Re: [PATCH] mm: add VM_STATIC flag to vmalloc and prevent from removing the areas

[Christoph Hellwig]

On Wed, Apr 12, 2017 at 08:42:08PM +0900, Hoeun Ryu wrote:
> 
> > On Apr 12, 2017, at 3:02 PM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
> > 
> >> On Wed, Apr 12, 2017 at 02:01:59PM +0900, Hoeun Ryu wrote:
> >> vm_area_add_early/vm_area_register_early() are used to reserve vmalloc area
> >> during boot process and those virtually mapped areas are never unmapped.
> >> So `OR` VM_STATIC flag to the areas in vmalloc_init() when importing
> >> existing vmlist entries and prevent those areas from being removed from the
> >> rbtree by accident.
> > 
> > How would they be removed "by accident"?
> 
> I don't mean actual use-cases, but I just want to make it robust against like programming errors.

Oh, ok.  The patch makes sense then, although the changelog could use
a little update.