Messages in this thread Patch in this message | | | Date | Fri, 06 Jul 2007 12:09:21 +0400 | From | Pavel Emelianov <> | Subject | [PATCH 11/16] Add support for multiple kmem caches for pids |
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Unike Suka's patches I don not limit the level of pid nesting creating the caches on demand, depending on the namespace's level.
Each kmem cache is names "pid_<NR>", where <NR> is the level of pid namespace and thus - the number of virtual pids in it.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
---
pid.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 files changed, 56 insertions(+), 5 deletions(-)
--- ./kernel/pid.c.ve10 2007-07-06 11:04:15.000000000 +0400 +++ ./kernel/pid.c 2007-07-06 11:04:48.000000000 +0400 @@ -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; @@ -179,11 +178,15 @@ static int next_pidmap(struct pid_namesp fastcall void put_pid(struct pid *pid) { + struct pid_namespace *ns; + if (!pid) return; + + ns = pid->numbers[0].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); @@ -212,7 +215,7 @@ struct pid *alloc_pid(struct pid_namespa enum pid_type type; int nr = -1; - pid = kmem_cache_alloc(pid_cachep, GFP_KERNEL); + pid = kmem_cache_alloc(init_pid_ns.pid_cachep, GFP_KERNEL); if (!pid) goto out; @@ -233,7 +236,7 @@ out: return pid; out_free: - kmem_cache_free(pid_cachep, pid); + kmem_cache_free(init_pid_ns.pid_cachep, pid); pid = NULL; goto out; } @@ -378,6 +381,52 @@ struct pid *find_ge_pid(int nr, struct p } EXPORT_SYMBOL_GPL(find_get_pid); +struct pid_cache { + int level; + char name[16]; + struct kmem_cache *cachep; + struct list_head lh; +}; + +static LIST_HEAD(pid_caches); +static DEFINE_MUTEX(pid_cache_mutex); + +static struct kmem_cache *create_pid_cachep(int level) +{ + struct pid_cache *pc; + struct kmem_cache *cachep = NULL; + + mutex_lock(&pid_cache_mutex); + list_for_each_entry (pc, &pid_caches, lh) + if (pc->level == level) { + cachep = pc->cachep; + goto out; + } + + pc = kzalloc(sizeof(struct pid_cache), GFP_KERNEL); + if (pc == NULL) + goto out; + + snprintf(pc->name, sizeof(pc->name), "pid_%d", level); + cachep = kmem_cache_create(pc->name, + sizeof(struct pid) + level * sizeof(struct pid_number), + 0, SLAB_HWCACHE_ALIGN, NULL, NULL); + if (cachep == NULL) + goto out_free; + + pc->cachep = cachep; + pc->level = level; + list_add(&pc->lh, &pid_caches); + pc = NULL; + +out_free: + if (pc != NULL) + kfree(pc); +out: + mutex_unlock(&pid_cache_mutex); + return cachep; +} + struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old_ns) { BUG_ON(!old_ns); @@ -425,5 +474,7 @@ 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(0); + if (init_pid_ns.pid_cachep == NULL) + panic("Can't create pid cachep"); } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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