From: "H. Peter Anvin" <hpa@zytor.com>
To: Andi Kleen <ak@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>,
Mike Frysinger <vapier@gentoo.org>,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [patch] use __asm__ and __volatile__ in asm-x86_64/msr.h
Date: Wed, 20 Jun 2007 08:46:42 -0700 [thread overview]
Message-ID: <46794BE2.5020108@zytor.com> (raw)
In-Reply-To: <200706182053.04116.ak@suse.de>
Andi Kleen wrote:
>> asm-i386/msr.h should not be exported to userspace at all, it contains
>> nothing but kernel-internal helpers.
>
> Actually rdtsc and rdtscll and potentially rdpmc which is in there can be very
> useful in user space if you know what you're doing. Unfortunately a lot of its users don't,
> but not having the include probably won't stop them either.
More likely, people will just re-implement them incorrectly.
However, the rdtsc() definition in the kernel is weird (and removable, I
think there are no more users -- I have it removed in my MSR driver
rewrite tree which I need to get off my arse and push.) Most users
would expect the rdtscll() functionality with the rdtsc() name.
-hpa
next prev parent reply other threads:[~2007-06-20 15:54 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-18 6:09 [patch] use __asm__ and __volatile__ in asm-x86_64/msr.h Mike Frysinger
2007-06-18 7:35 ` H. Peter Anvin
2007-06-18 14:02 ` Mike Frysinger
2007-06-18 18:36 ` Christoph Hellwig
2007-06-18 18:53 ` Andi Kleen
2007-06-20 15:46 ` H. Peter Anvin [this message]
2007-07-23 0:45 ` Mike Frysinger
2007-07-23 1:18 ` H. Peter Anvin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=46794BE2.5020108@zytor.com \
--to=hpa@zytor.com \
--cc=ak@suse.de \
--cc=akpm@linux-foundation.org \
--cc=hch@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=vapier@gentoo.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.