allow selwakeup to be called from interrupt filter context.
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Authored by adrian on Nov 28 2016, 9:01 PM.

Details

Reviewers

cem
jhb
bapt

Group Reviewers

x11

Summary

The Linux DRM 4.7 work done by Kip minimises changes to the linux code
and one of those changes is that linux interrupts are interrupts, not
deferred.

So driver code that wants to do things like call selwakeup for waking
up sockets (ie, what DRM is doing) is doing it from the interrupt
context, and not deferred into an ithread or tasklet.

This change allows drivers to do it from interrupt filter context.

Diff Detail

Repository

rS FreeBSD src repository - subversion

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Lint Passed

Unit

No Test Coverage

Build Status

Buildable 6087
Build 6349: arc lint + arc unit

Event Timeline

adrian updated this revision to Diff 22587.Nov 28 2016, 9:01 PM

adrian retitled this revision from to allow selwakeup to be called from interrupt filter context..

adrian updated this object.

adrian edited the test plan for this revision. (Show Details)

Herald added a subscriber: imp. · View Herald TranscriptNov 28 2016, 9:01 PM

adrian added reviewers: jhb, bapt, x11.Nov 28 2016, 9:01 PM

cem accepted this revision.Nov 28 2016, 9:04 PM

cem added a reviewer: cem.

This revision is now accepted and ready to land.Nov 28 2016, 9:04 PM

Running arbitrary code from filters is going to break much more than just selwakeup(). FreeBSD's kernel isn't really designed for that model.

Also, have you run this with WITNESS_SKIPSPIN disabled? The lock ordering of spin locks is rather finicky, especially with regards to _sleep() and cv_wait(). msleep_spin() goes to special hoops separate from _sleep() to handle spin locks. cv_wait* do not and assume a non-spin lock. If you are ktracing a thread that sleeps on st_wait this probably panics in a kernel with INVARIANTS and/or WITNESS.

emaste added a subscriber: emaste.Dec 13 2016, 1:28 PM

Looks like jhb's reaciton is controller, but tagging for srcmgr to review.

imp added a project: srcmgr.Aug 9 2025, 10:30 PM