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From: James Smart <James.Smart@Emulex.Com>
To: Jayamohan Kalickal <jayamohank@serverengines.com>
Cc: James Bottomley <James.Bottomley@suse.de>,
	Mike Christie <michaelc@cs.wisc.edu>,
	"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
	"sfr@canb.auug.org.au" <sfr@canb.auug.org.au>
Subject: Re: [PATCH 1/1] be2iscsi: Fixes for powerpc compile
Date: Fri, 11 Sep 2009 08:15:42 -0400	[thread overview]
Message-ID: <4AAA3F6E.5030405@emulex.com> (raw)
In-Reply-To: <20090910175417.3c24eb4b@mailhost.serverengines.com>



Jayamohan Kalickal wrote:
> Ok. Reading Mike's comment once again and looking at the lpfc code ,I think, maybe, this is what Mike had in mind, but I could have misunderstood.
> 
> During session create, I will create the pool as well as alloc. This will take 
> care of the allocation at page level and scarce coherent resources problems 
> mentioned by JamesB. Also, this would not have any impact on performance. I see this
> done for "lpfc_mbuf_pool" in lpfc/lpfc_mem.c.
> 
> Thanks
> Jay

As most things - it depends on what's being allocated.  I recommended against 
a pci pool when I was looking at the allocations for queue memory, SGLs, etc 
as that is largely static (allocate/assign once, rarely dealloc/deassign) and 
very much likes to be 4k pages, page aligned, and as contiguous as possible.

However, the DMA buffers for the Command and Response buffers is a different 
story. They are in the fast path, re-alloc per command, are smaller than a 
page, etc and fit the pci pool profile very well.

-- james s


  reply	other threads:[~2009-09-11 12:16 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-09-10 17:54 [PATCH 1/1] be2iscsi: Fixes for powerpc compile Jayamohan Kalickal
2009-09-11 12:15 ` James Smart [this message]
  -- strict thread matches above, loose matches on Subject: below --
2009-09-11 22:54 Jayamohan Kalickal
2009-09-09 19:15 Jayamohan Kalickal
2009-09-10 17:15 ` James Bottomley
     [not found] <20090908223437.cc0c0f82@mailhost.serverengines.com>
2009-09-09 15:38 ` Mike Christie
2009-09-09  1:56 Jayamohan Kallickal
2009-09-08 19:41 Jayamohan Kallickal
2009-09-08 22:20 ` Mike Christie

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