diff options
Diffstat (limited to 'kernel/cpuset.c')
| -rw-r--r-- | kernel/cpuset.c | 123 |
1 files changed, 96 insertions, 27 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 00e8f257551..805fb909731 100644 --- 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); @@ -1383,10 +1440,10 @@ void __init cpuset_init_smp(void) /** * 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. @@ -1414,7 +1471,6 @@ void cpuset_fork(struct task_struct *tsk) * 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) @@ -1464,7 +1520,9 @@ void cpuset_init_current_mems_allowed(void) 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(). @@ -1483,13 +1541,20 @@ void cpuset_update_current_mems_allowed(void) } } +/** + * 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) @@ -1505,8 +1570,12 @@ 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) { |