From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <1b61f389440311188b1c018fae979214@quintile.net>
From: "Steve Simon" <steve@quintile.net>
Date: Sat, 19 Feb 2011 10:34:19 +0000
To: 9fans@9fans.net
In-Reply-To: <AANLkTimtZmBhu8cW_QrUuA6dQ491xdYKVQMb6WcB9bxB@mail.gmail.com>
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Subject: Re: [9fans] Modern development language for Plan 9,
	WAS: Re: RESOLVED: recoving important header file rudely
Topicbox-Message-UUID: b1a07694-ead6-11e9-9d60-3106f5b1d025

> Benchmark utilities to measure the overhead of syscalls. It's cheating
> to do for getpid, but for other things like gettimeofday, it's
> *extremely* nice. Linux's gettimeofday(2) beats the socks off of the
> rest of the time implementations. About the only faster thing is to
> get CPU speed and use rdtsc. Certainly no other OS allows you to get
> the timestamp faster with a syscall.

Here is where my memory gets hazy, however Solaris 2 had a very fast
implementation of gettimeofday(), it was still a syscall I think but
had a shortcut in the kernel.

This was added (If I rembember correctly) to get a database (Sybase
I think) to run on Solaris 2 as fast as it always used to run on SunOS.
This was commented in the code as a special, ugly hack as a result of
extreme pressure from an important customer.

I wonder if Linux inherited the hack from Solaris?

-Steve