Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933572Ab0HNQUL (ORCPT ); Sat, 14 Aug 2010 12:20:11 -0400 Received: from smtp-outbound-1.vmware.com ([65.115.85.69]:10666 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757027Ab0HNQUK convert rfc822-to-8bit (ORCPT ); Sat, 14 Aug 2010 12:20:10 -0400 From: Alok Kataria To: Sven Joachim CC: Greg KH , "linux-kernel@vger.kernel.org" , "stable@kernel.org" , "stable-review@kernel.org" , "torvalds@linux-foundation.org" , "akpm@linux-foundation.org" , "alan@lxorguk.ukuu.org.uk" , "H. Peter Anvin" Date: Sat, 14 Aug 2010 09:21:08 -0700 Subject: Re: [01/54] x86, vmware: Preset lpj values when on VMware. Thread-Topic: [01/54] x86, vmware: Preset lpj values when on VMware. Thread-Index: Acs7zI+cjieHwsGQQQiO18HbvuxssA== Message-ID: <70C34ED6-B722-4577-A124-A3E6CD0F4440@vmware.com> References: <20100812000249.GA30948@kroah.com> <20100812000123.413199056@clark.site> <8739uho03t.fsf@turtle.gmx.de> In-Reply-To: <8739uho03t.fsf@turtle.gmx.de> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2513 Lines: 78 On Aug 14, 2010, at 5:22 AM, "Sven Joachim" wrote: > On 2010-08-12 02:00 +0200, Greg KH wrote: > >> 2.6.34-stable review patch. If anyone has any objections, please let us know. > > Sorry for being a bit late -- I didn't get around to build 2.6.34.4-rc1 > in time. :-( > >> From: Alok Kataria >> >> commit 9f242dc10e0c3c1eb32d8c83c18650a35fd7f80d upstream. >> >> When running on VMware's platform, we have seen situations where >> the AP's try to calibrate the lpj values and fail to get good calibration >> runs becasue of timing issues. As a result delays don't work correctly >> on all cpus. >> >> The solutions is to set preset_lpj value based on the current tsc frequency >> value. This is similar to what KVM does as well. >> >> Signed-off-by: Alok N Kataria >> LKML-Reference: <1280790637.14933.29.camel@ank32.eng.vmware.com> >> Signed-off-by: H. Peter Anvin >> Signed-off-by: Greg Kroah-Hartman >> >> --- >> arch/x86/kernel/cpu/vmware.c | 9 ++++++++- >> 1 file changed, 8 insertions(+), 1 deletion(-) >> >> --- a/arch/x86/kernel/cpu/vmware.c >> +++ b/arch/x86/kernel/cpu/vmware.c >> @@ -51,7 +51,7 @@ static inline int __vmware_platform(void >> >> static unsigned long vmware_get_tsc_khz(void) >> { >> - uint64_t tsc_hz; >> + uint64_t tsc_hz, lpj; >> uint32_t eax, ebx, ecx, edx; >> >> VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); >> @@ -62,6 +62,13 @@ static unsigned long vmware_get_tsc_khz( >> printk(KERN_INFO "TSC freq read from hypervisor : %lu.%03lu MHz\n", >> (unsigned long) tsc_hz / 1000, >> (unsigned long) tsc_hz % 1000); >> + >> + if (!preset_lpj) { >> + lpj = ((u64)tsc_hz * 1000); >> + do_div(lpj, HZ); > > This led to a build failure for me because HZ is not defined in the > attached configuration. Note that this problem did not show up in > 2.6.35.2 with a very similar .config file. You might want to include jiffies.h in this file. Can you please check if this is needed for 2.6.33-stable too ? AFAIK 2.6.32 already has it. Thanks, Alok > >> + preset_lpj = lpj; >> + } >> + >> return tsc_hz; >> } > > Regards, > Sven > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/