Messages in this thread | | | From | Mark Salisbury <> | Subject | Re: No 100 HZ timer ! | Date | Mon, 9 Apr 2001 14:19:28 -0400 |
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this is one of linux biggest weaknesses. the fixed interval timer is a throwback. it should be replaced with a variable interval timer with interrupts on demand for any system with a cpu sane/modern enough to have an on-chip interrupting decrementer. (i.e just about any modern chip)
On Mon, 09 Apr 2001, Jeff Dike wrote: > schwidefsky@de.ibm.com said: > > I have a suggestion that might seem unusual at first but it is > > important for Linux on S/390. We are facing the problem that we want > > to start many (> 1000) Linux images on a big S/390 machine. Every > > image has its own 100 HZ timer on every processor the images uses > > (normally 1). On a single image system the processor use of the 100 HZ > > timer is not a big deal but with > 1000 images you need a lot of > > processing power just to execute the 100 HZ timers. You quickly end up > > with 100% CPU only for the timer interrupts of otherwise idle images. > > This is going to be a problem for UML as well, and I was considering something > very similar. I did a quick scan of your prose, and the description sounds > like what I had in mind. > > So, count me in as a supporter of this. > > A small request: Since S/390 is not the only port that needs this, I'd be > happy if it was made as generic as possible (and it may already be, I haven't > gone through the code yet). > > Jeff > > > - > 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/ -- /*------------------------------------------------** ** Mark Salisbury | Mercury Computer Systems ** ** mbs@mc.com | System OS - Kernel Team ** **------------------------------------------------** ** I will be riding in the Multiple Sclerosis ** ** Great Mass Getaway, a 150 mile bike ride from ** ** Boston to Provincetown. Last year I raised ** ** over $1200. This year I would like to beat ** ** that. If you would like to contribute, ** ** please contact me. ** **------------------------------------------------*/
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