Re: [PATCH v2 1/3] mm: vmalloc: Avoid of calling __find_vmap_area() twise in __vunmap()

From: Uladzislau Rezki
Date: Thu Dec 22 2022 - 09:41:39 EST


> A sorry. I need more coffee, this is not the cover letter, but the
> patch that introduceѕ find_unlink_vmap_area.
>
Sorry. I should post it with a cover latter to make it less confusing.

> > - spin_lock(&vmap_area_lock);
> > - unlink_va(va, &vmap_area_root);
> > - spin_unlock(&vmap_area_lock);
> > + if (!list_empty(&va->list)) {
> > + spin_lock(&vmap_area_lock);
> > + unlink_va(va, &vmap_area_root);
> > + spin_unlock(&vmap_area_lock);
> > + }
>
> As mentioned before, I'd much rather move this into the callers.
>
Agree. There is only one caller, it is the free_vmap_block().
Will fix in the v3.

> > + va = find_unlink_vmap_area((unsigned long) addr);
> > + return __remove_vm_area(va);
>
> This can drop the va local variable now.
>
Do you mean like:

struct vm_struct *remove_vm_area(const void *addr)
{
might_sleep();
return __remove_vm_area(
find_unlink_vmap_area((unsigned long) addr));
}

?

Thanks for review!

--
Uladzislau Rezki