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Diffstat (limited to 'kernel/pid.c')
-rw-r--r--kernel/pid.c70
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");
}