulist_parse(buf, trialcs.cpus_allowed);
@@ -614,9 +660,13 @@ static int update_cpumask(struct cpuset *cs, char *buf)
        if (cpus_empty(trialcs.cpus_allowed))
                return -ENOSPC;
        retval = validate_change(cs, &trialcs);
-       if (retval == 0)
-               cs->cpus_allowed = trialcs.cpus_allowed;
-       return retval;
+       if (retval < 0)
+               return retval;
+       cpus_unchanged = cpus_equal(cs->cpus_allowed, trialcs.cpus_allowed);
+       cs->cpus_allowed = trialcs.cpus_allowed;
+       if (is_cpu_exclusive(cs) && !cpus_unchanged)
+               update_cpu_domains(cs);
+       return 0;
 }
 
 static int update_nodemask(struct cpuset *cs, char *buf)
@@ -652,7 +702,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, char *buf)
 {
        int turning_on;
        struct cpuset trialcs;
-       int err;
+       int err, cpu_exclusive_changed;
 
        turning_on = (simple_strtoul(buf, NULL, 10) != 0);
 
@@ -663,13 +713,18 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, char *buf)
                clear_bit(bit, &trialcs.flags);
 
        err = validate_change(cs, &trialcs);
-       if (err == 0) {
-               if (turning_on)
-                       set_bit(bit, &cs->flags);
-               else
-                       clear_bit(bit, &cs->flags);
-       }
-       return err;
+       if (err < 0)
+               return err;
+       cpu_exclusive_changed =
+               (is_cpu_exclusive(cs) != is_cpu_exclusive(&trialcs));
+       if (turning_on)
+               set_bit(bit, &cs->flags);
+       else
+               clear_bit(bit, &cs->flags);
+
+       if (cpu_exclusive_changed)
+                update_cpu_domains(cs);
+       return 0;
 }
 
 static int attach_task(struct cpuset *cs, char *buf)
@@ -1315,12 +1370,14 @@ static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry)
                up(&cpuset_sem);
                return -EBUSY;
        }
-       spin_lock(&cs->dentry->d_lock);
        parent = cs->parent;
        set_bit(CS_REMOVED, &cs->flags);
+       if (is_cpu_exclusive(cs))
+               update_cpu_domains(cs);
        list_del(&cs->sibling); /* delete my sibling from parent->children */
        if (list_empty(&parent->children))
                check_for_release(parent);
+       spin_lock(&cs->dentry->d_lock);
        d = dget(cs->dentry);
        cs->dentry = NULL;
        spin_unlock(&d->d_lock);