From patchwork Wed Feb 8 23:58:36 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Antipov X-Patchwork-Id: 6715 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id 667B723ECC for ; Wed, 8 Feb 2012 23:57:40 +0000 (UTC) Received: from mail-iy0-f180.google.com (mail-iy0-f180.google.com [209.85.210.180]) by fiordland.canonical.com (Postfix) with ESMTP id 0916DA185D6 for ; Wed, 8 Feb 2012 23:57:39 +0000 (UTC) Received: by iabz7 with SMTP id z7so2154994iab.11 for ; Wed, 08 Feb 2012 15:57:39 -0800 (PST) Received: by 10.50.94.228 with SMTP id df4mr12906460igb.12.1328745459396; Wed, 08 Feb 2012 15:57:39 -0800 (PST) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.231.12.131 with SMTP id x3cs23361ibx; Wed, 8 Feb 2012 15:57:38 -0800 (PST) Received: by 10.50.184.168 with SMTP id ev8mr37050800igc.29.1328745458323; Wed, 08 Feb 2012 15:57:38 -0800 (PST) Received: from mail-iy0-f178.google.com (mail-iy0-f178.google.com [209.85.210.178]) by mx.google.com with ESMTPS id x1si547627igm.16.2012.02.08.15.57.37 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 08 Feb 2012 15:57:38 -0800 (PST) Received-SPF: neutral (google.com: 209.85.210.178 is neither permitted nor denied by best guess record for domain of dmitry.antipov@linaro.org) client-ip=209.85.210.178; Authentication-Results: mx.google.com; spf=neutral (google.com: 209.85.210.178 is neither permitted nor denied by best guess record for domain of dmitry.antipov@linaro.org) smtp.mail=dmitry.antipov@linaro.org Received: by iage36 with SMTP id e36so1969908iag.37 for ; Wed, 08 Feb 2012 15:57:37 -0800 (PST) MIME-Version: 1.0 Received: by 10.50.77.137 with SMTP id s9mr9076077igw.0.1328745457584; Wed, 08 Feb 2012 15:57:37 -0800 (PST) Received: from localhost.localdomain.com ([108.60.121.129]) by mx.google.com with ESMTPS id al9sm1183115igc.5.2012.02.08.15.57.34 (version=SSLv3 cipher=OTHER); Wed, 08 Feb 2012 15:57:36 -0800 (PST) From: Dmitry Antipov To: Venki Pallipadi Cc: Russell King , Rusty Russell , Ingo Molnar , linux-kernel@vger.kernel.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linaro-dev@lists.linaro.org, patches@linaro.org, Dmitry Antipov Subject: [PATCH] sched: generalize CONFIG_IRQ_TIME_ACCOUNTING for X86 and ARM Date: Wed, 8 Feb 2012 15:58:36 -0800 Message-Id: <1328745516-14205-1-git-send-email-dmitry.antipov@linaro.org> X-Mailer: git-send-email 1.7.7.6 X-Gm-Message-State: ALoCoQkZiQppDljVXSNCTgnndJDN8XP+OvsOZ+WKOjWDdWMmOK3C5QfOmLNN/mg4TxwCI6zkf4S9 Generalize CONFIG_IRQ_TIME_ACCOUNTING between X86 and ARM, move "noirqtime=" option to common debugging code. For a bit of backward compatibility, X86-specific option "tsc=noirqtime" is preserved, but issues a warning. Suggested-by: Russell King Suggested-by: Venki Pallipadi Signed-off-by: Dmitry Antipov --- Documentation/kernel-parameters.txt | 9 +++++---- arch/arm/kernel/sched_clock.c | 3 +++ arch/x86/Kconfig | 11 ----------- arch/x86/kernel/tsc.c | 7 ++++--- include/linux/sched.h | 2 ++ lib/Kconfig.debug | 12 ++++++++++++ lib/Makefile | 2 ++ lib/irqtime.c | 12 ++++++++++++ 8 files changed, 40 insertions(+), 18 deletions(-) create mode 100644 lib/irqtime.c diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 033d4e6..b64a13f 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1719,6 +1719,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. noautogroup Disable scheduler automatic task group creation. + noirqtime [X86,ARM] Used to run time disable IRQ_TIME_ACCOUNTING, + should give a negligible performance improvement. + nobats [PPC] Do not use BATs for mapping kernel lowmem on "Classic" PPC cores. @@ -2636,10 +2639,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. as the stability checks done at bootup. Used to enable high-resolution timer mode on older hardware, and in virtualized environment. - [x86] noirqtime: Do not use TSC to do irq accounting. - Used to run time disable IRQ_TIME_ACCOUNTING on any - platforms where RDTSC is slow and this accounting - can add overhead. + [x86] noirqtime: obsoleted by "noirqtime" generic option, + see it's documentation for details. turbografx.map[2|3]= [HW,JOY] TurboGraFX parallel port interface diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c index 5416c7c..961bd2d 100644 --- a/arch/arm/kernel/sched_clock.c +++ b/arch/arm/kernel/sched_clock.c @@ -144,6 +144,9 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) */ cd.epoch_ns = 0; + if (!no_sched_irq_time) + enable_sched_clock_irqtime(); + pr_debug("Registered %pF as sched_clock source\n", read); } diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5bed94e..4759676 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -805,17 +805,6 @@ config SCHED_MC making when dealing with multi-core CPU chips at a cost of slightly increased overhead in some places. If unsure say N here. -config IRQ_TIME_ACCOUNTING - bool "Fine granularity task level IRQ time accounting" - default n - ---help--- - Select this option to enable fine granularity task irq time - accounting. This is done by reading a timestamp on each - transitions between softirq and hardirq state, so there can be a - small performance impact. - - If in doubt, say N here. - source "kernel/Kconfig.preempt" config X86_UP_APIC diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index a62c201..70510a3 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -103,14 +103,15 @@ int __init notsc_setup(char *str) __setup("notsc", notsc_setup); -static int no_sched_irq_time; - static int __init tsc_setup(char *str) { if (!strcmp(str, "reliable")) tsc_clocksource_reliable = 1; - if (!strncmp(str, "noirqtime", 9)) + if (!strncmp(str, "noirqtime", 9)) { + printk(KERN_WARNING "tsc: tsc=noirqtime is " + "obsolete, use noirqtime instead\n"); no_sched_irq_time = 1; + } return 1; } diff --git a/include/linux/sched.h b/include/linux/sched.h index 7d379a6..b3575b5 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1966,9 +1966,11 @@ extern void sched_clock_idle_wakeup_event(u64 delta_ns); * The reason for this explicit opt-in is not to have perf penalty with * slow sched_clocks. */ +extern int no_sched_irq_time; extern void enable_sched_clock_irqtime(void); extern void disable_sched_clock_irqtime(void); #else +#define no_sched_irq_time 1 static inline void enable_sched_clock_irqtime(void) {} static inline void disable_sched_clock_irqtime(void) {} #endif diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 8745ac7..236e814 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -299,6 +299,18 @@ config SCHEDSTATS application, you can say N to avoid the very slight overhead this adds. +config IRQ_TIME_ACCOUNTING + bool "Fine granularity task level IRQ time accounting" + depends on X86 || ARM + default n + ---help--- + Select this option to enable fine granularity task irq time + accounting. This is done by reading a timestamp on each + transitions between softirq and hardirq state, so there can be a + small performance impact. + + If in doubt, say N here. + config TIMER_STATS bool "Collect kernel timers statistics" depends on DEBUG_KERNEL && PROC_FS diff --git a/lib/Makefile b/lib/Makefile index 18515f0..44d67d4 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -49,6 +49,8 @@ obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o obj-$(CONFIG_DEBUG_LIST) += list_debug.o obj-$(CONFIG_DEBUG_OBJECTS) += debugobjects.o +obj-$(CONFIG_IRQ_TIME_ACCOUNTING) += irqtime.o + ifneq ($(CONFIG_HAVE_DEC_LOCK),y) lib-y += dec_and_lock.o endif diff --git a/lib/irqtime.c b/lib/irqtime.c new file mode 100644 index 0000000..10d440d --- /dev/null +++ b/lib/irqtime.c @@ -0,0 +1,12 @@ +#include +#include + +int no_sched_irq_time; + +static int __init irqtime_setup(char *str) +{ + no_sched_irq_time = 1; + return 1; +} + +__setup("noirqtime", irqtime_setup);