Re: [PATCH 1/1] swiotlb: save io_tlb_used to local variable before leaving critical section

From: Joe Jin
Date: Fri Apr 12 2019 - 10:14:18 EST

I'm good to have this patch, which helps identify the cause of failure is
fragmentation or it really been used up.

On 4/12/19 4:38 AM, Dongli Zhang wrote:
> When swiotlb is full, the kernel would print io_tlb_used. However, the
> result might be inaccurate at that time because we have left the critical
> section protected by spinlock.
> Therefore, we backup the io_tlb_used into local variable before leaving
> critical section.
> Fixes: 83ca25948940 ("swiotlb: dump used and total slots when swiotlb buffer is full")
> Suggested-by: HÃkon Bugge <haakon.bugge@xxxxxxxxxx>
> Signed-off-by: Dongli Zhang <dongli.zhang@xxxxxxxxxx>

Reviewed-by: Joe Jin <joe.jin@xxxxxxxxxx>