Re: [linux-audio-dev] low-latency scheduling patch for 2.4.0

[David Woodhouse <dwmw2@infradead.org>]

jadb@redhat.com said:
> (If you're running a program XIP from flash and a  RT interrupt leaves
> the flash in a unreadable state, boom!).

Bad example. I don't expect Linux to support writable XIP any time in the 
near future. The only thing I envisage myself doing to help people who want 
writable XIP is to take away their crackpipe.

Until we get dual-port flash, of course.

The thing that really does concern me about the flash driver code is the
fact that it often wants to wait for about 100µs. On machines with
HZ==100, that sucks if you use udelay() and it sucks if you schedule(). So
we end up dropping the spinlock (so at least bottom halves can run again)
and calling:

static inline void cfi_udelay(int us)
{
        if (current->need_resched)
                schedule();
        else
                udelay(us);
}


--
dwmw2


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