2007-01-16 14:28:28

by Cédric Le Goater

Subject: [PATCH -mm] uts namespace : remove CONFIG_UTS_NS

CONFIG_UTS_NS has very little value as it only deactivates the unshare
of the uts namespace and does not improve performance.

Signed-off-by: Cedric Le Goater <[email protected]>
---
include/linux/utsname.h | 19 -------------------
init/Kconfig | 8 --------
kernel/Makefile | 3 +--
kernel/sysctl.c | 3 +--
4 files changed, 2 insertions(+), 31 deletions(-)

Index: 2.6.20-rc4-mm1/include/linux/utsname.h
===================================================================
--- 2.6.20-rc4-mm1.orig/include/linux/utsname.h
+++ 2.6.20-rc4-mm1/include/linux/utsname.h
@@ -48,7 +48,6 @@ static inline void get_uts_ns(struct uts
kref_get(&ns->kref);
}

-#ifdef CONFIG_UTS_NS
extern int unshare_utsname(unsigned long unshare_flags,
struct uts_namespace **new_uts);
extern int copy_utsname(int flags, struct task_struct *tsk);
@@ -58,24 +57,6 @@ static inline void put_uts_ns(struct uts
{
kref_put(&ns->kref, free_uts_ns);
}
-#else
-static inline int unshare_utsname(unsigned long unshare_flags,
- struct uts_namespace **new_uts)
-{
- if (unshare_flags & CLONE_NEWUTS)
- return -EINVAL;
-
- return 0;
-}
-
-static inline int copy_utsname(int flags, struct task_struct *tsk)
-{
- return 0;
-}
-static inline void put_uts_ns(struct uts_namespace *ns)
-{
-}
-#endif

static inline struct new_utsname *utsname(void)
{
Index: 2.6.20-rc4-mm1/init/Kconfig
===================================================================
--- 2.6.20-rc4-mm1.orig/init/Kconfig
+++ 2.6.20-rc4-mm1/init/Kconfig
@@ -205,14 +205,6 @@ config TASK_DELAY_ACCT

Say N if unsure.

-config UTS_NS
- bool "UTS Namespaces"
- default n
- help
- Support uts namespaces. This allows containers, i.e.
- vservers, to use uts namespaces to provide different
- uts info for different servers. If unsure, say N.
-
config AUDIT
bool "Auditing support"
depends on NET
Index: 2.6.20-rc4-mm1/kernel/Makefile
===================================================================
--- 2.6.20-rc4-mm1.orig/kernel/Makefile
+++ 2.6.20-rc4-mm1/kernel/Makefile
@@ -8,7 +8,7 @@ obj-y = sched.o fork.o exec_domain.o
signal.o sys.o kmod.o workqueue.o pid.o \
rcupdate.o extable.o params.o posix-timers.o \
kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
- hrtimer.o rwsem.o latency.o nsproxy.o srcu.o
+ hrtimer.o rwsem.o latency.o nsproxy.o srcu.o utsname.o

obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-y += time/
@@ -48,7 +48,6 @@ obj-$(CONFIG_SECCOMP) += seccomp.o
obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
obj-$(CONFIG_DEBUG_SYNCHRO_TEST) += synchro-test.o
obj-$(CONFIG_RELAY) += relay.o
-obj-$(CONFIG_UTS_NS) += utsname.o
obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o

Index: 2.6.20-rc4-mm1/kernel/sysctl.c
===================================================================
--- 2.6.20-rc4-mm1.orig/kernel/sysctl.c
+++ 2.6.20-rc4-mm1/kernel/sysctl.c
@@ -187,10 +187,9 @@ int sysctl_legacy_va_layout;
static void *get_uts(ctl_table *table, int write)
{
char *which = table->data;
-#ifdef CONFIG_UTS_NS
struct uts_namespace *uts_ns = current->nsproxy->uts_ns;
which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
-#endif
+
if (!write)
down_read(&uts_sem);
else

2007-01-16 15:27:39

by Serge E. Hallyn

Subject: Re: [PATCH -mm] uts namespace : remove CONFIG_UTS_NS

Quoting Cedric Le Goater ([email protected]):
> CONFIG_UTS_NS has very little value as it only deactivates the unshare
> of the uts namespace and does not improve performance.
>
> Signed-off-by: Cedric Le Goater <[email protected]>

It really is worthless complication, with the sole effect being to
complicate testing...

Acked-by: Serge Hallyn <[email protected]>

> ---
> include/linux/utsname.h | 19 -------------------
> init/Kconfig | 8 --------
> kernel/Makefile | 3 +--
> kernel/sysctl.c | 3 +--
> 4 files changed, 2 insertions(+), 31 deletions(-)
>
> Index: 2.6.20-rc4-mm1/include/linux/utsname.h
> ===================================================================
> --- 2.6.20-rc4-mm1.orig/include/linux/utsname.h
> +++ 2.6.20-rc4-mm1/include/linux/utsname.h
> @@ -48,7 +48,6 @@ static inline void get_uts_ns(struct uts
> kref_get(&ns->kref);
> }
>
> -#ifdef CONFIG_UTS_NS
> extern int unshare_utsname(unsigned long unshare_flags,
> struct uts_namespace **new_uts);
> extern int copy_utsname(int flags, struct task_struct *tsk);
> @@ -58,24 +57,6 @@ static inline void put_uts_ns(struct uts
> {
> kref_put(&ns->kref, free_uts_ns);
> }
> -#else
> -static inline int unshare_utsname(unsigned long unshare_flags,
> - struct uts_namespace **new_uts)
> -{
> - if (unshare_flags & CLONE_NEWUTS)
> - return -EINVAL;
> -
> - return 0;
> -}
> -
> -static inline int copy_utsname(int flags, struct task_struct *tsk)
> -{
> - return 0;
> -}
> -static inline void put_uts_ns(struct uts_namespace *ns)
> -{
> -}
> -#endif
>
> static inline struct new_utsname *utsname(void)
> {
> Index: 2.6.20-rc4-mm1/init/Kconfig
> ===================================================================
> --- 2.6.20-rc4-mm1.orig/init/Kconfig
> +++ 2.6.20-rc4-mm1/init/Kconfig
> @@ -205,14 +205,6 @@ config TASK_DELAY_ACCT
>
> Say N if unsure.
>
> -config UTS_NS
> - bool "UTS Namespaces"
> - default n
> - help
> - Support uts namespaces. This allows containers, i.e.
> - vservers, to use uts namespaces to provide different
> - uts info for different servers. If unsure, say N.
> -
> config AUDIT
> bool "Auditing support"
> depends on NET
> Index: 2.6.20-rc4-mm1/kernel/Makefile
> ===================================================================
> --- 2.6.20-rc4-mm1.orig/kernel/Makefile
> +++ 2.6.20-rc4-mm1/kernel/Makefile
> @@ -8,7 +8,7 @@ obj-y = sched.o fork.o exec_domain.o
> signal.o sys.o kmod.o workqueue.o pid.o \
> rcupdate.o extable.o params.o posix-timers.o \
> kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
> - hrtimer.o rwsem.o latency.o nsproxy.o srcu.o
> + hrtimer.o rwsem.o latency.o nsproxy.o srcu.o utsname.o
>
> obj-$(CONFIG_STACKTRACE) += stacktrace.o
> obj-y += time/
> @@ -48,7 +48,6 @@ obj-$(CONFIG_SECCOMP) += seccomp.o
> obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
> obj-$(CONFIG_DEBUG_SYNCHRO_TEST) += synchro-test.o
> obj-$(CONFIG_RELAY) += relay.o
> -obj-$(CONFIG_UTS_NS) += utsname.o
> obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
> obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
>
> Index: 2.6.20-rc4-mm1/kernel/sysctl.c
> ===================================================================
> --- 2.6.20-rc4-mm1.orig/kernel/sysctl.c
> +++ 2.6.20-rc4-mm1/kernel/sysctl.c
> @@ -187,10 +187,9 @@ int sysctl_legacy_va_layout;
> static void *get_uts(ctl_table *table, int write)
> {
> char *which = table->data;
> -#ifdef CONFIG_UTS_NS
> struct uts_namespace *uts_ns = current->nsproxy->uts_ns;
> which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
> -#endif
> +
> if (!write)
> down_read(&uts_sem);
> else

2007-01-22 22:10:00

by Herbert Poetzl

Subject: Re: [PATCH -mm] uts namespace : remove CONFIG_UTS_NS

On Tue, Jan 16, 2007 at 09:27:34AM -0600, Serge E. Hallyn wrote:
> Quoting Cedric Le Goater ([email protected]):
> > CONFIG_UTS_NS has very little value as it only deactivates the unshare
> > of the uts namespace and does not improve performance.
> >
> > Signed-off-by: Cedric Le Goater <[email protected]>
>
> It really is worthless complication, with the sole effect being to
> complicate testing...

we already force that on by default (in Linux-VServer)
and I don't think the code can be considered critical
enough for special casing that ...

so I'm perfectly fine with removing that for UTS

best,
Herbert

> Acked-by: Serge Hallyn <[email protected]>
>
> > ---
> > include/linux/utsname.h | 19 -------------------
> > init/Kconfig | 8 --------
> > kernel/Makefile | 3 +--
> > kernel/sysctl.c | 3 +--
> > 4 files changed, 2 insertions(+), 31 deletions(-)
> >
> > Index: 2.6.20-rc4-mm1/include/linux/utsname.h
> > ===================================================================
> > --- 2.6.20-rc4-mm1.orig/include/linux/utsname.h
> > +++ 2.6.20-rc4-mm1/include/linux/utsname.h
> > @@ -48,7 +48,6 @@ static inline void get_uts_ns(struct uts
> > kref_get(&ns->kref);
> > }
> >
> > -#ifdef CONFIG_UTS_NS
> > extern int unshare_utsname(unsigned long unshare_flags,
> > struct uts_namespace **new_uts);
> > extern int copy_utsname(int flags, struct task_struct *tsk);
> > @@ -58,24 +57,6 @@ static inline void put_uts_ns(struct uts
> > {
> > kref_put(&ns->kref, free_uts_ns);
> > }
> > -#else
> > -static inline int unshare_utsname(unsigned long unshare_flags,
> > - struct uts_namespace **new_uts)
> > -{
> > - if (unshare_flags & CLONE_NEWUTS)
> > - return -EINVAL;
> > -
> > - return 0;
> > -}
> > -
> > -static inline int copy_utsname(int flags, struct task_struct *tsk)
> > -{
> > - return 0;
> > -}
> > -static inline void put_uts_ns(struct uts_namespace *ns)
> > -{
> > -}
> > -#endif
> >
> > static inline struct new_utsname *utsname(void)
> > {
> > Index: 2.6.20-rc4-mm1/init/Kconfig
> > ===================================================================
> > --- 2.6.20-rc4-mm1.orig/init/Kconfig
> > +++ 2.6.20-rc4-mm1/init/Kconfig
> > @@ -205,14 +205,6 @@ config TASK_DELAY_ACCT
> >
> > Say N if unsure.
> >
> > -config UTS_NS
> > - bool "UTS Namespaces"
> > - default n
> > - help
> > - Support uts namespaces. This allows containers, i.e.
> > - vservers, to use uts namespaces to provide different
> > - uts info for different servers. If unsure, say N.
> > -
> > config AUDIT
> > bool "Auditing support"
> > depends on NET
> > Index: 2.6.20-rc4-mm1/kernel/Makefile
> > ===================================================================
> > --- 2.6.20-rc4-mm1.orig/kernel/Makefile
> > +++ 2.6.20-rc4-mm1/kernel/Makefile
> > @@ -8,7 +8,7 @@ obj-y = sched.o fork.o exec_domain.o
> > signal.o sys.o kmod.o workqueue.o pid.o \
> > rcupdate.o extable.o params.o posix-timers.o \
> > kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
> > - hrtimer.o rwsem.o latency.o nsproxy.o srcu.o
> > + hrtimer.o rwsem.o latency.o nsproxy.o srcu.o utsname.o
> >
> > obj-$(CONFIG_STACKTRACE) += stacktrace.o
> > obj-y += time/
> > @@ -48,7 +48,6 @@ obj-$(CONFIG_SECCOMP) += seccomp.o
> > obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
> > obj-$(CONFIG_DEBUG_SYNCHRO_TEST) += synchro-test.o
> > obj-$(CONFIG_RELAY) += relay.o
> > -obj-$(CONFIG_UTS_NS) += utsname.o
> > obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
> > obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
> >
> > Index: 2.6.20-rc4-mm1/kernel/sysctl.c
> > ===================================================================
> > --- 2.6.20-rc4-mm1.orig/kernel/sysctl.c
> > +++ 2.6.20-rc4-mm1/kernel/sysctl.c
> > @@ -187,10 +187,9 @@ int sysctl_legacy_va_layout;
> > static void *get_uts(ctl_table *table, int write)
> > {
> > char *which = table->data;
> > -#ifdef CONFIG_UTS_NS
> > struct uts_namespace *uts_ns = current->nsproxy->uts_ns;
> > which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
> > -#endif
> > +
> > if (!write)
> > down_read(&uts_sem);
> > else
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