[PATCH v5 09/21] powerpc/64: context tracking remove _TIF_NOHZ

[Nicholas Piggin]

Excerpts from Christophe Leroy's message of January 14, 2021 12:50 am:
> 
> 
> Le 13/01/2021 à 08:32, Nicholas Piggin a écrit :
>> Add context tracking to the system call handler explicitly, and remove
>> _TIF_NOHZ.
>> 
>> This saves 35 cycles on gettid system call cost on POWER9 with a
>> CONFIG_NOHZ_FULL kernel.
> 
> 35 cycles among 100 cycles, or among 5000 cycles ? I meant what pourcentage to you win ?

I can re-check when I update and retest. On the order of about 500
IIRC, so quite significant proportion of the cost.

Thanks,
Nick