On Wed 07-10-20 14:04:01, Michal Hocko wrote: > From: Michal Hocko <mho...@suse.com> > > Many people are still relying on pre built distribution kernels and so > distributions have to provide mutliple kernel flavors to offer different > preemption models. Most of them are providing PREEMPT_NONE for typical > server deployments and PREEMPT_VOLUNTARY for desktop users. > > Having two different kernel binaries differing only by the preemption > mode seems rather wasteful and inflexible. Especially when the difference > between PREEMPT_NONE and PREEMPT_VOLUNTARY is really minimal. Both only > allow explicit scheduling points while running in the kernel and it is > only might_sleep which adds additional preemption points for > PREEMPT_VOLUNTARY. > > Add a kernel command line parameter preempt_mode=[none, voluntary] which > allows to override the default compile time preemption mode > (CONFIG_PREEMPT_NONE resp. CONFIG_PREEMPT_VOLUTARY). Voluntary preempt > mode is guarded by a jump label to prevent any potential runtime overhead. > > Signed-off-by: Michal Hocko <mho...@suse.com> > --- > > Hi all, > this is sent as an RFC because it still needs some work. E.g. move jump > label changes into their own patch. They are needed mostly to get rid of > header files dependencies (seen for CONFIG_JUMP_LABEL=n via atomic.h -> > bug.h). > > I wanted to make sure that the idea is sound for maintainers first. The > next step would be extending the command line to support full preemption > as well but there is much more work in that area. Frederic has promissed > to look into that. > > Thoughts?
Is there any additional feedback? Should I split up the patch and repost for inclusion? -- Michal Hocko SUSE Labs