On 13.04.2011 [15:59:44 +0100], David Laight wrote: > > From: > > linuxppc-dev-bounces+david.laight=aculab....@lists.ozlabs.org > > [mailto:linuxppc-dev-bounces+david.laight=aculab....@lists.ozl > > abs.org] On Behalf Of Nishanth Aravamudan > > Sent: 13 April 2011 15:53 > > To: Ben Herrenschmidt > > Cc: linuxppc-...@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 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev