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Date: Sat, 13 Jan 2018 14:02:58 +0100
From: Oleksandr Natalenko <oleksandr@natalenko.name>
To: Paolo Valente <paolo.valente@linaro.org>
Cc: Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, ulf.hansson@linaro.org,
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Subject: Re: [PATCH BUGFIX/IMPROVEMENT 0/2] block, bfq: two pending patches
In-Reply-To: <20180113110518.2519-1-paolo.valente@linaro.org>
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Hi.

13.01.2018 12:05, Paolo Valente wrote:
> Hi Jens,
> here are again the two pending patches you asked me to resend [1]. One
> of them, fixing read-starvation problems, was accompanied by a cover
> letter. I'm pasting the content of that cover letter below.
> 
> The patch addresses (serious) starvation problems caused by
> request-tag exhaustion, as explained in more detail in the commit
> message. I started from the solution in the function
> kyber_limit_depth, but then I had to define more articulate limits, to
> counter starvation also in cases not covered in kyber_limit_depth.
> If this solution proves to be effective, I'm willing to port it
> somehow to the other schedulers.
> 
> Thanks,
> Paolo
> 
> [1] https://www.spinics.net/lists/linux-block/msg21586.html
> 
> Paolo Valente (2):
>   block, bfq: limit tags for writes and async I/O
>   block, bfq: limit sectors served with interactive weight raising
> 
>  block/bfq-iosched.c | 158 
> +++++++++++++++++++++++++++++++++++++++++++++++++---
>  block/bfq-iosched.h |  17 ++++++
>  block/bfq-wf2q.c    |   3 +
>  3 files changed, 169 insertions(+), 9 deletions(-)
> 
> --
> 2.15.1

I'm running the system with these patches since the end of December, so 
with regard to stability and visible smoke:

Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>

for both of them.

Many thanks, Paolo!