| Message ID | 20220130221944.7992CC340E4@smtp.kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | [PREEMPT_RT,4.19,STABLE] rt: PREEMPT_RT safety net for backported patches | expand |
On 2022-01-30 15:46:27 [-0600], Clark Williams wrote: > While doing some 4.19-rt cleanup work, I stumbled across the fact that parts of > two backported patches were dependent on CONFIG_PREEMPT_RT, rather than > the CONFIG_PREEMPT_RT_FULL used in 4.19 and earlier RT series. The commits > in the linux-stable-rt v4.19-rt branch are: > > dad4c6a33bf4e mm: slub: Don't resize the location tracking cache on PREEMPT_RT > e626b6f873f2c net: Treat __napi_schedule_irqoff() as __napi_schedule() on PREEMPT_RT > > Discussing this at the Stable RT maintainers meeting, Steven Rostedt suggested that > we automagically select CONFIG_PREEMPT_RT if CONFIG_PREEMPT_RT_FULL is on, giving > us a safety net for any subsequently backported patches. Here's my first cut at > that patch. > > I suspect we'll need a similar patch for stable RT kernels < 4.19. > > Suggested-by: Steven Rostedt <rostedt@goodmis.org> > Signed-off-by: Clark Williams <williams@redhat.com> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> > --- > kernel/Kconfig.preempt | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt > index 306567f72a3e..951f58cbd652 100644 > --- a/kernel/Kconfig.preempt > +++ b/kernel/Kconfig.preempt > @@ -6,6 +6,10 @@ config PREEMPT_RT_BASE > bool > select PREEMPT > > +config PREEMPT_RT > + bool > + default false default is false. > + > config HAVE_PREEMPT_LAZY > bool > Sebastian
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt index 306567f72a3e..951f58cbd652 100644 --- a/kernel/Kconfig.preempt +++ b/kernel/Kconfig.preempt @@ -6,6 +6,10 @@ config PREEMPT_RT_BASE bool select PREEMPT +config PREEMPT_RT + bool + default false + config HAVE_PREEMPT_LAZY bool @@ -80,6 +84,7 @@ config PREEMPT_RT_FULL depends on IRQ_FORCED_THREADING select PREEMPT_RT_BASE select PREEMPT_RCU + select PREEMPT_RT help All and everything
While doing some 4.19-rt cleanup work, I stumbled across the fact that parts of two backported patches were dependent on CONFIG_PREEMPT_RT, rather than the CONFIG_PREEMPT_RT_FULL used in 4.19 and earlier RT series. The commits in the linux-stable-rt v4.19-rt branch are: dad4c6a33bf4e mm: slub: Don't resize the location tracking cache on PREEMPT_RT e626b6f873f2c net: Treat __napi_schedule_irqoff() as __napi_schedule() on PREEMPT_RT Discussing this at the Stable RT maintainers meeting, Steven Rostedt suggested that we automagically select CONFIG_PREEMPT_RT if CONFIG_PREEMPT_RT_FULL is on, giving us a safety net for any subsequently backported patches. Here's my first cut at that patch. I suspect we'll need a similar patch for stable RT kernels < 4.19. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Clark Williams <williams@redhat.com> --- kernel/Kconfig.preempt | 5 +++++ 1 file changed, 5 insertions(+)