Peter Oskolkov [off-list ref] writes:

On Thu, May 20, 2021 at 2:17 PM Jonathan Corbet [off-list ref] wrote:

quoted

Peter Oskolkov [off-list ref] writes:

quoted

As indicated earlier in the FUTEX_SWAP patchset:

https://lore.kernel.org/lkml/20200722234538.166697-1-posk@posk.io/ (local)

"Google Fibers" is a userspace scheduling framework
used widely and successfully at Google to improve in-process workload
isolation and response latencies. We are working on open-sourcing
this framework, and UMCG (User-Managed Concurrency Groups) kernel
patches are intended as the foundation of this.

So I have to ask...is there *any* documentation out there on what this
is and how people are supposed to use it?  Shockingly, typing "Google
fibers" into Google leads to a less than fully joyful outcome...  This
won't be easy for anybody to review if they have to start by
reverse-engineering what it's supposed to do.

Hi Jonathan,

There is this Linux Plumbers video: https://www.youtube.com/watch?v=KXuZi9aeGTw
And the pdf: http://pdxplumbers.osuosl.org/2013/ocw//system/presentations/1653/original/LPC%20-%20User%20Threading.pdf

I did not reference them in the patchset because links to sites other
than kernel.org are strongly discouraged... I will definitely add a
documentation patch.

I did look at those - but a presentation from 2013 is going to be of
limited relevance for a 2021 patch set.  In particular, the syscall API
appears to have evolved considerably since then.

Feel free to reach out to me directly or through this LKML thread if
you have any questions.

Do you think a documentation patch would be useful at this point, as
opposed to a free-form email discussion?

Documentation patches can help to guide that discussion; they also need
to be reviewed as well.  So yes, I think they should be present from the
beginning.  But then, that's the position I'm supposed to take :)  This
is a big change to the kernel's system-call API, I don't think that
there can be a proper discussion of that without a description of what
you're trying to do.

Thanks,

jon