Re: [PATCH 4/5] shmem: use call_once()

Akinobu Mita
2008-03-11T12:29:27Z

2008/3/11, Hugh Dickins <hugh@veritas.com>:
> On Tue, 11 Mar 2008, Akinobu Mita wrote:
> > This patch defers mounting tmpfs till shmem_file_setup() is
> > called first time by using call_once().
>
>
> Please explain why we might need this patch: is something changing
> elsewhere? Or are you misled by that "module_init(init_tmpfs)"
> into thinking that mm/shmem.c is sometimes built modular?
>

If no processes call shmem_file_setup() (via shm_get(2)), it is unnecessary
to do vfs_kern_mount(&tmpfs_fs_type, ...) unconditionary in boot-time.
So I thought it is suitable example to demonstrate how to use "call_once()"
in this patch set.