Linux 6.5 Workqueues Add Automatic CPU-Intensive Detection & Monitoring

[phoronix]

Phoronix: Linux 6.5 Workqueues Add Automatic CPU-Intensive Detection & Monitoring

Tejun Heo ;ast week submitted the workqueue changes for the Linux 6.5 kernel and they include an interesting addition...

https://www.phoronix.com/news/Linux-6.5-Workqueues

[tildearrow]

Typo in first line
Typo in second line as well :>

[mathieu.cossette]

Keep them coming ! News like this one is awesome for acquiring new users of Linux distributions .

[coder]

What do they mean by "work items" ? Is this just another name for threads/LWPs? Or something else?

[Alpha64]

What do they mean by "work items" ? Is this just another name for threads/LWPs? Or something else?

A work item is basically a pointer to a function that is being run by a workqueue. You can find more information about work items and Workqueues here:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/core-api/workqueue.rst

(Note: This link should include the changes this patch introduced)

As noted in that link:

A work item is a simple struct that holds a pointer to the function
that is to be executed asynchronously. Whenever a driver or subsystem
wants a function to be executed asynchronously it has to set up a work
item pointing to that function and queue that work item on a
workqueue.

As this should make clear, Workqueues are kernel-level constructs that run kernelspace code.

[coder]

As this should make clear, Workqueues are kernel-level constructs that run kernelspace code.

Ah, okay.

Rats. I've long thought we needed something like that for userspace. It seems to me that the approach of forcing userspace code to spin up its own worker threads is archaic, tedious, and doesn't scale well.