diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/pid.c | 70 |
1 files changed, 64 insertions, 6 deletions
diff --git a/kernel/pid.c b/kernel/pid.c index c6e3f9ffff87..42de9af8c524 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -32,7 +32,6 @@ #define pid_hashfn(nr) hash_long((unsigned long)nr, pidhash_shift) static struct hlist_head *pid_hash; static int pidhash_shift; -static struct kmem_cache *pid_cachep; struct pid init_struct_pid = INIT_STRUCT_PID; int pid_max = PID_MAX_DEFAULT; @@ -176,11 +175,16 @@ static int next_pidmap(struct pid_namespace *pid_ns, int last) fastcall void put_pid(struct pid *pid) { + struct pid_namespace *ns; + if (!pid) return; + + /* FIXME - this must be the namespace this pid lives in */ + ns = &init_pid_ns; if ((atomic_read(&pid->count) == 1) || atomic_dec_and_test(&pid->count)) - kmem_cache_free(pid_cachep, pid); + kmem_cache_free(ns->pid_cachep, pid); } EXPORT_SYMBOL_GPL(put_pid); @@ -208,12 +212,14 @@ struct pid *alloc_pid(void) struct pid *pid; enum pid_type type; int nr = -1; + struct pid_namespace *ns; - pid = kmem_cache_alloc(pid_cachep, GFP_KERNEL); + ns = current->nsproxy->pid_ns; + pid = kmem_cache_alloc(ns->pid_cachep, GFP_KERNEL); if (!pid) goto out; - nr = alloc_pidmap(current->nsproxy->pid_ns); + nr = alloc_pidmap(ns); if (nr < 0) goto out_free; @@ -230,7 +236,7 @@ out: return pid; out_free: - kmem_cache_free(pid_cachep, pid); + kmem_cache_free(ns->pid_cachep, pid); pid = NULL; goto out; } @@ -365,6 +371,56 @@ struct pid *find_ge_pid(int nr) } EXPORT_SYMBOL_GPL(find_get_pid); +struct pid_cache { + int nr_ids; + char name[16]; + struct kmem_cache *cachep; + struct list_head list; +}; + +static LIST_HEAD(pid_caches_lh); +static DEFINE_MUTEX(pid_caches_mutex); + +/* + * creates the kmem cache to allocate pids from. + * @nr_ids: the number of numerical ids this pid will have to carry + */ + +static struct kmem_cache *create_pid_cachep(int nr_ids) +{ + struct pid_cache *pcache; + struct kmem_cache *cachep; + + mutex_lock(&pid_caches_mutex); + list_for_each_entry (pcache, &pid_caches_lh, list) + if (pcache->nr_ids == nr_ids) + goto out; + + pcache = kmalloc(sizeof(struct pid_cache), GFP_KERNEL); + if (pcache == NULL) + goto err_alloc; + + snprintf(pcache->name, sizeof(pcache->name), "pid_%d", nr_ids); + cachep = kmem_cache_create(pcache->name, + /* FIXME add numerical ids here */ + sizeof(struct pid), 0, SLAB_HWCACHE_ALIGN, NULL); + if (cachep == NULL) + goto err_cachep; + + pcache->nr_ids = nr_ids; + pcache->cachep = cachep; + list_add(&pcache->list, &pid_caches_lh); +out: + mutex_unlock(&pid_caches_mutex); + return pcache->cachep; + +err_cachep: + kfree(pcache); +err_alloc: + mutex_unlock(&pid_caches_mutex); + return NULL; +} + struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old_ns) { BUG_ON(!old_ns); @@ -412,5 +468,7 @@ void __init pidmap_init(void) set_bit(0, init_pid_ns.pidmap[0].page); atomic_dec(&init_pid_ns.pidmap[0].nr_free); - pid_cachep = KMEM_CACHE(pid, SLAB_PANIC); + init_pid_ns.pid_cachep = create_pid_cachep(1); + if (init_pid_ns.pid_cachep == NULL) + panic("Can't create pid_1 cachep\n"); } |