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| author | Eric Sandeen <sandeen@redhat.com> | 2008-02-08 04:22:12 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-08 09:22:44 -0800 |
| commit | 2dafe1c4d69345539735cca64250f2d4657bd057 (patch) | |
| tree | a156663f7963869b6f4d6cd4afcc141064fc0329 /fs/namespace.c | |
| parent | ac2a659968f5318a180213f0409c2ea21f072820 (diff) | |
| download | lwn-2dafe1c4d69345539735cca64250f2d4657bd057.tar.gz lwn-2dafe1c4d69345539735cca64250f2d4657bd057.zip | |
reduce large do_mount stack usage with noinlines
do_mount() uses a whopping 616 bytes of stack on x86_64 in 2.6.24-mm1,
largely thanks to gcc inlining the various helper functions.
noinlining these can slim it down a lot; on my box this patch gets it down
to 168, which is mostly the struct nameidata nd; left on the stack.
These functions are called only as do_mount() helpers; none of them should
be in any path that would see a performance benefit from inlining...
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/namespace.c')
| -rw-r--r-- | fs/namespace.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index db51ddc9b671..63ced21c12dc 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -936,8 +936,9 @@ out_unlock: /* * recursively change the type of the mountpoint. + * noinline this do_mount helper to save do_mount stack space. */ -static int do_change_type(struct nameidata *nd, int flag) +static noinline int do_change_type(struct nameidata *nd, int flag) { struct vfsmount *m, *mnt = nd->mnt; int recurse = flag & MS_REC; @@ -960,8 +961,10 @@ static int do_change_type(struct nameidata *nd, int flag) /* * do loopback mount. + * noinline this do_mount helper to save do_mount stack space. */ -static int do_loopback(struct nameidata *nd, char *old_name, int recurse) +static noinline int do_loopback(struct nameidata *nd, char *old_name, + int recurse) { struct nameidata old_nd; struct vfsmount *mnt = NULL; @@ -1010,8 +1013,9 @@ out: * change filesystem flags. dir should be a physical root of filesystem. * If you've mounted a non-root directory somewhere and want to do remount * on it - tough luck. + * noinline this do_mount helper to save do_mount stack space. */ -static int do_remount(struct nameidata *nd, int flags, int mnt_flags, +static noinline int do_remount(struct nameidata *nd, int flags, int mnt_flags, void *data) { int err; @@ -1046,7 +1050,10 @@ static inline int tree_contains_unbindable(struct vfsmount *mnt) return 0; } -static int do_move_mount(struct nameidata *nd, char *old_name) +/* + * noinline this do_mount helper to save do_mount stack space. + */ +static noinline int do_move_mount(struct nameidata *nd, char *old_name) { struct nameidata old_nd, parent_nd; struct vfsmount *p; @@ -1121,8 +1128,9 @@ out: /* * create a new mount for userspace and request it to be added into the * namespace's tree + * noinline this do_mount helper to save do_mount stack space. */ -static int do_new_mount(struct nameidata *nd, char *type, int flags, +static noinline int do_new_mount(struct nameidata *nd, char *type, int flags, int mnt_flags, char *name, void *data) { struct vfsmount *mnt; |