On Wed, 10 Nov 2021 04:20:52 +0000 Tyler Retzlaff <roret...@microsoft.com> wrote:
> > > > > > High performance applications benefit from an option to raise the > > > priority of their threads to avoid being preemted by other threads on > > > the system. If there are issues with realtime priority on some of the > > > platforms, maybe we can add a warning for the user to make them aware > > > of possible crashes as Stephen H. suggested some time ago. Note that > > > this patch doesn't change the priority of EAL threads, enabling the > > > higher priority will be done through a command line option when starting > > > the application. > > > Maybe we can explore raising the priority but not to the realtime level. > > > Let me put it more succulently. > > Almost all DPDK applications have threads that are a 100% CPU doing polling. > > Putting those thread as real-time thread breaks Linux badly because the > > kernel can and will try and run work on those CPU's and the system is > > broken/unstable/dead at that point. > > The suggestion is that when running on Windows it should be possible for the > application to be configured to use real-time threads, there is no > implication that it will force real-time priority on Linux. If it doesn't > make sense for it to be configured on Linux then don't configure it. But > saying it shall not be configurable for any platform just because one > platform can't make use of the configuration and those platforms have to run > compromised makes little sense. Linux administrators are (or should be) > knowledgeable enough to know what configuration to use. > Why not just make it always return an error when real-time is requested on Linux from a DPDK thread. The experience on the mailing list is that users will find trouble. Maybe it is just that the sampling is biased. Users that are knowledgeable or figure out problems themselves don't come to the mailing list.
