diff options
| author | Preeti U Murthy <preeti@linux.vnet.ibm.com> | 2014-04-10 09:15:12 +0530 |
|---|---|---|
| committer | Eli Qiao <taget@linux.vnet.ibm.com> | 2014-04-10 12:28:26 +0800 |
| commit | cf05d568d7b8bda30561d86976df73c16c17b42a (patch) | |
| tree | 14524923f6ed2f8fc6ecc60cd16d1fadd72725c4 | |
| parent | fe93cac67c196c1cb7501a1ccbf18e12d1f50861 (diff) | |
| download | powerkvm-cf05d568d7b8bda30561d86976df73c16c17b42a.tar.gz | |
kvm: Set the runlatch bits correctly for offline cpus
Up until now we have been setting the runlatch bits for a busy CPU and
clearing it when a CPU enters idle state. The runlatch bit has thus
been consistent with the utilization of a CPU as long as the CPU is online.
However when a CPU is hotplugged out the runlatch bit is not cleared. It
needs to be cleared to indicate an unused CPU. OCC consumes the runlatch bit
to decide the utilization of a thread and ends up seeing the offline threads
as busy. Hence this patch has the runlatch bit cleared for an offline CPU
just before entering an idle state and sets it immediately after it exits
the idle state.
Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
| -rw-r--r-- | arch/powerpc/platforms/powernv/smp.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c index 90be045cf02f02..d2592d8914f5ee 100644 --- a/arch/powerpc/platforms/powernv/smp.c +++ b/arch/powerpc/platforms/powernv/smp.c @@ -30,6 +30,7 @@ #include <asm/cputhreads.h> #include <asm/xics.h> #include <asm/opal.h> +#include <asm/runlatch.h> #include "powernv.h" @@ -172,7 +173,9 @@ static void pnv_smp_cpu_kill_self(void) */ mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1); while (!generic_check_cpu_restart(cpu)) { + ppc64_runlatch_off(); power7_nap(); + ppc64_runlatch_on(); if (!cpu_core_split_required()) { if (generic_check_cpu_restart(cpu)) |