Thread (2 messages) flat view 2 messages, 2 authors, 2002-05-09

Re: Bogomips and loops_per_jiffy

From: Troy Benjegerdes <hidden>
Date: 2002-05-09 15:08:46

quoted
quoted
while ((next_dec = tb_ticks_per_jiffy - tb_delta(&jiffy_stamp)) < 0)
{

Now that next_dec is unsigned, this condition is always false.
Yes I wrote this in the most possible compact way.  But I don't understand
(yet) how this can cause problems. You have a security margin of about 2
billion timbase ticks.
The problem occurs when calibrating the delay loop, and the timebase is
very large.

http://lists.linuxppc.org/linuxppc-embedded/200205/msg00040.html

We could probably just avoid all this and do 'set_tb(0,0)' in time_init
(since we go and try to sync the timebase on SMP systems anyway)
quoted
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Here is another patch I suggest to replace yours.
Its in attachement to this email.
I tested it, and it seems OK.

I did not include your modification made to the type of local variables in
function do_settimeofday().
I do not see how it is related to our problem.
That one is better for symmetry between gettimeofday and settimeofay,
but OTOH the types in the timeval structures are defined as signed.
(Wrongly IMHO)

Could you please decribe exactly the problem or forward me the messages.
(Which machine, processor and compiler just in case). It seems that I have
been automagically dropped from linuxppc-embedded, unfortunately!

	Regards,
	Gabriel.

P.S: please try to get patches attached as text. It appears as
Application/BINARY which is quite annoying.


--
Troy Benjegerdes | master of mispeeling | 'da hozer' |  hozer@drgw.net
-----"If this message isn't misspelled, I didn't write it" -- Me -----
"Why do musicians compose symphonies and poets write poems? They do it
because life wouldn't have any meaning for them if they didn't. That's
why I draw cartoons. It's my life." -- Charles Schulz

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
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