This is a note to let you know that I've just added the patch titled
thermal: intel: powerclamp: Fix cur_state for multi package system
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
thermal-intel-powerclamp-fix-cur_state-for-multi-package-system.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 8e47363588377e1bdb65e2b020b409cfb44dd260 Mon Sep 17 00:00:00 2001
From: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Date: Wed, 1 Feb 2023 12:39:41 -0800
Subject: thermal: intel: powerclamp: Fix cur_state for multi package system
From: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
commit 8e47363588377e1bdb65e2b020b409cfb44dd260 upstream.
The powerclamp cooling device cur_state shows actual idle observed by
package C-state idle counters. But the implementation is not sufficient
for multi package or multi die system. The cur_state value is incorrect.
On these systems, these counters must be read from each package/die and
somehow aggregate them. But there is no good method for aggregation.
It was not a problem when explicit CPU model addition was required to
enable intel powerclamp. In this way certain CPU models could have
been avoided. But with the removal of CPU model check with the
availability of Package C-state counters, the driver is loaded on most
of the recent systems.
For multi package/die systems, just show the actual target idle state,
the system is trying to achieve. In powerclamp this is the user set
state minus one.
Also there is no use of starting a worker thread for polling package
C-state counters and applying any compensation for multiple package
or multiple die systems.
Fixes: b721ca0d1927 ("thermal/powerclamp: remove cpu whitelist")
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Cc: 4.14+ <stable@xxxxxxxxxxxxxxx> # 4.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/thermal/intel_powerclamp.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
--- a/drivers/thermal/intel_powerclamp.c
+++ b/drivers/thermal/intel_powerclamp.c
@@ -72,6 +72,7 @@
static unsigned int target_mwait;
static struct dentry *debug_dir;
+static bool poll_pkg_cstate_enable;
/* user selected target */
static unsigned int set_target_ratio;
@@ -280,6 +281,9 @@ static unsigned int get_compensation(int
{
unsigned int comp = 0;
+ if (!poll_pkg_cstate_enable)
+ return 0;
+
/* we only use compensation if all adjacent ones are good */
if (ratio == 1 &&
cal_data[ratio].confidence >= CONFIDENCE_OK &&
@@ -552,7 +556,8 @@ static int start_power_clamp(void)
control_cpu = cpumask_first(cpu_online_mask);
clamping = true;
- schedule_delayed_work(&poll_pkg_cstate_work, 0);
+ if (poll_pkg_cstate_enable)
+ schedule_delayed_work(&poll_pkg_cstate_work, 0);
/* start one kthread worker per online cpu */
for_each_online_cpu(cpu) {
@@ -621,11 +626,15 @@ static int powerclamp_get_max_state(stru
static int powerclamp_get_cur_state(struct thermal_cooling_device *cdev,
unsigned long *state)
{
- if (true == clamping)
- *state = pkg_cstate_ratio_cur;
- else
+ if (clamping) {
+ if (poll_pkg_cstate_enable)
+ *state = pkg_cstate_ratio_cur;
+ else
+ *state = set_target_ratio;
+ } else {
/* to save power, do not poll idle ratio while not clamping */
*state = -1; /* indicates invalid state */
+ }
return 0;
}
@@ -770,6 +779,9 @@ static int __init powerclamp_init(void)
goto exit_unregister;
}
+ if (topology_max_packages() == 1)
+ poll_pkg_cstate_enable = true;
+
cooling_dev = thermal_cooling_device_register("intel_powerclamp", NULL,
&powerclamp_cooling_ops);
if (IS_ERR(cooling_dev)) {
Patches currently in stable-queue which might be from srinivas.pandruvada@xxxxxxxxxxxxxxx are
queue-4.19/thermal-intel-powerclamp-fix-cur_state-for-multi-package-system.patch
