* Re: AHCI_MAX_SG
[not found] <20050609090859.GO5140@suse.de>
@ 2005-08-20 6:45 ` Jeff Garzik
0 siblings, 0 replies; only message in thread
From: Jeff Garzik @ 2005-08-20 6:45 UTC (permalink / raw)
To: Jens Axboe, linux-ide@vger.kernel.org
Jens Axboe wrote:
> Been wondering about this weird value for a while - why does it default
> to 168 segments? As clustering is disabled, that makes 672KiB the
> largest supported request. So currently the dma mapped controller
> command area is about 91KiB in size, I guess the limit is meant to limit
> the size of that area because 256 would be nicer. So how about making it
> 160 which makes the resulting command at least a multiple of 128, or
> even just 128 which gives us a nice clean 512KiB?
(I hope you don't mind me making a private message public -- several
people have asked this, and even you have brought this up in public)
168 is the number that guarantees that AHCI_PORT_PRIV_DMA_SZ is 4K.
No other reason, and, it can (and probably will) be increased in the future.
Jeff
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2005-08-20 6:45 UTC | newest]
Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <20050609090859.GO5140@suse.de>
2005-08-20 6:45 ` AHCI_MAX_SG Jeff Garzik
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).