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authorJason Gunthorpe <jgg@mellanox.com>2018-01-29 13:26:40 -0700
committerJason Gunthorpe <jgg@mellanox.com>2018-01-30 09:30:00 -0700
commite7996a9a77fc669387da43ff4823b91cc4872bd0 (patch)
tree617f0a128e222539d67e8cccc359f1bc4b984900 /drivers/cpufreq/cpufreq_governor.c
parentb5fa635aab8f0d39a824c01991266a6d06f007fb (diff)
parentd8a5b80568a9cb66810e75b182018e9edb68e8ff (diff)
downloadtalos-op-linux-e7996a9a77fc669387da43ff4823b91cc4872bd0.tar.gz
talos-op-linux-e7996a9a77fc669387da43ff4823b91cc4872bd0.zip
Merge tag v4.15 of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
To resolve conflicts in: drivers/infiniband/hw/mlx5/main.c drivers/infiniband/hw/mlx5/qp.c From patches merged into the -rc cycle. The conflict resolution matches what linux-next has been carrying. Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/cpufreq/cpufreq_governor.c')
-rw-r--r--drivers/cpufreq/cpufreq_governor.c19
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c
index 58d4f4e1ad6a..ca38229b045a 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -22,6 +22,8 @@
#include "cpufreq_governor.h"
+#define CPUFREQ_DBS_MIN_SAMPLING_INTERVAL (2 * TICK_NSEC / NSEC_PER_USEC)
+
static DEFINE_PER_CPU(struct cpu_dbs_info, cpu_dbs);
static DEFINE_MUTEX(gov_dbs_data_mutex);
@@ -47,11 +49,15 @@ ssize_t store_sampling_rate(struct gov_attr_set *attr_set, const char *buf,
{
struct dbs_data *dbs_data = to_dbs_data(attr_set);
struct policy_dbs_info *policy_dbs;
+ unsigned int sampling_interval;
int ret;
- ret = sscanf(buf, "%u", &dbs_data->sampling_rate);
- if (ret != 1)
+
+ ret = sscanf(buf, "%u", &sampling_interval);
+ if (ret != 1 || sampling_interval < CPUFREQ_DBS_MIN_SAMPLING_INTERVAL)
return -EINVAL;
+ dbs_data->sampling_rate = sampling_interval;
+
/*
* We are operating under dbs_data->mutex and so the list and its
* entries can't be freed concurrently.
@@ -430,7 +436,14 @@ int cpufreq_dbs_governor_init(struct cpufreq_policy *policy)
if (ret)
goto free_policy_dbs_info;
- dbs_data->sampling_rate = cpufreq_policy_transition_delay_us(policy);
+ /*
+ * The sampling interval should not be less than the transition latency
+ * of the CPU and it also cannot be too small for dbs_update() to work
+ * correctly.
+ */
+ dbs_data->sampling_rate = max_t(unsigned int,
+ CPUFREQ_DBS_MIN_SAMPLING_INTERVAL,
+ cpufreq_policy_transition_delay_us(policy));
if (!have_governor_per_policy())
gov->gdbs_data = dbs_data;
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