Re: [PATCH] blk-throttle: fix infinite throttling caused by non-cascading timer wheel

From: Jens Axboe
Date: Mon Sep 19 2016 - 17:11:23 EST

On 09/19/2016 03:06 PM, Vivek Goyal wrote:
On Tue, Sep 13, 2016 at 09:46:46AM -0400, Vivek Goyal wrote:

Hi Hou Tao,

[ CC Tejun and Thomas ]

Thanks for the patch. I can reproduce it. I am wondering that why are you
doing so many checks. Can't we just check if throttle group is empty or
not. If it is empty and slice has expired, then start a new slice. If
throttle group is not empty, then we know slice has to be an active slice
and should be extended (despite the fact that it might have expired
because timer function got called later than we expected it to be).

Can you please try following patch. It seems to resolve the issue for me.


Hi Jens,

Can you please pick this patch. It seems to fix the reported issued.
Please let me know if you prefer a separate posting.

I'll apply it, thanks Vivek.

Jens Axboe