slub checks for poison one byte by one, which is highly inefficient
and shows up frequently as a highest cpu-eater in perf top.
Joining reads gives nice speedup:
(Compiling some project with different options)
make -j12 make clean
slub_debug disabled: 1m 27s 1.2 s
slub_debug enabled: 1m 46s 7.6 s
slub_debug enabled + this patch: 1m 33s 3.2 s
check_bytes still shows up high, but not always at the top.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Matt Mackall <mpm@selenic.com> Cc: linux-mm@kvack.org Signed-off-by: Pekka Enberg <penberg@kernel.org>