Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [PATCH] slub: reduce overhead of slub_debug | Date | Thu, 07 Jul 2011 22:23:45 -0700 |
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Christoph Lameter <cl@linux.com> writes:
> +#ifdef __HAVE_ARCH_INV_MEMSCAN > +void *inv_memscan(void *addr, int c, size_t size) > +{ > + if (!size) > + return addr; > + asm volatile("repz; scasb\n\t"
This will just do the slow byte accesses again internally. scasb is not normally very optimized in microcode as far as I know.
Also rep has quite some startup overhead which makes it a bad idea for small sizes (<16-20 or so)
I would stay with the C version. I bet that one is faster.
-Andi
-- ak@linux.intel.com -- Speaking for myself only
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