On 22/07/2025 11:02, Johannes Berg wrote:
On Tue, 2025-07-22 at 11:00 +0200, Antonio Quartulli wrote:
So I think if anything we should worry about the
if (time_is_after_jiffies(timeout) &&
time_after(timeout, latest_timeout))
latest_timeout = timeout;
comparison, but for that just unconditionally setting it to 0 is really
the wrong thing to do, since it means you compare to an arbitrary time
zero here?
We are looking for the maximum timeout, so using 0 (minimum possible
value) as base line should be what we want, no?
[note: I am assuming 0 is not a possible timeout value]
That assumption is wrong, in fact jiffies starts at a slightly negative
value (about 5 minutes?) so that a few minutes after boot the time goes
to the perfectly valid value zero. And on HZ=1000 32-bit systems, this
situation of course reappears every ~49.7 days.
As discussed on IRC, also the caller of this function is wrongly
assuming that returning 0 means "no timeout planned".
For this reason I'll send v2 where I will initialize latest_timeout to
jiffies and I will re-arrange surrounding checks accordingly (caller
included).
Regards,
--
Antonio Quartulli
CEO and Co-Founder
Mandelbit Srl
https://www.mandelbit.com
