From: "H. Peter Anvin" <hpa@zytor.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: Erik Bosman <ejbosman@cs.vu.nl>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
Arjan van de Ven <arjan@infradead.org>,
Andrea Arcangeli <andrea@cpushare.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] Add prctl commands PR_GET_TSC and PR_SET_TSC
Date: Sun, 13 Apr 2008 13:53:17 -0700 [thread overview]
Message-ID: <480272BD.9010404@zytor.com> (raw)
In-Reply-To: <48027225.6000609@firstfloor.org>
Andi Kleen wrote:
>> I think what Erik is trying to do is to make it possible to disable as
>> many of these in the kernel as possible; I/O is easy, it's off by
>> default; RDTSC and RDPMC can be disabled in the kernel, and I think
>> even XSTORE can be disabled.
>
> I'm a little sceptical it will work reliably, but we'll see.
>
> There's also LSL (forgot that earlier). It is used by the vgetcpu()
> because it's faster than CPUID or RDTSCP. Kernel
> sets a magic segment up which has different limits for different CPUs.
>
Yeah, that's unlikely to be found in code that isn't actively looking
for it, though.
-hpa
prev parent reply other threads:[~2008-04-13 20:57 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-11 16:54 [PATCH 1/3] Add prctl commands PR_GET_TSC and PR_SET_TSC Erik Bosman
2008-04-13 9:07 ` Andi Kleen
2008-04-13 9:44 ` Erik Bosman
2008-04-13 16:47 ` Andi Kleen
2008-04-13 19:29 ` H. Peter Anvin
2008-04-13 20:50 ` Andi Kleen
2008-04-13 20:53 ` H. Peter Anvin [this message]
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