Re: [PATCH v4 1/2] mm: refactor __vunmap() to avoid duplicated call to find_vm_area()

[Eric Dumazet]

On 04/18/2019 03:24 PM, Andrew Morton wrote:

> afaict, vfree() will only do a mutex_trylock() in
> try_purge_vmap_area_lazy().  So does vfree actually sleep in any
> situation?  Whether or not local interrupts are enabled?

We would be in a big trouble if vfree() could potentially sleep...

Random example : __free_fdtable() called from rcu callback.