On Wed, 2015-09-23 at 15:29 +0200, Michal Marek wrote:
On 2015-09-03 11:26, Michal Marek wrote:
Hi,
since Leap is sharing code with SLE and it will eventually share the kernel as well, I would like to align the config/ directory with the SLE kernel where practical. ia64 has already been deleted, same happened to the trace flavors. We probably want to keep the 32bit ARM, PPC and x86 architectures, to make it easier to build Leap ports for those architectures. What we can drop is the -desktop flavor. Since openSUSE releases have been using this flavor by default, I assume that this is what the majority of users are running, so we probably want to keep some of the settings of the -desktop flavor, to make the transition seamless. Therefore, I propose the following:
- Set CONFIG_PREEMPT=y, CONFIG_HZ=1000 in i386/pae and x86_64/default - Set the sysctl default vm.dirty_ratio=20 for these two flavors - Make i386/pae and x86_64/default obsolete kernel-desktop
So, does anybody oppose this plan? If not, I will push it to master and stable.
I don't see any reason to keep HZ=1000, there are oodles of preempt opportunities in a PREEMPT kernel.
Left for discussion is whether PREEMPT and HZ=1000 are actually worth it even on desktop. The setting can be flipped back later if there is a consensus.
One reason to use the -default setting came to my mind -- if we use CONFIG_PREEMPT_NONE=y and CONFIG_HZ=250, a future Leap kernel will be binary compatible with a future SLES kernel, it will only differ in the SUSE_KERNEL_SUPPORTED setting.
Down side of PREEMPT_NONE is higher scheduling latency across the board. Desktop users may feel the difference under load, may gripe, anybody watching realtime latencies will gripe. -Mike -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org