On 09/25/2013 05:04 AM, Lin Ming wrote:
> On Wed, Sep 18, 2013 at 8:22 AM, Peter Hurley <peter@hurleysoftware.com> wrote:
> [snip]
>>
>> Looking over vmalloc.c, the critical section footprint of the vmap_area_lock
>> could definitely be reduced (even nearly eliminated), but that's a project
>> for
>> another day :)
>
> Hi Peter,
>
> I also looked over vmallo.c, but didn't find obvious way to reduce the
> critical section footprint.
> Could you share some hints how to do this?

vmap_area_list is an RCU list.
get_vmalloc_info() doesn't need to take the vmap_area_lock at all.
Look at __purge_vmap_area_lazy() for a howto.

Regards,
Peter Hurley