Re: [patch 1/3] mmu_notifier: Core code

[Christoph Lameter]

On Thu, 31 Jan 2008, Jack Steiner wrote:

> I currently unlink the mmu_notifier when the last GRU mapping is closed. For
> example, if a user does a:
> 
>         gru_create_context();
>         ...
>         gru_destroy_context();
> 
> the mmu_notifier is unlinked and all task tables allocated
> by the driver are freed. Are you suggesting that I leave tables
> allocated until the task terminates??

You are in user space and calling into the kernel somehow. The 
mmap_sem is not held at that point so its no trouble to use the unregister 
function. After that wait for rcu and then free your tables.

> I assumed that I would need to use call_rcu() or synchronize_rcu()
> before the table is actually freed. That's still on my TODO list.

Right.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/