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Date: Mon, 26 Nov 2012 12:39:32 +0100
From: Lukasz Wojcik <lukasz.wojcik@zoho.com>
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To: Luigi Rizzo <rizzo@iet.unipi.it>
Subject: Re: syscall cost freebsd vs linux ?
References: <20121119193202.GA79496@onelab2.iet.unipi.it>
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On 11/19/12 20:32, Luigi Rizzo wrote:
> today i was comparing the performance of some netmap-related code
> on FreeBSD and Linux (RELENG_9 vs 3.2) and i was surprised to see that
> our system calls are significantly slower.
> On comparable hardware (i7-2600k vs E5-1650) the syscall
> getppid() takes about 95ns on FreeBSD and 38ns on linux.
>
> (i make sure not to use gettimeofday(), which in linux is through vdso,
> and getpid(), which is cached by glibc).
>
> Any idea on why there is this difference and whether/how
> we can reduce it ?
>

I'm curious about how did you measure that ? Could you write some more 
about your methodology ?

-LW

> cheers
> luigi
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