Messages in this thread | | | Date | Thu, 24 Jan 2013 12:13:40 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH] Add Intel Ivy bridge CPU flags |
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On Thu, Jan 24, 2013 at 11:53:43AM +0100, Michal Marek wrote: > On Wed, Jan 23, 2013 at 06:43:17PM +0100, Alec Bickerton wrote: > > Hi, > > > > I'd like to submit the attached patch to add Ivy Bridge processor support to the > > processor type menu in menuconfig. Setting this configures the appropriate > > CFLAGS (core-avx-i) for ivy bridge. > > > > As this is my first kbuild patch, could somebody review it and let me know what > > I've done wrong. ;-) > > You sent it to linux-kbuild instead of x86@kernel.org. The kbuild > maintainer is not really knowledgeable about gcc optimisation options ;). > Nevertheless, some random comments are below. Note that I am not > saying if the config option is useful or not.
Normally, such optimizations have a little effect on the kernel because it doesn't normally use fpu stuff and the rest of the instructions we need, we add ourselves (see arch/x86/include/asm/archrandom.h for RDRAND, for example).
So, first we'd need persuasive benchmark numbers which show that a kernel built with core-avx-i is faster at some representative workload than mtune=generic one...
Thanks.
-- Regards/Gruss, Boris.
Sent from a fat crate under my desk. Formatting is fine. --
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