From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762354AbbA3ODe (ORCPT ); Fri, 30 Jan 2015 09:03:34 -0500 Received: from e06smtp11.uk.ibm.com ([195.75.94.107]:43764 "EHLO e06smtp11.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762307AbbA3ODc (ORCPT ); Fri, 30 Jan 2015 09:03:32 -0500 From: Philipp Hachtmann To: mingo@redhat.com, peterz@infradead.org, linux-kernel@vger.kernel.org Cc: heiko.carstens@de.ibm.com, linux-s390@vger.kernel.org, schwidefsky@de.ibm.com, Philipp Hachtmann Subject: [PATCH 3/3] s390/cputime: SMT based scaling of CPU runtime deltas Date: Fri, 30 Jan 2015 15:02:42 +0100 Message-Id: <1422626562-6966-4-git-send-email-phacht@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1422626562-6966-1-git-send-email-phacht@linux.vnet.ibm.com> References: <1422626562-6966-1-git-send-email-phacht@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15013014-0041-0000-0000-0000032545D1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The scheduler calculates CPU runtime deltas to account for a task's runtime. These deltas have to be adapted on SMT CPUs to reflect the real processing power consumed during the last delta. This patch introduces scale_rq_clock_delta which is used by the scheduler to scale the calculated delta by an SMT based factor. Signed-off-by: Philipp Hachtmann --- arch/s390/include/asm/cputime.h | 17 ++++++++++++++++- arch/s390/kernel/vtime.c | 4 ++-- 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/arch/s390/include/asm/cputime.h b/arch/s390/include/asm/cputime.h index fee50dd..e44f285 100644 --- a/arch/s390/include/asm/cputime.h +++ b/arch/s390/include/asm/cputime.h @@ -8,6 +8,8 @@ #define _S390_CPUTIME_H #include +#include +#include #include #define CPUTIME_PER_USEC 4096ULL @@ -20,6 +22,9 @@ typedef unsigned long long __nocast cputime64_t; #define cmpxchg_cputime(ptr, old, new) cmpxchg64(ptr, old, new) +DECLARE_PER_CPU(u64, mt_scaling_mult); +DECLARE_PER_CPU(u64, mt_scaling_div); + static inline unsigned long __div(unsigned long long n, unsigned long base) { #ifndef CONFIG_64BIT @@ -172,6 +177,7 @@ static inline clock_t cputime64_to_clock_t(cputime64_t cputime) * * Returns an incrementing time stamp in ns. */ +#define cpu_exec_time cpu_exec_time static inline u64 cpu_exec_time(int cpu_unused) { u64 timer; @@ -181,7 +187,16 @@ static inline u64 cpu_exec_time(int cpu_unused) return ((ULLONG_MAX - timer) * 1000) / 4096; } -#define cpu_exec_time cpu_exec_time + +#define scale_rq_clock_delta scale_rq_clock_delta +static inline void scale_rq_clock_delta(u64 *delta) +{ + u64 mult = __get_cpu_var(mt_scaling_mult); + u64 div = __get_cpu_var(mt_scaling_div); + + if (smp_cpu_mtid) + *delta = (*delta * mult) / div; +} cputime64_t arch_cpu_idle_time(int cpu); diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c index 97b3c12..5d9bbd0 100644 --- a/arch/s390/kernel/vtime.c +++ b/arch/s390/kernel/vtime.c @@ -26,8 +26,8 @@ static atomic64_t virt_timer_current; static atomic64_t virt_timer_elapsed; static DEFINE_PER_CPU(u64, mt_cycles[32]); -static DEFINE_PER_CPU(u64, mt_scaling_mult) = { 1 }; -static DEFINE_PER_CPU(u64, mt_scaling_div) = { 1 }; +DEFINE_PER_CPU(u64, mt_scaling_mult) = { 1 }; +DEFINE_PER_CPU(u64, mt_scaling_div) = { 1 }; static inline u64 get_vtimer(void) { -- 2.1.4