Re: [PATCH 4/4] rhashtable: fix vmalloc() deadlock in atomic rehash

From: Matthew Wilcox

Date: Fri Oct 30 2026 - 15:11:28 EST


On Fri, Oct 30, 2026 at 10:52:37AM +0100, Uladzislau Rezki wrote:
> The problem with spin_lock_irqsave() is that vmalloc() path can take
> time to alloc and map pages. I am not sure this is worth to switch to
> irq-save locking primitive. So this is the "heaviest" allocator in the
> kernel. Callers have to be careful how the call vmalloc().
>
> IMO, this caller has to be fixed.

Which caller, though? Are you saying rhashtable_insert_rehash()
needs to call kmalloc() instead of kvmalloc()?