Re: advise on future of glibc (mktime issue)

[Nix <nix at esperi dot org dot uk>]

On Tue, 07 Jun 2005, Jairo stated:
> Now, the kernel keeps track of the time and the current timezone, why

The kernel does not know the current timezone.

In any case, since you're calling mktime() so much, /etc/localtime will
be in cache: so you're comparing the cost of a kernel ring transition
and file lookup with the hypothetical cost of a kernel ring transition
and timezone lookup. Even given the open()/close() overhead, I can't
believe you'd gain that much.


Possibly an improvement is to track the time_t at which the timezone was
last checked, and throttle the rate of rechecks to one per minute or
something like that. I don't think millions of checks per second are of
any real use to anyone.

Am I missing something? If not, I'll whip up a patch that does that
(against HEAD, as this is unlikely to be suitable for the stable branch:
I can roll one against 2.3.5 anyway, if Jairo wants).

-- 
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