Messages in this thread | | | Date | Tue, 07 Oct 2008 16:25:00 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] [1/3] Provide rdtscll() asm/msr.h for user space |
| |
Andi Kleen wrote: > >> I would suggest writing a <sys/tsc.h> header file and submitting to the >> glibc people, instead, or perhaps even better, start a libarch/libx86 tree. > > That wouldn't work on old kernels. asm/msr.h has been the traditional > interface for this and rdtsc has worked forever (at least dating back to 2.0) > rdtscll is a bit newer, but still in Linux terms ancient (2.4) >
It would definitely work on older kernels. Just don't stomp on the kernel's namespace and you can do whatever you want.
> Also in my experience distributions are extremly slow at keeping up > with glibc, so even if this was added to glibc it would be probably > years before it would be actually usable :/ And I see about zero > point in changing a perfectly fine include name breaking everything old.
So ship the include file with your utility. Hardly a big deal. But yes, that's part of why I'm mentioning the idea of putting it in a separate library, which can also house other low-level constructs.
> Anyways if you insist I can probably deal without > but I (and likely others) would think something nasty about you every time > I have to cut'n'paste that code again. Do you really want to risk that? @)
If you're really incapable of maintaining a single user-mode header file with a handful of one-liners in a sane way, then definitely.
-hpa
| |