Messages in this thread | | | Subject | Re: sleep and wakeup at microsecond boundary | From | "NucleoDyne Systems, " "Inc." <> | Date | 06 Sep 2004 22:46:50 -0700 |
| |
Hello, Let me explain the requirement a little more in detail.
Consider the routine sleep_on_timeout(, timeout) in sched.c:
A timer is started and then schedule() is called. The timer expires after present jiffies + timeout (in jiffies) period.
On x86 the jiffies is updated every time PIT raises interrupt and do_timer() is called, i.e. once in every 10ms.
So we can set timeout in multiples of 10ms.
We are developing a very powerful system (not x86 based) with multiple CPUs, one of them will be running linux and will act as a co-processor for the other CPUs running different OS.
On the CPU running linux we need to be able to call sleep_on_timeout() with more granular expiration time, may be in multiples of microseconds.
I already have done the investigation and looking for feedback from the developers on all possible issues.
Hope this explains.
Thanks, Kallol Biswas
On Sun, 2004-09-05 at 00:09, Mike Galbraith wrote: > At 12:51 PM 9/4/2004 -0700, NucleoDyne Systems, " "Inc. wrote: > >Hello, > > We have a requirement to implement the sleep and wakeup mechanism > >at microsecond boundary in 2.4 kernel. > > I've re-visited this message about 10 times now, so I suppose I'm curious > enough to ask: why on God's green Earth would someone want to do > that? (to _any_ kernel, but I'm mostly wondering why [TILT] anyone would > do such a thing to a GP kernel) > > -Mike
On Sat, 2004-09-04 at 12:51, NucleoDyne Systems, Inc. wrote: \
> Hello, > We have a requirement to implement the sleep and wakeup mechanism > at microsecond boundary in 2.4 kernel. The intent of this mail is to > start a discussion on this topic and collect inputs from the kernel > developers. Any reply on the issues of implementing such a feature will > be greatly appreciated. > > Thanks, > Kallol Biswas
-- -- NucleoDyne Corporation nucleon@nucleodyne.com www.nucleodyne.com --
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |