DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=subject:from:reply-to:to:cc:in-reply-to:references:content-type
         :organization:date:message-id:mime-version:x-mailer
         :content-transfer-encoding;
        b=nfmmCN+rvTz8k7hcViGb7982+jNVFQDgf4PLV092goezUgj34VVwLYaeIwoWCwD0B5
         mWY6wZXUHHzs4TYDmxIDtdJDN36K9OaNY5A+zmVZ0z0a2W8gbG0BixRjU5pgPUQ3GsHT
         GlCTX5ADREt++23egusOX0fFTtZA9U2bU625s=
Subject: Re: [PATCH -v4 3/9] tracing: add MIPS specific trace_clock_local()
From: Wu Zhangjin <wuzhangjin@gmail.com>
Reply-To: wuzhangjin@gmail.com
To: rostedt@goodmis.org
Cc: linux-kernel@vger.kernel.org, linux-mips@linux-mips.org,
       Thomas Gleixner <tglx@linutronix.de>,
       Ralf Baechle <ralf@linux-mips.org>,
       Nicholas Mc Guire <der.herr@hofr.at>
In-Reply-To: <1256136393.18347.2997.camel@gandalf.stny.rr.com>
References: <028867b99ec532b84963a35e7d552becc783cafc.1256135456.git.wuzhangjin@gmail.com>
	 <2f73eae542c47ac5bbb9f7280e6c0271d193e90d.1256135456.git.wuzhangjin@gmail.com>
	 <3f0d3515f74a58f4cfd11e61b62a129fdc21e3a7.1256135456.git.wuzhangjin@gmail.com>
	 <1256136393.18347.2997.camel@gandalf.stny.rr.com>
Content-Type: text/plain
Organization: DSLab, Lanzhou University, China
Date: Wed, 21 Oct 2009 23:11:07 +0800
Message-Id: <1256137867.11274.8.camel@falcon>
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 2971
Lines: 87

On Wed, 2009-10-21 at 10:46 -0400, Steven Rostedt wrote:
> On Wed, 2009-10-21 at 22:34 +0800, Wu Zhangjin wrote:
> > This patch add the mips_timecounter_read() based high precision version
> > of trace_clock_local().
> > 
> > Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
> > ---
> >  arch/mips/kernel/Makefile      |    6 ++++++
> >  arch/mips/kernel/trace_clock.c |   37 +++++++++++++++++++++++++++++++++++++
> >  2 files changed, 43 insertions(+), 0 deletions(-)
> >  create mode 100644 arch/mips/kernel/trace_clock.c
> > 
> > diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
> > index 8e26e9c..f228868 100644
> > --- a/arch/mips/kernel/Makefile
> > +++ b/arch/mips/kernel/Makefile
> > @@ -8,6 +8,10 @@ obj-y		+= cpu-probe.o branch.o entry.o genex.o irq.o process.o \
> >  		   ptrace.o reset.o setup.o signal.o syscall.o \
> >  		   time.o topology.o traps.o unaligned.o watch.o
> >  
> > +ifdef CONFIG_FUNCTION_TRACER
> > +CFLAGS_REMOVE_trace_clock.o = -pg
> > +endif
> > +
> >  obj-$(CONFIG_CEVT_BCM1480)	+= cevt-bcm1480.o
> >  obj-$(CONFIG_CEVT_R4K_LIB)	+= cevt-r4k.o
> >  obj-$(CONFIG_MIPS_MT_SMTC)	+= cevt-smtc.o
> > @@ -24,6 +28,8 @@ obj-$(CONFIG_SYNC_R4K)		+= sync-r4k.o
> >  obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
> >  obj-$(CONFIG_MODULES)		+= mips_ksyms.o module.o
> >  
> > +obj-$(CONFIG_FTRACE)		+= trace_clock.o
> > +
> >  obj-$(CONFIG_CPU_LOONGSON2)	+= r4k_fpu.o r4k_switch.o
> >  obj-$(CONFIG_CPU_MIPS32)	+= r4k_fpu.o r4k_switch.o
> >  obj-$(CONFIG_CPU_MIPS64)	+= r4k_fpu.o r4k_switch.o
> > diff --git a/arch/mips/kernel/trace_clock.c b/arch/mips/kernel/trace_clock.c
> > new file mode 100644
> > index 0000000..2e3475f
> > --- /dev/null
> > +++ b/arch/mips/kernel/trace_clock.c
> > @@ -0,0 +1,37 @@
> > +/*
> > + * This file is subject to the terms and conditions of the GNU General Public
> > + * License.  See the file "COPYING" in the main directory of this archive for
> > + * more details.
> > + *
> > + * Copyright (C) 2009 Lemote Inc. & DSLab, Lanzhou University, China
> > + * Author: Wu Zhangjin <wuzj@lemote.com>
> > + */
> > +
> > +#include <linux/clocksource.h>
> > +#include <linux/sched.h>
> > +
> > +#include <asm/time.h>
> > +
> > +/*
> > + * trace_clock_local(): the simplest and least coherent tracing clock.
> > + *
> > + * Useful for tracing that does not cross to other CPUs nor
> > + * does it go through idle events.
> > + */
> > +u64 trace_clock_local(void)
> > +{
> > +	unsigned long flags;
> > +	u64 clock;
> > +
> > +	raw_local_irq_save(flags);
> > +
> > +	preempt_disable_notrace();
> 
> Why have the preempt_disable? You disable interrupts already, that will
> prevent any preemption at that point.
> 

just removed it.

Thanks!

Regards,
	Wu Zhangjin

--
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/