From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan Larmour To: Xavier Wang Cc: ecos-discuss@sources.redhat.com Subject: Re: [ECOS] nested interrupts Date: Thu, 18 Jan 2001 22:37:00 -0000 Message-id: <3A67E092.F01CBE44@redhat.com> References: <003b01c0811f$196395e0$6f2314ac@realtek.com.tw> <3A671913.9090209@caracal-tech.com> <00e201c081d2$c303df20$6f2314ac@realtek.com.tw> X-SW-Source: 2001-01/msg00333.html Xavier Wang wrote: > But as I knew, ISRs should be as short as > possible to reduce the time of masking interrupts and other non-critical > stuff can be processed in DSRs. So I don't understand what the following > means: > > "Bearing this in mind, the only thing DSR absolutely has to do is to > notify the scheduler. All the rest ought to be done either in an ISR or > in a thread." The DSR should just wake or signal a thread to let it know that the interrupt happened, that's all. You can't do that from an ISR. All other processing should take place in a thread - both ISRs and DSRs should be short and simple like that, otherwise you will lose determinism. Jifl -- Red Hat, Rustat House, Clifton Road, Cambridge, UK. Tel: +44 (1223) 271062 Un cheval, pas du glue. Pas du cheval, beaucoup du glue. || Opinions==mine