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From: john stultz <johnstul@us.ibm.com>
To: Linus Torvalds <torvalds@transmeta.com>, andrea <andrea@suse.de>
Cc: Michael Hohnbaum <hbaum@us.ibm.com>,
	"Martin J. Bligh" <mbligh@aracnet.com>,
	george anzinger <george@mvista.com>,
	lkml <linux-kernel@vger.kernel.org>,
	ak@muc.de
Subject: [RFC] vsyscall_A0 LD_PRELOAD implementation
Date: 18 Oct 2002 11:54:01 -0700	[thread overview]
Message-ID: <1034967241.4048.9.camel@cog> (raw)
In-Reply-To: <1034915132.1681.144.camel@cog>

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Here's an example use of the vsyscall via LD_PRELOAD.

Attached is an example library that can be LD_PRELOADED to alias glib's
gettimeofday function w/ the vsyscall implementation. I've also included
a quick performance test to give a rough idea of the savings this gives.

Example run on a SMP P4 box:

[jstultz@elm3b52 vsyscall_test]$ ./run.sh 
Normal gettimeofday
gettimeofday ( 1391621us / 1000000runs ) = 1.391620us
vsyscall LD_PRELOAD gettimeofday
gettimeofday ( 286567us / 1000000runs ) = 0.286567us

So it looks like a pretty big win.

thanks
-john


[-- Attachment #2: vsyscall_test.tar.gz --]
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  parent reply	other threads:[~2002-10-18 18:58 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-10-18  4:25 [RFC][PATCH] linux-2.5.34_vsyscall_A0 john stultz
2002-10-18  4:26 ` [RFC] linux-2.5.34_vsyscall_A0 - Test App john stultz
2002-10-18 11:14 ` [RFC][PATCH] linux-2.5.34_vsyscall_A0 Andrea Arcangeli
2002-10-18 16:13   ` Stephen Hemminger
2002-10-18 16:45     ` george anzinger
2002-10-18 17:11       ` Andrea Arcangeli
2002-10-18 17:19         ` Linus Torvalds
2002-10-18 17:21           ` Andrea Arcangeli
2002-10-18 18:37             ` Stephen Hemminger
2002-10-18 18:51               ` Andrea Arcangeli
2002-10-18 19:30           ` george anzinger
2002-10-18 17:01     ` Andrea Arcangeli
2002-10-21 13:18     ` Alan Cox
2002-10-21 17:15       ` john stultz
2002-10-18 16:39   ` john stultz
2002-10-18 18:54 ` john stultz [this message]
2002-10-21 22:44 ` Stephen Hemminger

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