On Thu, Apr 04, 2019 at 08:44:11PM +0200, Miroslav Benes wrote: > GCC 9 introduces a new option, -flive-patching. It disables certain > optimizations which could make a compilation unsafe for later live > patching of the running kernel. > > The option is used only if CONFIG_LIVEPATCH is enabled and $(CC) > supports it. > > Performance impact of the option was measured on three different > Intel machines - two bigger NUMA boxes and one smaller UMA box. Kernel > intensive (IO, scheduling, networking) benchmarks were selected, plus a > set of HPC workloads from NAS Parallel Benchmark. The tests were done on > upstream kernel 5.0-rc8 with openSUSE Leap 15.0 userspace. > > The majority of the tests is unaffected. The only significant exception > is the scheduler section which suffers 1-3% degradation. > > Evaluated-by: Giovanni Gherdovich <ggherdovich@xxxxxxx> > Signed-off-by: Miroslav Benes <mbenes@xxxxxxx> > --- > The patch is based on master branch of the livepatching tree on > git.kernel.org. > > Many thanks to Giovanni who ran the whole testing campaign and analyzed > the results. I archived the dashboard and detailed data. If anyone is > interested, we could probably set up a public website somewhere. Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> While we're on the subject, I'm glad to see ongoing activity on klp-convert (though I haven't had a chance to follow the discussions). What's the status of the rest of the needed bits? - kgraft-analysis-tool - will this also be submitted for inclusion in the kernel tree? - Documentation about how to create a patch - The other bits I think Nicolai has been working on to eliminate all the manual steps -- Josh
