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From: "Sarin, Suseelan" <suseelan@gmail.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-rt-users@vger.kernel.org
Subject: Re: Calculating latency using high resolution timer
Date: Thu, 10 Jun 2010 11:43:54 +0530	[thread overview]
Message-ID: <AANLkTikQ5Arhc-msaILLa1oFPbTHbg7yXxSKp3F-T7cM@mail.gmail.com> (raw)
In-Reply-To: <alpine.LFD.2.00.1006092028280.2933@localhost.localdomain>

>> this. My doubt is, if the system is loaded to the extend that an RT
>> task can have considerable latency, can I trust the time read from the
>> high resolution timer of the system?
>
> Yes, it's accurate. cyclictest relies on that as well.
>
>> Also, with these measurements, I am seeing a ~5msec latency. Is there
>> a way I can exactly point out the reason for this latency?
>
> Tracing. See cyclictest.c for how that's done.

Thank you. I will check the cyclic test code and get back.

  reply	other threads:[~2010-06-10  6:13 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <AANLkTikuWI08hHb2BdzicdEYKO4SdQlCL17gDQgqwrKz@mail.gmail.com>
2010-06-09 16:21 ` Calculating latency using high resolution timer Sarin, Suseelan
2010-06-09 18:30   ` Thomas Gleixner
2010-06-10  6:13     ` Sarin, Suseelan [this message]
     [not found]   ` <4C0FD3E4.9090304@gmail.com>
2010-06-10  6:11     ` Sarin, Suseelan

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