Date: Mon, 2 Jun 2014 15:02:26 +0200
From: Pavel Machek <pavel@ucw.cz>
To: Tejun Heo <tj@kernel.org>
Cc: Paolo Valente <paolo.valente@unimore.it>, Jens Axboe <axboe@kernel.dk>,
        Li Zefan <lizefan@huawei.com>, Fabio Checconi <fchecconi@gmail.com>,
        Arianna Avanzini <avanzini.arianna@gmail.com>,
        linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org,
        cgroups@vger.kernel.org
Subject: Re: [PATCH RFC - TAKE TWO - 00/12] New version of the BFQ I/O
 Scheduler
Message-ID: <20140602130226.GA14654@amd.pavel.ucw.cz>
References: <20140528221929.GG1419@htj.dyndns.org>
 <1401354343-5527-1-git-send-email-paolo.valente@unimore.it>
 <20140530160712.GG24871@htj.dyndns.org>
 <464F6CBE-A63E-46EF-A90D-BF8450430444@unimore.it>
 <20140530232804.GA5057@htj.dyndns.org>
 <20140602111432.GA3737@amd.pavel.ucw.cz>
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Hi!

> > Well, it's all about how to actually route the changes and in general
> > whenever avoidable we try to avoid whole-sale code replacement
> > especially when most of the structural code is similar like in this
> > case.  Gradually evolving cfq to bfq is likely to take more work but
> > I'm very positive that it'd definitely be a lot easier to merge the
> > changes that way and people involved, including the developers and
> > reviewers, would acquire a lot clearer picture of what's going on in
> > the process.  For example, AFAICS, most of the heuristics added by
> 
> Would it make sense to merge bfq first, _then_ turn cfq into bfq, then
> remove bfq?
> 
> That way
> 
> 1. Users like me would see improvements soon 
> 
> 2. BFQ would get more testing early. 

Like this: I applied patch over today's git... 

I only see last bits of panic...

Call trace:
__bfq_bfqq_expire
bfq_bfqq_expire
bfq_dispatch_requests
sci_request_fn
...
EIP: T.1839+0x26
Kernel panic - not syncing: Fatal exception in interrupt
Shutting down cpus with NMI

...

Will retry.

Any ideas?
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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