From: Matthew Hall <mhall-Hv3ogNYU3JfZZajBQzqCxQ@public.gmane.org>
To: Ravi Kumar Iyer <Ravi.Iyer-pccXkzZloW5BDgjK7y7TUQ@public.gmane.org>
Cc: "dev-VfR2kkLFssw@public.gmane.org" <dev-VfR2kkLFssw@public.gmane.org>
Subject: Re: cost of reading tsc register
Date: Mon, 20 Apr 2015 09:21:41 -0700 [thread overview]
Message-ID: <20150420162141.GB20826@mhcomputing.net> (raw)
In-Reply-To: <115e8a38d223487488d22a99f53cc926-AcH5Oudqfb/hfjeZMvbk8syo0RDPibkP@public.gmane.org>
On Mon, Apr 20, 2015 at 02:37:53PM +0000, Ravi Kumar Iyer wrote:
> We were doing some code optimizations , running DPDK based applications, and chanced upon the rte_rdtsc function [ to read tsc timestamp register value ] consuming cpu cycles of the order of 100clock cycles with a delta of upto 40cycles at times [ 60-140 cycles]
>
> We are actually building up a cpu intensive application which is also very clock cycle sensitive and this is impacting our implementation.
>
> To validate the same using a small/vanilla application we wrote a small code and tested on a single core.
> Has anyone else faced a similar issue or are we doing something really atrocious here.
What happened when you tried rte_rdtsc_precise ?
Matthew.
next prev parent reply other threads:[~2015-04-20 16:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-20 14:37 cost of reading tsc register Ravi Kumar Iyer
[not found] ` <115e8a38d223487488d22a99f53cc926-AcH5Oudqfb/hfjeZMvbk8syo0RDPibkP@public.gmane.org>
2015-04-20 15:37 ` Stephen Hemminger
2015-04-20 16:21 ` Matthew Hall [this message]
2015-04-22 7:53 ` Pawel Wodkowski
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