Yes, it's better to auto select SCHED_TICKLESS_LIMIT_MAX_SLEEP under config TIMER_ARCH/ALARM_ARCH.
> -----Original Message----- > From: Matias N. <mat...@imap.cc> > Sent: Friday, September 4, 2020 12:09 AM > To: dev@nuttx.apache.org > Subject: Re: max sleep and tickless with no alarm > > Actually, I see this in arch_timer.c/arch_alarm.c: > > # ifndef CONFIG_SCHED_TICKLESS_LIMIT_MAX_SLEEP > # error CONFIG_SCHED_TICKLESS_LIMIT_MAX_SLEEP must be set to use > CONFIG_SCHED_TICKLESS > # endif > > So I think this is somehow being enforced but it is in a really awkward > place. I will open an issue. > > Best, > Matias > > On Thu, Sep 3, 2020, at 01:09, Matias N. wrote: > > Hi, > > question related to other e-mail. Looking at how tickless is handled when > > SCHED_TICKLESS_ALARM is not defined it seems strange > that not specifying maximum is even possible as it cannot be expected that > up_timer_start() will succeed for arbitrarily long timeouts. > In fact, up_timer_start() may fail due to the underlying timer reporting an > error in this case, but this error is only logged to console and > not really handled. On the other hand, if SCHED_TICKLESS_ALARM I see no > reason why sleep should be limited since it is specified in > absolute value in the future. So it seems to me that > CONFIG_SCHED_TICKLESS_LIMIT_MAX_SLEEP should not be an option but > instead the limit be mandatory, and only for when SCHED_TICKLESS_ALARM is not > defined. > > > > Am I thinking this right? > > > > Best, > > Matias