korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-25 05:04:09 +08:00
Code Issues Packages Projects Releases Wiki Activity

hwmon: (coretemp) avoid RDMSR interrupts to isolated CPUs

Browse Source 
The coretemp driver uses rdmsr_on_cpu calls to read
MSR_IA32_PACKAGE_THERM_STATUS/MSR_IA32_THERM_STATUS registers,
which contain information about current core temperature.

For certain low latency applications, the RDMSR interruption exceeds
the applications requirements.

So do not create core files in sysfs, for CPUs which have
isolation and nohz_full enabled.

Temperature information from the housekeeping cores should be
sufficient to infer die temperature.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Link: https://lore.kernel.org/r/Y5zT6B1mY9/pnwJV@tpad
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Marcelo Tosatti 2022-12-16 17:24:08 -03:00 committed by Guenter Roeck
parent e247510e1b
commit 0f8b916bc5
1 changed files with 4 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/hwmon/coretemp.c
View File

@ -27,6 +27,7 @@
#include <asm/msr.h>
#include <asm/processor.h>
#include <asm/cpu_device_id.h>
#include <linux/sched/isolation.h>
#define DRVNAME "coretemp"
@ -502,6 +503,9 @@ static int create_core_data(struct platform_device *pdev, unsigned int cpu,
u32 eax, edx;
int err, index, attr_no;
if (!housekeeping_cpu(cpu, HK_TYPE_MISC))
return 0;
/*
* Find attr number for sysfs:
* We map the attr number to core id of the CPU