From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH 03/13] scsi: unify allocation of scsi command and sense
	buffer
Date: Mon, 25 May 2009 06:42:15 -0400
Message-ID: <20090525104215.GA3191@infradead.org>
References: <1243236668-3398-1-git-send-email-jens.axboe@oracle.com> <1243236668-3398-6-git-send-email-jens.axboe@oracle.com> <20090525074124.GA31746@infradead.org> <20090525074647.GK11363@kernel.dk> <20090525075008.GA23413@infradead.org> <4A1A7406.5060106@panasas.com>
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Cc: Christoph Hellwig <hch@infradead.org>,
	Jens Axboe <jens.axboe@oracle.com>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	chris.mason@oracle.com, david@fromorbit.com,
	akpm@linux-foundation.org, jack@suse.cz,
	yanmin_zhang@linux.intel.com, linux-scsi@vger.kernel.org,
	Matthew Wilcox <matthew@wil.cx>,
	Andi Kleen <andi@firstfloor.org>,
	James Bottomley <James.Bottomley@hansenpartnership.com>
To: Boaz Harrosh <bharrosh@panasas.com>
Return-path: <linux-scsi-owner@vger.kernel.org>
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On Mon, May 25, 2009 at 01:33:42PM +0300, Boaz Harrosh wrote:
> 1. If we have a machine with few type of hosts active each with it's own
> cmnd_slab we end up with many more slabs then today. Even though at the
> end they all happen to be of the same size. (With the pool reserves it
> can get big also).

Note that this should be optional.  Device not having their own
per-command structure would continue using the global pools.  Those
that have their own per-command structures already have their own pools
anyway.

> Hosts specify an size_of_private_command at host template, which might include
> the common-scsi_cmnd + sense_buffer + private_cmnd + optional scsi_ptr +
> bidi_data_buffer + ...

That sounds fine, too.