Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752525AbbFQAgq (ORCPT ); Tue, 16 Jun 2015 20:36:46 -0400 Received: from mail.kernel.org ([198.145.29.136]:54074 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755840AbbFQAgd (ORCPT ); Tue, 16 Jun 2015 20:36:33 -0400 From: Andy Lutomirski To: x86@kernel.org Cc: Borislav Petkov , Peter Zijlstra , John Stultz , linux-kernel@vger.kernel.org, Len Brown , Huang Rui , Denys Vlasenko , kvm@vger.kernel.org, Ralf Baechle , Andy Lutomirski Subject: [PATCH v3 02/18] x86/msr/kvm: Remove vget_cycles() Date: Tue, 16 Jun 2015 17:35:50 -0700 Message-Id: <20615df14ae2eb713ea7a5f5123c1dc4c7ca993d.1434501121.git.luto@kernel.org> X-Mailer: git-send-email 2.4.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1843 Lines: 60 The only caller was kvm's read_tsc. The only difference between vget_cycles and native_read_tsc was that vget_cycles returned zero instead of crashing on TSC-less systems. KVM's already checks vclock_mode before calling that function, so the extra check is unnecessary. (Off-topic, but the whole KVM clock host implementation is gross. IMO it should be rewritten.) Signed-off-by: Andy Lutomirski --- arch/x86/include/asm/tsc.h | 13 ------------- arch/x86/kvm/x86.c | 2 +- 2 files changed, 1 insertion(+), 14 deletions(-) diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h index fd11128faf25..3da1cc1218ac 100644 --- a/arch/x86/include/asm/tsc.h +++ b/arch/x86/include/asm/tsc.h @@ -32,19 +32,6 @@ static inline cycles_t get_cycles(void) return ret; } -static __always_inline cycles_t vget_cycles(void) -{ - /* - * We only do VDSOs on TSC capable CPUs, so this shouldn't - * access boot_cpu_data (which is not VDSO-safe): - */ -#ifndef CONFIG_X86_TSC - if (!cpu_has_tsc) - return 0; -#endif - return (cycles_t)native_read_tsc(); -} - extern void tsc_init(void); extern void mark_tsc_unstable(char *reason); extern int unsynchronized_tsc(void); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 26eaeb522cab..c26faf408bce 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1430,7 +1430,7 @@ static cycle_t read_tsc(void) * but no one has ever seen it happen. */ rdtsc_barrier(); - ret = (cycle_t)vget_cycles(); + ret = (cycle_t)native_read_tsc(); last = pvclock_gtod_data.clock.cycle_last; -- 2.4.2 -- 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/