Re: Intel P6 vs P7 system call performance

[H. Peter Anvin]

Jeremy Fitzhardinge wrote:
> On Tue, 2002-12-17 at 09:55, Linus Torvalds wrote:
> 
>>Uli, how about I just add one ne warchitecture-specific ELF AT flag, which
>>is the "base of sysinfo page". Right now that page is all zeroes except
>>for the system call trampoline at the beginning, but we might want to add
>>other system information to the page in the future (it is readable, after
>>all).
> 
> 
> The P4 optimisation guide promises horrible things if you write within
> 2k of a cached instruction from another CPU (it dumps the whole trace
> cache, it seems), so you'd need to be careful about mixing mutable data
> and the syscall code in that page.
> 
> Immutable data should be fine.
>         

Yes, you really want to use a second page.

	-hpa