add a kmem_cache for nsproxy objects
It should improve performance in some scenarii where a lot of
these nsproxy objects are created by unsharing namespaces. This is
a typical use of virtual servers that are being created or entered.
This is also a good tool to find leaks and gather statistics on
namespace usage.
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 15a6015..4b7fcc8 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -21,6 +21,8 @@
#include <linux/utsname.h>
#include <linux/pid_namespace.h>
+static struct kmem_cache *nsproxy_cachep;
+
struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
static inline void get_nsproxy(struct nsproxy *ns)
@@ -43,9 +45,11 @@
{
struct nsproxy *ns;
- ns = kmemdup(orig, sizeof(struct nsproxy), GFP_KERNEL);
- if (ns)
+ ns = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL);
+ if (ns) {
+ memcpy(ns, orig, sizeof(struct nsproxy));
atomic_set(&ns->count, 1);
+ }
return ns;
}
@@ -109,7 +113,7 @@
if (new_nsp->mnt_ns)
put_mnt_ns(new_nsp->mnt_ns);
out_ns:
- kfree(new_nsp);
+ kmem_cache_free(nsproxy_cachep, new_nsp);
return ERR_PTR(err);
}
@@ -160,7 +164,7 @@
put_pid_ns(ns->pid_ns);
if (ns->user_ns)
put_user_ns(ns->user_ns);
- kfree(ns);
+ kmem_cache_free(nsproxy_cachep, ns);
}
/*
@@ -185,3 +189,12 @@
err = PTR_ERR(*new_nsp);
return err;
}
+
+static int __init nsproxy_cache_init(void)
+{
+ nsproxy_cachep = kmem_cache_create("nsproxy", sizeof(struct nsproxy),
+ 0, SLAB_PANIC, NULL, NULL);
+ return 0;
+}
+
+module_init(nsproxy_cache_init);