From: Jens Axboe <axboe@kernel.dk>
To: Paolo Valente <paolo.valente@linaro.org>
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
ulf.hansson@linaro.org, broonie@kernel.org,
linus.walleij@linaro.org, bfq-iosched@googlegroups.com,
oleksandr@natalenko.name
Subject: Re: [PATCH BUGFIX/IMPROVEMENT 0/2] block, bfq: two pending patches
Date: Thu, 18 Jan 2018 08:23:12 -0700 [thread overview]
Message-ID: <55d37f66-019d-2ded-2559-16930466d644@kernel.dk> (raw)
In-Reply-To: <20180113110518.2519-1-paolo.valente@linaro.org>
On 1/13/18 4:05 AM, 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.
It's something we've been doing in the old request layer for tagging for
a long time (more than a decade), so a generic (and fast) solution that
covers all cases for blk-mq-tag would indeed be great.
For now, I have applied these for 4.16, thanks.
--
Jens Axboe
prev parent reply other threads:[~2018-01-18 15:23 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-13 11:05 [PATCH BUGFIX/IMPROVEMENT 0/2] block, bfq: two pending patches Paolo Valente
2018-01-13 11:05 ` [PATCH BUGFIX/IMPROVEMENT 1/2] block, bfq: limit tags for writes and async I/O Paolo Valente
2018-01-13 11:05 ` [PATCH BUGFIX/IMPROVEMENT 2/2] block, bfq: limit sectors served with interactive weight raising Paolo Valente
2018-01-13 13:02 ` [PATCH BUGFIX/IMPROVEMENT 0/2] block, bfq: two pending patches Oleksandr Natalenko
2018-01-18 8:25 ` Paolo Valente
2018-01-18 15:23 ` Jens Axboe [this message]
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