Re: Question Regarding ERMS memcpy

From: Borislav Petkov
Date: Sun Mar 05 2017 - 04:55:00 EST


On Sat, Mar 04, 2017 at 09:58:14PM -0700, Logan Gunthorpe wrote:
> So, I've found that my kernel config had the OPTIMIZE_FOR_SIZE selected
> instead of OPTIMIZE_FOR_PERFORMANCE. I'm not sure why that is but
> switching to the latter option fixes my problem. A memcpy call is used
> instead of the poor inline solution. (I'm not really sure how the inline
> solution even makes any sense as it almost certainly makes things larger
> in the grand scheme of things.)

Probably some gcc heuristics don't work as expected...

In any case, I have

# CONFIG_CC_OPTIMIZE_FOR_SIZE is not set

here and it still generates REP; MOVSL in dmi_scan_machine().

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Boris.

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