From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Subject: Re: [PATCH 00/12] LLD host_lock-less conversion status for .38
Date: Thu, 23 Dec 2010 13:17:18 -0800
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To: adam radford <aradford@gmail.com>
Cc: linux-scsi <linux-scsi@vger.kernel.org>, linux-kernel <linux-kernel@vger.kernel.org>, James Bottomley <James.Bottomley@suse.de>, Jeff Garzik <jeff@garzik.org>, Christoph Hellwig <hch@lst.de>, FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>, Hannes Reinecke <hare@suse.de>, Mike Christie <michaelc@cs.wisc.edu>, Mike Anderson <andmike@linux.vnet.ibm.com>, Tejun Heo <tj@kernel.org>, Vasu Dev <vasu.dev@linux.intel.com>, Tim Chen <tim.c.chen@linux.intel.com>, Andi Kleen <ak@linux.intel.com>, Douglas Gilbert <dgilbert@interlog.com>, Kashyap Desai <Kashyap.Desai@lsi.com>, MPTFusionLinux <DL-MPTFusionLinux@lsi.com>

On Mon, 2010-12-20 at 11:33 -0800, adam radford wrote:
> On Sun, Dec 19, 2010 at 1:21 PM, Nicholas A. Bellinger
> <nab@linux-iscsi.org> wrote:
> > *) megaraid_sas: Running in host_lock-less mode with MSI-X interrupts
> >
> > This has not been tested yet, but I would like to get some review from the LSI
> > megaraid_sas folks now that their patches to enable MSI-X interrupts has been sent
> > to linux-scsi.
> >
> > AdamR, any thoughts or comments to add here..?
> 
> Nick,
> 
> Your patch will not work with the new MegaRAID adapter support I have
> sent in recently.  It requires the build IO path be synchronized with
> map updates with the host_lock.
> 

Adam,

Thanks for the clarification wrt to your latest patches.  Do you think
it would make sense to convert the synchronization between the build IO
path and map updates to use the LLD specific instance->hba_lock instead
of host_lock..?  This is the method I have been employing thus far w/
with the host_lock-less conversion for megaraid_sas, and from a quick
grok it appears this might be the most sane approach for MSI-X support.

Any thoughts..?

Best Regards,

--nab