From: "Peter T. Breuer" <ptb@inv.it.uc3m.es>
Message-Id: <200603280357.k2S3vBk14437@inv.it.uc3m.es>
Subject: Re: uptime increases during suspend
In-Reply-To: <44286783.9000709@tremplin-utc.net> from "Eric Piel" at "Mar 28,
 2006 00:30:27 am"
To: "Eric Piel" <Eric.Piel@tremplin-utc.net>
Date: Tue, 28 Mar 2006 05:57:11 +0200 (MET DST)
CC: "Peter T. Breuer" <ptb@inv.it.uc3m.es>,
       "john stultz" <johnstul@us.ibm.com>, linux-kernel@vger.kernel.org
Reply-To: ptb@inv.it.uc3m.es
Reply-By: Sat, 1 Apr 2006 14:21:08 -0700
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1250
Lines: 33

"Also sprach Eric Piel:"
> monotonic clock. Linux has such thing since few releases. Using 
> CLOCK_MONOTONIC (cf "man 3 clock_gettime") may look much less hacky than 
> using the uptime ;-)

Actually, the man page does not say anything about the behavior across
suspends, and ...

      CLOCK_REALTIME
              System-wide  realtime clock.  Setting this clock requires appro-
              priate privileges.

       CLOCK_MONOTONIC
              Clock that cannot be set and  represents  monotonic  time  since
              some unspecified starting point.

I'd understand both those wordings the same way!  Well, I suppose
"cannot be set" means that at least humans can't willingly interfere with
it, but maybe something else can.

> Now... concerning the suspend effect on this clock, I don't know. It's 
> probably the same problem as uptime: no official semantic has ever been 
> stated yet... Does anyone know?

"Monotonic" means "always goes in the same direction", not "never
skips".

Peter
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/