On 10/11/2023 6:09 PM, Guenter Roeck wrote:
On Wed, Oct 11, 2023 at 10:45:03AM +0000, Ben Shaul, Almog wrote:
Hi all,
We'd like to collect hwmon sensors and get their min/max/avg for our platforms.
Those sensors doesn't support min/max by HW and only support reading current values (they also don't support avg but that is likely the case for all other devices).
For that goal of getting min/max/avg we have two options:
1. Write userspace service that will constantly read the values and do the calculations (and later report to our database)
Yes, this is what you'll have to do.
We appreciate the prompt response!
2. Extend HWMON subsystem/library so each registering hwmon device will ask the subsystem to do it for you.
Then kernel will create workqueue and constantly read the values and make the calculations (which shall later be readable via hwmon sysfs)
No. This would add runtime overhead to each hwmon device even if the
information is not used (which would be the case for almost every user).
That is a fair point.
What about enabling this during runtime in case user will want to
utilize this?
e.g. ioctl/sysfs/debugfs
Of course users can configure the interval during runtime (or even
devfreq based?).
The only concern we had for doing it from usrespace is the short
interval (and multiple sensors) required will create overhead. Of course
doing that in kernel space doesn't make this overhead go away and even
worsen it as we don't go via scheduler. (but does ease
userspace/kernelspace context switch).
And of course the added value of contributing such a feature which does
make sense as probably many want to know across their HW what is the
power consumption. are you aware of some package that supply this kind
of info? or everyone interested is doing some sort of home made solution?
Guenter
