From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 6CEF0B6EF3 for ; Mon, 30 Apr 2012 15:30:18 +1000 (EST) Message-ID: <1335763810.20866.38.camel@pasglop> Subject: Re: [PATCH] powerpc: Support lower minimum entitlement for virtual processors From: Benjamin Herrenschmidt To: Robert Jennings Date: Mon, 30 Apr 2012 15:30:10 +1000 In-Reply-To: <20120323212213.GB9456@linux.vnet.ibm.com> References: <20120323212213.GB9456@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Cc: linuxppc-dev List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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. > Signed-off-by: Robert Jennings > --- > 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 */