On Fri, 2017-02-10 at 20:07 +0100, Sebastian Andrzej Siewior wrote: > On 2017-02-08 18:41:25 [+0000], Patel, Vedang wrote: > > > > Hi, > Hi, > > > > > The results for the POSIX timers were not as I expected. The > > latency > > for real-time kernel (v4.9.4-rt2) was worse compared to the > > mainline > > kernel (v4.9.4). In almost all the cases, the latency is almost > > doubled > > with the max value reaching about 10 times when performing the > > tests > > under load. > Is it also the case if you boost the priority of ktimersoftd/X > threads? > For clock_nanosleep, the wake-ups happen directly from hard-timer > interrupt. For the posix-timer we have to delay those to the > ktimersoftd > thread which runs usually RT prio 1. > I am getting very similar results even if I change the priority of ktimersoftd to 99. Are there any recent rt patches which might have changed the behaviour of POSIX timers? Also, are POSIX timers really suited for "real-time" applications?I believe a similar question was raised by Ran Shalit a few days back: http://www.spinics.net/lists/linux-rt-users/msg16249.html Thanks, Vedang > > > > Thanks, > > Vedang Patel > > Software Engineer > > Intel Corporation > Sebastian��.n��������+%������w��{.n�����{�����ǫ���ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
