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Re: More on compile performance of Linux kernels in mainline gcc
Jan Hubicka <hubicka@ucw.cz> writes:
>> Andi Kleen <ak@suse.de> writes:
>>
>> > This is an addendum for the numbers for linux kernel compiling
>> > on x86-64 I posted some days ago. gcc tested is the same (041029)
>> > on the same machine with the same kernel tree/configuration.
>>
>> I can't comment on most of this, but:
>>
>> > Looks like the likely/unlikely split is not very effective,
>> > there are a lot of hot unlikely hits.
>>
>> That logic has known bugs. You could try disabling it
>
> I didn't look too closely on Caroline's work, but what bugs do you
> know of?
I don't actually know anything specific.
It occurs to me that one possible explanation for Andi's observations
is that the partitioner decided that the *whole function* belonged in
the cold section. This is a silly thing for it to do, but not out of
the question.
zw