Re: -mm seems significanty slower than mainline on kernbench

[Andrew Morton <akpm@osdl.org>]

Martin Bligh <mbligh@google.com> wrote:
>
> > Well, 1% slower.  -mm has permanent not-for-linus debug things, some of
> > which are expected to have a performance impact.  I don't know whether
> > they'd have a 1% impact though.
> 
> OK, fair enough. Can I turn them off somehow to check? it's 10% on 
> NUMA-Q. The good news is that it's stayed in -mm for long time, so ...
> am praying.

There are quite a lot of them.

list_del-debug.patch
page-owner-tracking-leak-detector.patch
page-owner-tracking-leak-detector-fix.patch
unplug-can-sleep.patch
firestream-warnings.patch
#periodically-scan-redzone-entries-and-slab-control-structures.patch
slab-leak-detector.patch
releasing-resources-with-children.patch
nr_blockdev_pages-in_interrupt-warning.patch
nmi-lockup-and-altsysrq-p-dumping-calltraces-on-_all_-cpus.patch
detect-atomic-counter-underflows.patch
sysfs-crash-debugging.patch
device-suspend-debug.patch
slab-cache-shrinker-statistics.patch
slab-cache-shrinker-statistics-fix.patch
mm-debug-dump-pageframes-on-bad_page.patch
debug-warn-if-we-sleep-in-an-irq-for-a-long-time.patch
debug-shared-irqs.patch
debug-shared-irqs-fix.patch
make-frame_pointer-default=y.patch


list_del-debug.patch, detect-atomic-counter-underflows.patch,
slab-cache-shrinker-statistics.patch will all have a small impact.

But not much.