On Tue, 13 Oct 1998, Glynn Clements wrote:
>I didn't say that it mustn't be done; I said that bad things *may*
^^^
Hmm yes it' was an English problem, excuse me...
>I had no idea whether changing it by a factor of 10 (to 1000) on x86
>would.
I read of some people that done that fine. Probably you should than
recompile procps but this is a minor issue.
>> What is "flip buffers overflowing". Could you point me out the code are
>> you referring?
>
>Not to any specific code, but I recall a discussion on the linux-net
>list about the serial driver using flip buffers (the IRQ handler
>writes to one buffer, read()s are satisfied from the other, the
>buffers are flipped on a timer running at HZ. Or at least that's my
>recollection; I could be totally wrong). If this is the case, then
>making HZ too low could cause the buffer to overrun.
Yes probably it could happens but the serial driver if well written should
have a way to catch the overrun (should be the equivalent of the tbusy
flag in the network drivers if I remeber well). I don' t think it' s safe
to not check for overruns only doing the calc of the serial interrupt
frequency and the timer interrupt frequency. That would be not a robust
implementation I think. In general HZ is an arch #define to be changed
without major problems in the common kernel code.
Andrea Arcangeli
