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SubjectRe: typo in scsi_obsolete.c


On Sun, 29 Nov 1998, Andrea Arcangeli wrote:

> On Sun, 29 Nov 1998, Gerard Roudier wrote:
>
> >> + /* FIXME: last_reset == 0 is allowed */
>
> This mean last_reset == 0 is the same as last_reset == 1 or last_reset ==
> -1.

But some codes rely on zero value to keep track on the delay being not
valid. If 0 and 1 are the same, just have to prevent jiffies from being 0
by jumping to 1 after ~0ul and you will get a nice 0=1 condition that will
make happy all codes relying on some zero kernel time value. :-)

> >This comment does not make sense for a variable that wraps around.
>
> Woops, I think that you have misunderstood the comment or my comments
> sounds bad... ;)

The comment points to a bug or is just useless.

> >By the way, the ncr53c8xx driver assumes that linux will be rebooted
> >before the 497 days uptime that wraps jiffies around.
>
> If this is true

It should not be false. But the jiffies wrap-around problem had been
stated not urgent by Linus. I only want to fix it in time. :)

> (as I just said some time ago), you should at least change
> the:
>
> jiffies++
>
> with
>
> if (!(jiffies+1))
> {
> sync();
> panic("jiffies wrap");
> }
> jiffies++;

Are you sure this change would make any difference? ;-)

> You should also document the thing. I am not aware of a FAQ that say that
> linux has to be resetted on day 497.

I am wondering if humans will really continue using computers after the
Y2K crash which will occur in less time for jiffies to wrap around on
machines running 2.2 kernels. :-)

> I think we are lucky though since the reset-scsi code is the only thing I
> am aware that isn' t jiffy wrap compliant (or at least not trivially
> fixable) right now. I' ll spend my next spare time on it infact.

If you have much spare time, you may have some chance to succeed, IMO. ;-)

> Ideas and comments are always welcome...

Will try to have some.

Regards,
Gerard.


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