From: Andi Kleen <ak@muc.de>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>,
dmitry.torokhov@gmail.com
Subject: Re: [PATCH] Turn rdmsr, rdtsc into inline functions, clarify names
Date: 6 Aug 2006 05:16:43 +0200
Date: Sun, 6 Aug 2006 05:16:43 +0200 [thread overview]
Message-ID: <20060806031643.GA43490@muc.de> (raw)
In-Reply-To: <1154832963.29151.21.camel@localhost.localdomain>
> Please reconsider. This isn't about being pretty, it's about not
> having hidden side-effects,
I wouldn't call it hidden, it's well defined in the architecture.
> and having typechecking.
The existing code will already reject any non integer and I don't
see a particular need to be more strict than that.
> > If you feel a need to clean up I would suggest you convert more
> > users over to the ll variants which take a single 64bit value
> > instead of two 32bit ones.
>
> You mean the l and ll variants? The 64 bit variants are rdmsrl and
> rdtscll, not to be confused with rdtscl, which returns the lower 32
> bits. This confusion caused the x86_64 bug in gameport.c
Why does gameport access MSRs or TSCs? That sounds like a bug in itself.
<looking at the code>
This whole thing is broken, e.g. on a preemptive kernel when the
code can switch CPUs
Dmitry, I would suggest to convert it over to do_gettimeofday and remove
all the architecture ifdefs.
Or maybe just remove it completely. Who cares about the speed of a gameport
anyways? And why can't they measure it in user space?
> See why I want to fix these names?
No.
> So if you would prefer u64 rdtsc64(), u32 rdtsc_low(), u64 rdmsr64(int
> msr), u32 rdmsr_low(int msr), I can convert everyone to that, although
> it's a more invasive change...
I think things are most fine right now, except that I think most users
of high low should be converted to work directly on 64bit quantities.
-Andi
next prev parent reply other threads:[~2006-08-06 3:16 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1154771262.28257.38.camel@localhost.localdomain>
2006-08-06 2:38 ` [PATCH] Turn rdmsr, rdtsc into inline functions, clarify names Andi Kleen
2006-08-06 2:56 ` Rusty Russell
2006-08-06 2:58 ` H. Peter Anvin
2006-08-06 3:09 ` Rusty Russell
2006-08-06 3:11 ` H. Peter Anvin
2006-08-06 3:49 ` Rusty Russell
2006-08-06 3:16 ` Andi Kleen [this message]
2006-08-06 3:52 ` Rusty Russell
2006-08-06 14:58 ` Andi Kleen
2006-08-07 2:43 ` Dmitry Torokhov
2006-08-07 8:48 ` Andi Kleen
2006-08-07 11:09 ` Vojtech Pavlik
2006-08-07 12:28 ` Andi Kleen
2006-08-07 12:48 ` Vojtech Pavlik
2006-08-07 12:56 ` Andi Kleen
2006-08-07 13:18 ` Vojtech Pavlik
2006-08-07 13:32 ` Dmitry Torokhov
2006-08-07 15:01 ` Andi Kleen
2006-08-07 15:19 ` Andreas Mohr
2006-08-07 15:57 ` Andi Kleen
2006-08-07 16:04 ` Vojtech Pavlik
2006-08-07 16:12 ` Andi Kleen
2006-08-07 19:22 ` Vojtech Pavlik
2006-08-14 20:13 ` Pavel Machek
2006-08-07 11:07 ` Vojtech Pavlik
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