Playing with namespaces and bloat-o-meeter

Serge E. Hallyn serue at us.ibm.com
Wed Sep 26 06:30:19 PDT 2007


Quoting Cedric Le Goater (clg at fr.ibm.com):
> Cedric Le Goater wrote:
> > Serge E. Hallyn wrote:
> >> Quoting Pavel Emelyanov (xemul at openvz.org):
> >>> Hi, guys!
> >>>
> >>> I've noticed that compiling out all the core related to
> >>> cloning and cleaning the new namespace saves us more than
> >>> a Kbyte (!) from the vmlinux.
> >>>
> >>> add/remove: 19/0 grow/shrink: 6/6 up/down: 1532/-336 (1196)
> >>> function                                     old     new   delta
> >>> copy_user_ns                                   -     181    +181
> >>> copy_ipcs                                      -     149    +149
> >>> copy_utsname                                   -     120    +120
> >>> shm_exit_ns                                    -     106    +106
> >>> sem_exit_ns                                    -     106    +106
> >>> msg_exit_ns                                    -     106    +106
> >>> freeary                                        -     100    +100
> >>> release_uids                                   -      95     +95
> >>> freeque                                        -      92     +92
> >>> free_nsproxy                                  48      99     +51
> >>> __sem_init_ns                                  -      45     +45
> >>> shm_init_ns                                    -      42     +42
> >>> sem_init_ns                                    -      42     +42
> >>> msg_init_ns                                    -      42     +42
> >>> __shm_init_ns                                  -      38     +38
> >>> create_new_namespaces                        300     335     +35
> >>> __msg_init_ns                                  -      31     +31
> >>> sysvipc_proc_release                           5      35     +30
> >>> free_ipc_ns                                    -      30     +30
> >>> do_shm_rmid                                    -      29     +29
> >>> shm_release                                   18      39     +21
> >>> free_user_ns                                   -      16     +16
> >>> sysvipc_proc_open                            100     111     +11
> >>> do_shmat                                     778     787      +9
> >>> free_uts_ns                                    -       5      +5
> >>> sys_shmctl                                  1934    1907     -27
> >>> msg_init                                      82      47     -35
> >>> shm_init                                      92      47     -45
> >>> sem_init                                      99      44     -55
> >>> sys_msgctl                                  1394    1311     -83
> >>> sys_semctl                                  2123    2032     -91
> >>>
> >>> Since there already were some questions like "do I need it
> >>> on my cellphone?" in reply to pid namespaces patches and 
> >>> so on, why don't we make ALL the namespaces cloning code 
> >>> under the config option to make those people happy?
> >>>
> >>> Here's the proposed patch.
> >> How about a single config variable for all namespaces?
> > 
> > yes good idea.
> 
> 
> oops, that done already in the patch : CONFIG_NAMESPACES
> 
> thanks :)

That at least organizes them all in Kconfig.  I meant one
config variable, period.

Then instead of adding CONFIG_USER_NS and such whlie they are
experimental, put all experimental namespaces (i.e. maybe soon
user and network) under CONFIG_NAMESPACES_EXPERIMENTAL.

-serge


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