Messages in this thread | | | Subject | Re: [ANNOUNCE] ktimers subsystem | From | Thomas Gleixner <> | Date | Tue, 20 Sep 2005 01:12:22 +0200 |
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On Mon, 2005-09-19 at 16:04 -0700, Christoph Lameter wrote: > On Tue, 20 Sep 2005, Thomas Gleixner wrote: > > > Hmm. I don't understand the argument line completely. > > > > 1. The kernel has to provide ugly mechanisms because a lot of > > applications implementations are doing the Wrong Thing ? > > Lets skip the "wrong thing"... Or are you saying that glibc and all the > apps are all wrong? > > Applications call gettimeofday for a variety of reasons. One is because it > is widely available over different platformsn and application want to > schedule things, need timestamps etc etc.
Accepted. But I still doubt that the number of calls to gettimeofday is in anyway justified. The question I'm asking if it is really worth a long and epic discussion about a single add instruction ?
> > > Many platforms can execute gettimeofday > > > without having to enter the kernel. > > > > Which ones ? How is this achieved with respect to all the time adjust, > > correction... code ? > > IA64 f.e. has a special instruction that allows access to kernel user > space without having to do a context switch.
Ok, was not aware of that and John kindly clarified this already.
tglx
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