Message-ID: <4FC63132.60609@ddn.com>
Date: Wed, 30 May 2012 10:39:46 -0400
From: Karandeep Chahal <kchahal@ddn.com>
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To: David Dillow <dillowda@ornl.gov>
CC: "linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "roland@kernel.org" <roland@kernel.org>,
        "sean.hefty@intel.com" <sean.hefty@intel.com>
Subject: Re: [PATCH 1/1] ib_srp: Infiniband srp fast failover patch.
References: <4FC53AAA.3060203@ddn.com> <1338354377.2361.13.camel@obelisk.thedillows.org>
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Hi Dave,

As long as we get faster failover I am happy with Bart's patch.

Currently when I run IO to several luns over multipath and the preferred 
path goes down, the system hangs until the IO fails over. Even ssh'ing 
into the systems take 20-30 seconds. I *suspect* that is because IO is 
being queued up somewhere which brings the whole system to its knees.

Thank you for looking at the patch.

Thanks
Karan

On 05/30/2012 01:06 AM, David Dillow wrote:
> On Tue, 2012-05-29 at 17:07 -0400, Karandeep Chahal wrote:
>> Subject: [PATCH] Infiniband srp fast failover patch.
> This conflicts with Bart's patches to improve failover; it will be much
> better to use his approach to block the target rather than remove it
> wholesale -- we could have lost connectivity as a transient and may get
> it back quickly if someone grabbed the wrong cable, etc.
>
> Also, we should only kill the one target on DREQ, and we already have a
> pointer to it from the CM context -- no need to search.
>
> It is a good idea to hook into the event mechanism; this is something
> I've long wanted to incorporate (as Vu did in OFED). I'm looking at
> getting Bart's series to a point I can merge it, and I'll pull in your
> ideas -- with credit -- there.
>
> Thanks,
--
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