From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752846AbdBIOK6 (ORCPT ); Thu, 9 Feb 2017 09:10:58 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44600 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752637AbdBIOK4 (ORCPT ); Thu, 9 Feb 2017 09:10:56 -0500 From: Vitaly Kuznetsov To: x86@kernel.org, Andy Lutomirski Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Dexuan Cui , linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, virtualization@lists.linux-foundation.org Subject: [PATCH 0/2] x86/vdso: Add Hyper-V TSC page clocksource support Date: Thu, 9 Feb 2017 15:10:50 +0100 Message-Id: <20170209141052.18694-1-vkuznets@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Thu, 09 Feb 2017 14:10:57 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Hyper-V TSC page clocksource is suitable for vDSO, however, the protocol defined by the hypervisor is different from VCLOCK_PVCLOCK. Implemented the required support. Simple sysbench test shows the following results: Before: # time sysbench --test=memory --max-requests=500000 run ... real 1m22.618s user 0m50.193s sys 0m32.268s After: # time sysbench --test=memory --max-requests=500000 run ... real 0m47.241s user 0m47.117s sys 0m0.008s So it seems it is worth it. As nobody seems to be strongly offended by my RFC I'm sending first non-RFC version. Patch 1 is made on top of K. Y.'s code refactoring which moved tsc page clocksource to arch/x86/hyperv/hv_init.c, this is currently present in Greg's char-misc-next tree. Changes since RFC: - Use mul_u64_u64_shr() instead of an open coded implementation [Andy Lutomirski, Thomas Gleixner] - Don't use the same pvclock_page for both VCLOCK_PVCLOCK and VCLOCK_HVCLOCK, create another one [Andy Lutomirski] - Fix issues reported by kbuild test robot. - Rename HYPERV_CLOCK -> HYPERV_TSCPAGE to avoid the ambiguity. I'm also going to try to optimize mul_u64_u64_shr() for 32bit but this can be split from this series I guess. Vitaly Kuznetsov (2): hyperv: implement hv_get_tsc_page() x86/vdso: Add VCLOCK_HVCLOCK vDSO clock read method arch/x86/entry/vdso/vclock_gettime.c | 36 +++++++++++++++++++++++++++++++++++ arch/x86/entry/vdso/vdso-layout.lds.S | 3 ++- arch/x86/entry/vdso/vdso2c.c | 3 +++ arch/x86/entry/vdso/vma.c | 7 +++++++ arch/x86/hyperv/hv_init.c | 12 ++++++++++-- arch/x86/include/asm/clocksource.h | 3 ++- arch/x86/include/asm/mshyperv.h | 8 ++++++++ arch/x86/include/asm/vdso.h | 1 + drivers/hv/Kconfig | 3 +++ 9 files changed, 72 insertions(+), 4 deletions(-) -- 2.9.3