Re: [PATCH] powerpc: Support lower minimum entitlement for virtual processors
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2012-04-30 05:30:18
On Fri, 2012-03-23 at 16:22 -0500, Robert Jennings wrote:
This patch changes the architecture vector to advertise support for a lower minimum virtual processor entitled capacity. The default minimum without this patch is 10%, this patch specifies 5%. This will allow 20 LPARs per CPU rather than only 10.
Any reason why we don't just put 1% in there and thus don't have to change again when pHyp decides to lower their minimum ? :-) (Can you test that it works, ie, that pHyp doesn't barf if we put 1% and properly uses 5% in that case ?) Cheers, Ben.
quoted hunk ↗ jump to hunk
Signed-off-by: Robert Jennings <redacted> --- arch/powerpc/kernel/prom_init.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-)diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c index eca626e..3d882ea 100644 --- a/arch/powerpc/kernel/prom_init.c +++ b/arch/powerpc/kernel/prom_init.c@@ -689,6 +689,9 @@ static void __init early_cmdline_parse(void) #define OV3_VMX 0x40 /* VMX/Altivec */ #define OV3_DFP 0x20 /* decimal FP */ +/* Option vector 4: IBM PAPR implementation */ +#define OV4_MIN_ENT_CAP 0x05 /* minimum VP entitled capacity */ + /* Option vector 5: PAPR/OF options supported */ #define OV5_LPAR 0x80 /* logical partitioning supported */ #define OV5_SPLPAR 0x40 /* shared-processor LPAR supported */@@ -753,8 +756,9 @@ static unsigned char ibm_architecture_vec[] = { OV3_FP | OV3_VMX | OV3_DFP, /* option vector 4: IBM PAPR implementation */ - 2 - 2, /* length */ + 3 - 2, /* length */ 0, /* don't halt */ + OV4_MIN_ENT_CAP, /* minimum VP entitled capacity */ /* option vector 5: PAPR/OF options */ 13 - 2, /* length */@@ -771,7 +775,7 @@ static unsigned char ibm_architecture_vec[] = { * must match by the macro below. Update the definition if * the structure layout changes. */ -#define IBM_ARCH_VEC_NRCORES_OFFSET 100 +#define IBM_ARCH_VEC_NRCORES_OFFSET 101 W(NR_CPUS), /* number of cores supported */ /* option vector 6: IBM PAPR hints */