From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e38.co.us.ibm.com (e38.co.us.ibm.com [32.97.110.159]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e38.co.us.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id A61DDB6FA0 for ; Fri, 11 May 2012 00:55:33 +1000 (EST) Received: from /spool/local by e38.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 10 May 2012 08:55:29 -0600 Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id 90C5019D804E for ; Thu, 10 May 2012 08:55:14 -0600 (MDT) Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q4AEtKNK103584 for ; Thu, 10 May 2012 08:55:22 -0600 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q4AEtGg3001488 for ; Thu, 10 May 2012 08:55:17 -0600 Date: Wed, 9 May 2012 10:56:39 -0500 From: Robert Jennings To: Benjamin Herrenschmidt Subject: Re: [PATCH] powerpc: Support lower minimum entitlement for virtual processors Message-ID: <20120509155639.GA12000@linux.vnet.ibm.com> References: <20120323212213.GB9456@linux.vnet.ibm.com> <1335763810.20866.38.camel@pasglop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1335763810.20866.38.camel@pasglop> Cc: linuxppc-dev List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , * Benjamin Herrenschmidt (benh@kernel.crashing.org) wrote: > 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 ?) Thanks Ben, makes good sense. I'm in the process of validating this and I'll post reply or a new version of the patch when I get it completed. --Rob Jennings > > 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 */ > >