Re: [PATCH v2 3/3] percpu: improve allocation success rate for non-GFP_KERNEL callers

[Tahsin Erdogan]

>> Doing preallocations would probably work but not sure if that can be
>> done without
>> complicating code too much. Could you describe what you have in mind?
>
> So, blkg_create() already takes @new_blkg argument which is the
> preallocated blkg and used during q init.  Wouldn't it work to make
> blkg_lookup_create() take @new_blkg too and pass it down to
> blkg_create() (and also free it if it doesn't get used)?  Then,
> blkg_conf_prep() can always (or after a failure with -ENOMEM) allocate
> a new blkg before calling into blkg_lookup_create().  I don't think
> it'll complicate the code path that much.

That makes sense. I will work a patch that does that (unless you are
interested in implementing it yourself).