Re: [PATCH] RTC: Add mmap method to rtc character driver

H. Peter Anvin
2006-07-25T19:11:01Z

Neil Horman wrote:
>
> In general I agree, but that only works if you operate on a platform that
> supports virtual syscalls, and has vdso configured. I'm not overly familiar
> with vdso, but I didn't think vdso could be supported on all platforms/arches.
> This seems like it might be a nice addition in those cases.
>

Not really. This introduces a potentially very difficult support
user-visible interface. Consider a tickless kernel -- you might end up
taking tick interrupts ONLY to update this page, since you don't have
any way of knowing when userspace wants to look at it.

-hpa