Le 17/02/2022 à 08:04, Joel Stanley a écrit : > x86 added a control for turning SMT on and off in commit 05736e4ac13c > ("cpu/hotplug: Provide knobs to control SMT"). > > Implement this for powerpc as an alternative to the currently method of > iterating through /sys/devices/system/cpu/cpuN/online for every CPU. > > # ppc64_cpu --info > Core 0: 0* 1* 2* 3* 4* 5* 6* 7* > Core 1: 8* 9* 10* 11* 12* 13* 14* 15* > # grep . /sys/devices/system/cpu/smt/* > /sys/devices/system/cpu/smt/active:1 > /sys/devices/system/cpu/smt/control:on > # echo off > /sys/devices/system/cpu/smt/control > # ppc64_cpu --info > Core 0: 0* 1 2 3 4 5 6 7 > Core 1: 8* 9 10 11 12 13 14 15 > # grep . /sys/devices/system/cpu/smt/* > /sys/devices/system/cpu/smt/active:0 > /sys/devices/system/cpu/smt/control:off > > Signed-off-by: Joel Stanley <j...@jms.id.au>
Build fails with corenet64_smp_defconfig: CC kernel/cpu.o kernel/cpu.c: In function 'cpuhp_smt_disable': kernel/cpu.c:2220:23: error: implicit declaration of function 'cpu_down_maps_locked' [-Werror=implicit-function-declaration] 2220 | ret = cpu_down_maps_locked(cpu, CPUHP_OFFLINE); | ^~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors make[1]: *** [scripts/Makefile.build:288: kernel/cpu.o] Error 1 Christophe