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;
* to continue to serve a useful existence. Next time it's released,
* we will get notified again, if it still has 'notify_on_release' set.
*
- * Note final arg to call_usermodehelper() is 0 - that means
- * don't wait. Since we are holding the global cpuset_sem here,
- * and we are asking another thread (started from keventd) to rmdir a
- * cpuset, we can't wait - or we'd deadlock with the removing thread
- * on cpuset_sem.
+ * The final arg to call_usermodehelper() is 0, which means don't
+ * wait. The separate /sbin/cpuset_release_agent task is forked by
+ * call_usermodehelper(), then control in this thread returns here,
+ * without waiting for the release agent task. We don't bother to
+ * wait because the caller of this routine has no use for the exit
+ * status of the /sbin/cpuset_release_agent task, so no sense holding
+ * our caller up for that.
+ *
+ * The simple act of forking that task might require more memory,
+ * which might need cpuset_sem. So this routine must be called while
+ * cpuset_sem is not held, to avoid a possible deadlock. See also
+ * comments for check_for_release(), below.
*/
-static int cpuset_release_agent(char *cpuset_str)
+static void cpuset_release_agent(const char *pathbuf)
{
char *argv[3], *envp[3];
int i;
+ if (!pathbuf)
+ return;
+
i = 0;
argv[i++] = "/sbin/cpuset_release_agent";
- argv[i++] = cpuset_str;
+ argv[i++] = (char *)pathbuf;
argv[i] = NULL;
i = 0;
envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
envp[i] = NULL;
- return call_usermodehelper(argv[0], argv, envp, 0);
+ call_usermodehelper(argv[0], argv, envp, 0);
+ kfree(pathbuf);
}
/*
* Either cs->count of using tasks transitioned to zero, or the
* cs->children list of child cpusets just became empty. If this
* cs is notify_on_release() and now both the user count is zero and
- * the list of children is empty, send notice to user land.
+ * the list of children is empty, prepare cpuset path in a kmalloc'd
+ * buffer, to be returned via ppathbuf, so that the caller can invoke
+ * cpuset_release_agent() with it later on, once cpuset_sem is dropped.
+ * Call here with cpuset_sem held.
+ *
+ * This check_for_release() routine is responsible for kmalloc'ing
+ * pathbuf. The above cpuset_release_agent() is responsible for
+ * kfree'ing pathbuf. The caller of these routines is responsible
+ * for providing a pathbuf pointer, initialized to NULL, then
+ * calling check_for_release() with cpuset_sem held and the address
+ * of the pathbuf pointer, then dropping cpuset_sem, then calling
+ * cpuset_release_agent() with pathbuf, as set by check_for_release().
*/
-static void check_for_release(struct cpuset *cs)
+static void check_for_release(struct cpuset *cs, char **ppathbuf)
{
if (notify_on_release(cs) && atomic_read(&cs->count) == 0 &&
list_empty(&cs->children)) {
if (!buf)
return;
if (cpuset_path(cs, buf, PAGE_SIZE) < 0)
- goto out;
- cpuset_release_agent(buf);
-out:
- kfree(buf);
+ kfree(buf);
+ else
+ *ppathbuf = buf;
}
}
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.
+ */
+
+/*
+ * Hack to avoid 2.6.13 partial node dynamic sched domain bug.
+ * Disable letting 'cpu_exclusive' cpusets define dynamic sched
+ * domains, until the sched domain can handle partial nodes.
+ * Remove this #if hackery when sched domains fixed.
+ */
+#if 0
+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();
+}
+#else
+static void update_cpu_domains(struct cpuset *cur)
+{
+}
+#endif
+
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);
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)
{
int turning_on;
struct cpuset trialcs;
- int err;
+ int err, cpu_exclusive_changed;
turning_on = (simple_strtoul(buf, NULL, 10) != 0);
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)
+static int attach_task(struct cpuset *cs, char *pidbuf, char **ppathbuf)
{
pid_t pid;
struct task_struct *tsk;
struct cpuset *oldcs;
cpumask_t cpus;
- if (sscanf(buf, "%d", &pid) != 1)
+ if (sscanf(pidbuf, "%d", &pid) != 1)
return -EIO;
if (cpus_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
return -ENOSPC;
put_task_struct(tsk);
if (atomic_dec_and_test(&oldcs->count))
- check_for_release(oldcs);
+ check_for_release(oldcs, ppathbuf);
return 0;
}
struct cftype *cft = __d_cft(file->f_dentry);
cpuset_filetype_t type = cft->private;
char *buffer;
+ char *pathbuf = NULL;
int retval = 0;
/* Crude upper limit on largest legitimate cpulist user might write. */
retval = update_flag(CS_NOTIFY_ON_RELEASE, cs, buffer);
break;
case FILE_TASKLIST:
- retval = attach_task(cs, buffer);
+ retval = attach_task(cs, buffer, &pathbuf);
break;
default:
retval = -EINVAL;
retval = nbytes;
out2:
up(&cpuset_sem);
+ cpuset_release_agent(pathbuf);
out1:
kfree(buffer);
return retval;
struct cpuset *cs = dentry->d_fsdata;
struct dentry *d;
struct cpuset *parent;
+ char *pathbuf = NULL;
/* the vfs holds both inode->i_sem already */
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);
+ check_for_release(parent, &pathbuf);
+ spin_lock(&cs->dentry->d_lock);
d = dget(cs->dentry);
cs->dentry = NULL;
spin_unlock(&d->d_lock);
cpuset_d_remove_dir(d);
dput(d);
up(&cpuset_sem);
+ cpuset_release_agent(pathbuf);
return 0;
}
/**
* cpuset_fork - attach newly forked task to its parents cpuset.
- * @p: pointer to task_struct of forking parent process.
+ * @tsk: pointer to task_struct of forking parent process.
*
* Description: By default, on fork, a task inherits its
- * parents cpuset. The pointer to the shared cpuset is
+ * parent's cpuset. The pointer to the shared cpuset is
* automatically copied in fork.c by dup_task_struct().
* This cpuset_fork() routine need only increment the usage
* counter in that cpuset.
* by the cpuset_sem semaphore. If you don't hold cpuset_sem,
* then a zero cpuset use count is a license to any other task to
* nuke the cpuset immediately.
- *
**/
void cpuset_exit(struct task_struct *tsk)
task_unlock(tsk);
if (notify_on_release(cs)) {
+ char *pathbuf = NULL;
+
down(&cpuset_sem);
if (atomic_dec_and_test(&cs->count))
- check_for_release(cs);
+ check_for_release(cs, &pathbuf);
up(&cpuset_sem);
+ cpuset_release_agent(pathbuf);
} else {
atomic_dec(&cs->count);
}
current->mems_allowed = NODE_MASK_ALL;
}
-/*
+/**
+ * cpuset_update_current_mems_allowed - update mems parameters to new values
+ *
* If the current tasks cpusets mems_allowed changed behind our backs,
* update current->mems_allowed and mems_generation to the new value.
* Do not call this routine if in_interrupt().
}
}
+/**
+ * cpuset_restrict_to_mems_allowed - limit nodes to current mems_allowed
+ * @nodes: pointer to a node bitmap that is and-ed with mems_allowed
+ */
void cpuset_restrict_to_mems_allowed(unsigned long *nodes)
{
bitmap_and(nodes, nodes, nodes_addr(current->mems_allowed),
MAX_NUMNODES);
}
-/*
+/**
+ * cpuset_zonelist_valid_mems_allowed - check zonelist vs. curremt mems_allowed
+ * @zl: the zonelist to be checked
+ *
* Are any of the nodes on zonelist zl allowed in current->mems_allowed?
*/
int cpuset_zonelist_valid_mems_allowed(struct zonelist *zl)
return 0;
}
-/*
- * Is 'current' valid, and is zone z allowed in current->mems_allowed?
+/**
+ * cpuset_zone_allowed - is zone z allowed in current->mems_allowed
+ * @z: zone in question
+ *
+ * Is zone z allowed in current->mems_allowed, or is
+ * the CPU in interrupt context? (zone is always allowed in this case)
*/
int cpuset_zone_allowed(struct zone *z)
{
projects / linux-2.6-omap-h63xx.git / blobdiff