2016-10-07 22:59:33

by Aaro Koskinen

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Subject: v4.8 cpufreq regression?

Hi,

I'm upgrading from v4.7 to v4.8 on MIPS/loongson2_cpufreq with
cpufreq/ondemand and I noticed that /proc/cpuinfo is always reporting
(regardless of system load):

BogoMIPS : 697150.20

and sysfs:

/sys/devices/system/cpu/cpufreq/policy0/affected_cpus:0
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_cur_freq:797800
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_max_freq:797800
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_min_freq:199450
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_transition_latency:0
/sys/devices/system/cpu/cpufreq/policy0/related_cpus:0
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_frequencies:199450 299175 398900 498625 598350 698075 797800
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_governors:ondemand performance
/sys/devices/system/cpu/cpufreq/policy0/scaling_cur_freq:797800
/sys/devices/system/cpu/cpufreq/policy0/scaling_driver:loongson2
/sys/devices/system/cpu/cpufreq/policy0/scaling_governor:ondemand
/sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq:797800
/sys/devices/system/cpu/cpufreq/policy0/scaling_min_freq:199450
/sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed:<unsupported>

although previously they reported (when idle):

BogoMIPS : 132.09

/sys/devices/system/cpu/cpufreq/policy0/affected_cpus:0
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_cur_freq:199445
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_max_freq:797780
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_min_freq:199445
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_transition_latency:0
/sys/devices/system/cpu/cpufreq/policy0/related_cpus:0
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_frequencies:199445 299167 398890 498612 598335 698057 797780
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_governors:ondemand performance
/sys/devices/system/cpu/cpufreq/policy0/scaling_cur_freq:199445
/sys/devices/system/cpu/cpufreq/policy0/scaling_driver:loongson2
/sys/devices/system/cpu/cpufreq/policy0/scaling_governor:ondemand
/sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq:797780
/sys/devices/system/cpu/cpufreq/policy0/scaling_min_freq:199445
/sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed:<unsupported>

and under full load:

BogoMIPS : 528.38

/sys/devices/system/cpu/cpufreq/policy0/affected_cpus:0
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_cur_freq:797780
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_max_freq:797780
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_min_freq:199445
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_transition_latency:0
/sys/devices/system/cpu/cpufreq/policy0/related_cpus:0
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_frequencies:199445 299167 398890 498612 598335 698057 797780
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_governors:ondemand performance
/sys/devices/system/cpu/cpufreq/policy0/scaling_cur_freq:797780
/sys/devices/system/cpu/cpufreq/policy0/scaling_driver:loongson2
/sys/devices/system/cpu/cpufreq/policy0/scaling_governor:ondemand
/sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq:797780
/sys/devices/system/cpu/cpufreq/policy0/scaling_min_freq:199445
/sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed:<unsupported>

The offeding commit (bisected) seems to be:

commit da0c6dc00c69d0adaae99c3b3d2ea0c869a3fb35
Author: Viresh Kumar <[email protected]>
Date: Mon Jun 27 16:04:07 2016 +0530

cpufreq: Handle sorted frequency tables more efficiently

Any ideas?

A.


2016-10-10 21:38:21

by Aaro Koskinen

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Subject: [PATCH] cpufreq: skip invalid entries when searching the frequency

Skip invalid entries when searching the frequency. This fixes cpufreq
at least on loongson2 MIPS board.

Fixes: da0c6dc00c69 ("cpufreq: Handle sorted frequency tables more efficiently")
Signed-off-by: Aaro Koskinen <[email protected]>
---
include/linux/cpufreq.h | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 631ba33b..0c1b188 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -645,6 +645,9 @@ static inline int cpufreq_table_find_index_al(struct cpufreq_policy *policy,
for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
freq = table[i].frequency;

+ if (freq == CPUFREQ_ENTRY_INVALID)
+ continue;
+
if (freq >= target_freq)
return i;

@@ -665,6 +668,9 @@ static inline int cpufreq_table_find_index_dl(struct cpufreq_policy *policy,
for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
freq = table[i].frequency;

+ if (freq == CPUFREQ_ENTRY_INVALID)
+ continue;
+
if (freq == target_freq)
return i;

@@ -706,6 +712,9 @@ static inline int cpufreq_table_find_index_ah(struct cpufreq_policy *policy,
for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
freq = table[i].frequency;

+ if (freq == CPUFREQ_ENTRY_INVALID)
+ continue;
+
if (freq == target_freq)
return i;

@@ -735,6 +744,9 @@ static inline int cpufreq_table_find_index_dh(struct cpufreq_policy *policy,
for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
freq = table[i].frequency;

+ if (freq == CPUFREQ_ENTRY_INVALID)
+ continue;
+
if (freq <= target_freq)
return i;

@@ -767,6 +779,9 @@ static inline int cpufreq_table_find_index_ac(struct cpufreq_policy *policy,
for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
freq = table[i].frequency;

+ if (freq == CPUFREQ_ENTRY_INVALID)
+ continue;
+
if (freq == target_freq)
return i;

@@ -800,6 +815,9 @@ static inline int cpufreq_table_find_index_dc(struct cpufreq_policy *policy,
for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
freq = table[i].frequency;

+ if (freq == CPUFREQ_ENTRY_INVALID)
+ continue;
+
if (freq == target_freq)
return i;

--
2.9.2

2016-10-12 03:17:54

by Viresh Kumar

[permalink] [raw]
Subject: Re: [PATCH] cpufreq: skip invalid entries when searching the frequency

On 11-10-16, 00:38, Aaro Koskinen wrote:
> Skip invalid entries when searching the frequency. This fixes cpufreq
> at least on loongson2 MIPS board.
>
> Fixes: da0c6dc00c69 ("cpufreq: Handle sorted frequency tables more efficiently")
> Signed-off-by: Aaro Koskinen <[email protected]>
> ---
> include/linux/cpufreq.h | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)

Hi Aaro,

I have sent a new version of this patch, but screwed up the
--in-reply-to somehow.. Can you please give that a try?

--
viresh