From: Nishanth Aravamudan <nacc@us.ibm.com>
To: David Laight <David.Laight@ACULAB.COM>
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] powerpc: align DTL buffer to AMS boundary
Date: Wed, 13 Apr 2011 08:15:09 -0700 [thread overview]
Message-ID: <20110413151509.GA27602@us.ibm.com> (raw)
In-Reply-To: <AE90C24D6B3A694183C094C60CF0A2F6D8ACF4@saturn3.aculab.com>
On 13.04.2011 [15:59:44 +0100], David Laight wrote:
> > From:
> > linuxppc-dev-bounces+david.laight=aculab.com@lists.ozlabs.org
> > [mailto:linuxppc-dev-bounces+david.laight=aculab.com@lists.ozl
> > abs.org] On Behalf Of Nishanth Aravamudan
> > Sent: 13 April 2011 15:53
> > To: Ben Herrenschmidt
> > Cc: linuxppc-dev@ozlabs.org; Paul Mackerras; Anton Blanchard
> > Subject: [PATCH] powerpc: align DTL buffer to AMS boundary
> >
> > PAPR specifies that DTL buffers can not cross AMS environments (aka
> CMO
> > in the PAPR) and can not cross a memory entitlement granule boundary
> > (4k)....
>
> How big is the buffer being allocated?
> If it is much less than 4k then it might be worth allocating
> a buffer of the correct size, and only if that crosses a 4k boundary
> allocate the larger buffer.
Currently, DISPATCH_LOG_BYTES is 4k (which I assume was actually in
deference to this requirement).
> Also, if the buffer is ever freed, the actual base address is needed
> for the free.
I didn't see any free patch for this sequence of code -- which make
sense as this allocation occurs under a for_each_possible_cpu loop.
Thanks for the feedback,
Nish
next prev parent reply other threads:[~2011-04-13 15:15 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-13 14:59 [PATCH] powerpc: align DTL buffer to AMS boundary David Laight
2011-04-13 15:15 ` Nishanth Aravamudan [this message]
-- strict thread matches above, loose matches on Subject: below --
2011-04-13 14:52 Nishanth Aravamudan
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