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From: Andi Kleen <andi@firstfloor.org>
To: john stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@tglx.de>,
	lkml <linux-kernel@vger.kernel.org>
Subject: Re: Duplicate vsyscall/vdso gettimeofday implementations on x86_64
Date: Sat, 18 Jul 2009 08:07:44 +0200	[thread overview]
Message-ID: <87ab32wmkv.fsf@basil.nowhere.org> (raw)
In-Reply-To: <1247871284.8334.42.camel@localhost.localdomain> (john stultz's message of "Fri, 17 Jul 2009 15:54:44 -0700")

john stultz <johnstul@us.ibm.com> writes:
>
> Hrmm. Can we deprecate the old method and push glibc to use the new one?

That would break every old 64bit executable. Also not there are programs
who don't use glibc.

Also glibc's way of calling the vDSO is still somewhat inefficient
(although that could be probably fixed)

> If we remove it the vsyscall interface will old glibc's fall-back
> gracefully? 

They would crash gracefully.

I had a couple of different transition plans, but they were all fairly
complicated and had various disadvantages, so in the end nothing got
done and the old code just left in.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.

  reply	other threads:[~2009-07-18  6:07 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-07-17 22:02 Duplicate vsyscall/vdso gettimeofday implementations on x86_64 john stultz
2009-07-17 22:12 ` Andi Kleen
2009-07-17 22:54   ` john stultz
2009-07-18  6:07     ` Andi Kleen [this message]
2009-07-18  6:50       ` Andi Kleen
2009-07-18 22:03       ` john stultz
2009-07-19  7:22         ` Andi Kleen

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