Re: [patch 38/44] posix-cpu-timers: Respect INFINITY for hard RTTIME limit

From: Ingo Molnar
Date: Mon Aug 19 2019 - 16:06:57 EST



* Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:

> The RTIME limit expiry code does not check the hard RTTIME limit for
> INFINITY, i.e. being disabled. Add it.
>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
> kernel/time/posix-cpu-timers.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/kernel/time/posix-cpu-timers.c
> +++ b/kernel/time/posix-cpu-timers.c
> @@ -905,7 +905,7 @@ static void check_process_timers(struct
> u64 softns, ptime = samples[CPUCLOCK_PROF];
> unsigned long psecs = div_u64(ptime, NSEC_PER_SEC);
>
> - if (psecs >= hard) {
> + if (hard != RLIM_INFINITY && psecs >= hard) {
> /*
> * At the hard limit, we just die.
> * No need to calculate anything else now.

Might make sense to mark this as a possible ABI change in the changelog:
if some weird code learned to rely on this (arguably broken) behavior
then the bug turned into an ABI.

Thanks,

Ingo