Date: Tue, 15 Nov 2016 13:31:10 -0800
From: Shaohua Li <shli@fb.com>
To: Bart Van Assche <bart.vanassche@sandisk.com>
CC: "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "Kernel-team@fb.com" <Kernel-team@fb.com>,
        "axboe@fb.com" <axboe@fb.com>, "tj@kernel.org" <tj@kernel.org>,
        "vgoyal@redhat.com" <vgoyal@redhat.com>
Subject: Re: [PATCH V4 00/15] blk-throttle: add .high limit
Message-ID: <20161115213108.GA28069@shli-mbp.local>
References: <cover.1479161136.git.shli@fb.com>
 <986ada43-3217-3277-724a-5c76f8dad74e@sandisk.com>
 <20161115000529.GA15160@shli-mbp.local>
 <cac5ee16-1400-2fff-3948-fa1dea997702@sandisk.com>
 <20161115004922.GA16173@shli-mbp.local>
 <1bf8605a-9920-19ea-e2ab-2f3d747e55be@sandisk.com>
 <20161115012857.GA17239@shli-mbp.local>
 <6f33c69f-f382-1515-d83d-f1109f982ab3@sandisk.com>
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On Tue, Nov 15, 2016 at 11:53:39AM -0800, Bart Van Assche wrote:
> On 11/14/2016 05:28 PM, Shaohua Li wrote:
> > On Mon, Nov 14, 2016 at 05:18:28PM -0800, Bart Van Assche wrote:
> > > Unless someone can convince me of the opposite I think that coming up with
> > > an algorithm for estimating I/O cost is essential to guarantee I/O fairness
> > > without requesting users to perform complicated parameter configurations.
> > 
> > That's what I tried before:
> > http://marc.info/?l=linux-kernel&m=145617863208940&w=2
> 
> That URL refers to v2 of this patch series. Sorry but I have not found the
> I/O cost estimation algorithm I was referring to in v2 of this patch series.

It's a v2, but not the v2 of this series. There is no algorithm to estimate I/O
cost, that one just uses IOPS or bandwidth to determine I/O cost.

Thanks,
Shaohua