On Tue, Aug 30, 2016 at 02:08:34PM -0500, Kim Phillips wrote: > This 'DEBUG'-prefixed version of PERF_USE_VMALLOC is not used anywhere. > It appears to be leftovers from commit 906010b "perf_event: Provide > vmalloc() based mmap() backing" that introduced it. > > Not sure what commit cb30711 "perf_event: Don't allow vmalloc() backed > perf on powerpc" was trying to do with it either. > > Signed-off-by: Kim Phillips <kim.phill...@arm.com> > Cc: Peter Zijlstra <a.p.zijls...@chello.nl> > Cc: Michael Ellerman <m...@ellerman.id.au> > --- > init/Kconfig | 13 ------------- > 1 file changed, 13 deletions(-) > > diff --git a/init/Kconfig b/init/Kconfig > index cac3f09..934a61f 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -1707,19 +1707,6 @@ config PERF_EVENTS > > Say Y if unsure. > > -config DEBUG_PERF_USE_VMALLOC > - default n > - bool "Debug: use vmalloc to back perf mmap() buffers" > - depends on PERF_EVENTS && DEBUG_KERNEL && !PPC > - select PERF_USE_VMALLOC
^^^^^ It forces the use of vmalloc backed pages for the ring-buffer so that we can test that code on x86, which otherwise doesn't use it.
