On Fri, 2010-01-22 at 16:19 +1300, Michael Neuling wrote:

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In message <39fb8f1aeab9940b86c940b9a5f8e6bd41ec316c.1263368253.git.micha=

el@ell

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erman.id.au> you wrote:

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On 64-bit kernels we currently have a 512 byte struct paca_struct for
each cpu (usually just called "the paca"). Currently they are staticall=

y

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allocated, which means a kernel built for a large number of cpus will
waste a lot of space if it's booted on a machine with few cpus.
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We can avoid that by only allocating the number of pacas we need at
boot. However this is complicated by the fact that we need to access
the paca before we know how many cpus there are in the system.
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The solution is to dynamically allocate enough space for NR_CPUS pacas,
but then later in boot when we know how many cpus we have, we free any
unused pacas.
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Lightly booted on Legacy iSeries & pSeries LPAR.

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This is broken on 32bit CPUs.  Dies at compile time with
mpc86xx_defconfig.  No paca on 32bit :-(

Bah, who really uses 32-bit anyway ..

Hehe, that's coming from the guy who tested it on iSeries... :-P

Mikey