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authorPavel Emelyanov <xemul@openvz.org>2007-10-09 07:38:39 +0400
committerDavid S. Miller <davem@sunset.davemloft.net>2007-10-11 03:54:58 +0400
commit4665079cbb2a3e17de82f2ab2940b9f97f37d65e (patch)
tree8e51e9b9e6155eaeccf28783620a07b20a067d8d /include
parentd62a38d1ab350f787e4941e42a3d3e97971e38f5 (diff)
downloadlinux-4665079cbb2a3e17de82f2ab2940b9f97f37d65e.tar.xz
[NETNS]: Move some code into __init section when CONFIG_NET_NS=n
With the net namespaces many code leaved the __init section, thus making the kernel occupy more memory than it did before. Since we have a config option that prohibits the namespace creation, the functions that initialize/finalize some netns stuff are simply not needed and can be freed after the boot. Currently, this is almost not noticeable, since few calls are no longer in __init, but when the namespaces will be merged it will be possible to free more code. I propose to use the __net_init, __net_exit and __net_initdata "attributes" for functions/variables that are not used if the CONFIG_NET_NS is not set to save more space in memory. The exiting functions cannot just reside in the __exit section, as noticed by David, since the init section will have references on it and the compilation will fail due to modpost checks. These references can exist, since the init namespace never dies and the exit callbacks are never called. So I introduce the __exit_refok attribute just like it is already done with the __init_refok. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r--include/linux/init.h1
-rw-r--r--include/net/net_namespace.h9
2 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/init.h b/include/linux/init.h
index 74b1f43bf982..f8d9d0b5cffc 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -57,6 +57,7 @@
* The markers follow same syntax rules as __init / __initdata. */
#define __init_refok noinline __attribute__ ((__section__ (".text.init.refok")))
#define __initdata_refok __attribute__ ((__section__ (".data.init.refok")))
+#define __exit_refok noinline __attribute__ ((__section__ (".exit.text.refok")))
#ifdef MODULE
#define __exit __attribute__ ((__section__(".exit.text"))) __cold
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 934c840b5941..93aa87d32804 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -99,6 +99,15 @@ static inline void release_net(struct net *net)
#define for_each_net(VAR) \
list_for_each_entry(VAR, &net_namespace_list, list)
+#ifdef CONFIG_NET_NS
+#define __net_init
+#define __net_exit
+#define __net_initdata
+#else
+#define __net_init __init
+#define __net_exit __exit_refok
+#define __net_initdata __initdata
+#endif
struct pernet_operations {
struct list_head list;