I found a problem with the last version.  The attached is for 
2.5.65-1.1171 (i.e. after the other post 2.5.65 changes).  The bug is 
fixed, and the code even simpler here.

The problem in the prior patch was that cascade should return:
(index +1) &... not  index &...

Here I changed the call to cascade() to expect "index" back so it 
checks for 0 instead of 1.  Nice and simple.

-g

Tim Schmielau wrote:
> On Wed, 19 Mar 2003, george anzinger wrote:
> 
> 
>>In this case, the simple fix is to bump the
>>base->timer_jiffies at the beginning of the loop rather than the end.
>>   This would cause the new timer to be put in the next jiffie instead
>>of the current one AND it is free!
> 
> 
> Yes, doing it this way looks correct to me.
> 
> 
>>>No, with the current implementation we need
>>> #define INDEX(N) (base->timer_jiffies >> (TVR_BITS + N * TVN_BITS) +1) &
>>> TVN_MASK
>>>although I'd like to see that cleaned up.
>>
>>I tried with the +1 and boot hangs trying to set up networking.  I
>>think the difference is that the init code is trying to set things up
>>the way they would look AFTER cascade executes and this is doing it
>>BEFORE the cascade call.
> 
> 
> With the above change, it should be correct without the +1
> 
> 
>>>Why 'jiffies -1'? This will just be made up for in the first
>>>timer interrupt, where timer_jiffies will get incremented twice.
>>
>>Again, I removed the -1 in the attached.
> 
> 
> If you really want to be conservative, we'd better start with
> INITIAL_JIFFIES. Should be the same anyways. But if not, we might lose a
> timer scheduled for INITIAL_JIFFIES (not that I think it's possible to
> insert one before timer initialisation in the first place :-)
> or even a timer cascade.
> 
> 
>>>Did you bother to test the patch? It doesn't even boot for me, and I don't
>>>see how it is supposed to.
>>>I'll look into it more closely in the evening. Have to go to work now.
>>
>>The old one ran on 2.5.64 but not 2.5.65 ???  I found and fixed a bug
>>(index needs to be caculated INSIDE the while loop) that seems to have
>>been the cause.
> 
> 
> Ok will test in the evening.
> 
> Tim
> 
> 

-- 
George Anzinger   george@mvista.com
High-res-timers:  http://sourceforge.net/projects/high-res-timers/
Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml