From 1426d5a3bd07589534286375998c0c8c6fdc5260 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Thu, 28 Jan 2010 13:23:22 +0000 Subject: powerpc: Dynamically allocate pacas On 64-bit kernels we currently have a 512 byte struct paca_struct for each cpu (usually just called "the paca"). Currently they are statically 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. 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. 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. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/prom.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/powerpc/kernel/prom.c') diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c index 43238b2054b..05131d634e7 100644 --- a/arch/powerpc/kernel/prom.c +++ b/arch/powerpc/kernel/prom.c @@ -43,6 +43,7 @@ #include #include #include +#include #include #include #include @@ -721,6 +722,8 @@ void __init early_init_devtree(void *params) * FIXME .. and the initrd too? */ move_device_tree(); + allocate_pacas(); + DBG("Scanning CPUs ...\n"); /* Retreive CPU related informations from the flat tree -- cgit v1.2.3