Files
android_kernel_xiaomi_sm8450/arch/powerpc/kernel
Anton Blanchard 152d523e63 powerpc: Create context switch helpers save_sprs() and restore_sprs()
Move all our context switch SPR save and restore code into two
helpers. We do a few optimisations:

- Group all mfsprs and all mtsprs. In many cases an mtspr sets a
scoreboarding bit that an mfspr waits on, so the current practise of
mfspr A; mtspr A; mfpsr B; mtspr B is the worst scheduling we can
do.

- SPR writes are slow, so check that the value is changing before
writing it.

A context switch microbenchmark using yield():

http://ozlabs.org/~anton/junkcode/context_switch2.c

./context_switch2 --test=yield 0 0

shows an improvement of almost 10% on POWER8.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 13:52:24 +11:00
..
2014-11-27 09:32:58 +11:00
2014-08-13 15:13:42 +10:00
2014-09-25 23:14:46 +10:00
2014-11-03 12:12:32 +11:00
2014-11-03 12:12:32 +11:00
2015-08-06 15:10:20 +10:00
2015-10-27 18:13:30 -05:00
2015-03-24 13:15:52 +11:00
2014-09-25 23:14:41 +10:00
2014-08-06 13:04:32 +02:00
2012-03-28 18:30:02 +01:00
2015-04-07 17:15:13 +10:00
2015-06-24 17:49:38 -07:00