[tip:sched/core] sched/x86: Remove broken power estimation

tip-bot for Peter Zijlstra
2012-07-24T14:14:16Z

Commit-ID: ee08d1284ea9235b29bd2d9b7493b4b4cf3da09c
Gitweb: http://git.kernel.org/tip/ee08d1284ea9235b29bd2d9b7493b4b4cf3da09c
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Wed, 13 Jun 2012 15:24:45 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 24 Jul 2012 13:53:00 +0200

sched/x86: Remove broken power estimation

The x86 sched power implementation has been broken forever and gets in
the way of other stuff, remove it.

[ For archaeological interest, fixing this code would require dealing
with the cross-cpu calling of these functions and more importantly, we
need to filter idle time out of the a/m-perf stuff because the ratio
will go down to 0 when idle, giving a 0 capacity which is not what
we'd want. ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Link: http://lkml.kernel.org/r/1339594110.8980.38.camel@twins
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/cpu/Makefile | 2 +-
arch/x86/kernel/cpu/sched.c | 55 ------------------------------------------
2 files changed, 1 insertions(+), 56 deletions(-)

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 6ab6aa2..c598126 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -14,7 +14,7 @@ CFLAGS_common.o := $(nostackp)

obj-y := intel_cacheinfo.o scattered.o topology.o
obj-y += proc.o capflags.o powerflags.o common.o
-obj-y += vmware.o hypervisor.o sched.o mshyperv.o
+obj-y += vmware.o hypervisor.o mshyperv.o
obj-y += rdrand.o
obj-y += match.o

diff --git a/arch/x86/kernel/cpu/sched.c b/arch/x86/kernel/cpu/sched.c
deleted file mode 100644
index a640ae5..0000000
--- a/arch/x86/kernel/cpu/sched.c
+++ /dev/null
@@ -1,55 +0,0 @@
-#include <linux/sched.h>
-#include <linux/math64.h>
-#include <linux/percpu.h>
-#include <linux/irqflags.h>
-
-#include <asm/cpufeature.h>
-#include <asm/processor.h>
-
-#ifdef CONFIG_SMP
-
-static DEFINE_PER_CPU(struct aperfmperf, old_perf_sched);
-
-static unsigned long scale_aperfmperf(void)
-{
- struct aperfmperf val, *old = &__get_cpu_var(old_perf_sched);
- unsigned long ratio, flags;
-
- local_irq_save(flags);
- get_aperfmperf(&val);
- local_irq_restore(flags);
-
- ratio = calc_aperfmperf_ratio(old, &val);
- *old = val;
-
- return ratio;
-}
-
-unsigned long arch_scale_freq_power(struct sched_domain *sd, int cpu)
-{
- /*
- * do aperf/mperf on the cpu level because it includes things
- * like turbo mode, which are relevant to full cores.
- */
- if (boot_cpu_has(X86_FEATURE_APERFMPERF))
- return scale_aperfmperf();
-
- /*
- * maybe have something cpufreq here
- */
-
- return default_scale_freq_power(sd, cpu);
-}
-
-unsigned long arch_scale_smt_power(struct sched_domain *sd, int cpu)
-{
- /*
- * aperf/mperf already includes the smt gain
- */
- if (boot_cpu_has(X86_FEATURE_APERFMPERF))
- return SCHED_LOAD_SCALE;
-
- return default_scale_smt_power(sd, cpu);
-}
-
-#endif