Re: Question Regarding ERMS memcpy

From: Logan Gunthorpe
Date: Mon Mar 06 2017 - 12:41:13 EST




On 06/03/17 12:28 AM, H. Peter Anvin wrote:
> On 03/05/17 23:01, Logan Gunthorpe wrote:
>>
>> On 05/03/17 12:54 PM, Borislav Petkov wrote:
>>> Logan, wanna give that a try, see if it takes care of your issue?
>>
>> Well honestly my issue was solved by fixing my kernel config. I have no
>> idea why I had optimize for size in there in the first place.
>>
>
> Yes, to gcc "optimize for size" means exactly that... intended for cases
> where saving storage (e.g. ROM) or code download time is paramount.

I agree and understand, however placing a poorly performing _inline_
memcpy instead of a single call instruction to a performant memcopy
probably took more code space in the end. So like Linus, I just have to
scratch my head at the -Os optimization option.

Logan