CVS commit: src

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Wed Aug  9 08:23:13 UTC 2023

Modified Files:
        src/sys/kern: subr_workqueue.c
        src/tests/rump/rumpkern: t_workqueue.c

Log Message:
workqueue(9): Avoid touching running work items in workqueue_wait.

As soon as the workqueue function has called, it is forbidden to
touch the struct work passed to it -- the function might free or
reuse the data structure it is embedded in.

So workqueue_wait is forbidden to search the queue for the batch of
running work items.  Instead, use a generation number which is odd
while the thread is processing a batch of work and even when not.

There's still a small optimization available with the struct work
pointer to wait for: if we find the work item in one of the per-CPU
_pending_ queues, then after we wait for a batch of work to complete
on that CPU, we don't need to wait for work on any other CPUs.

PR kern/57574

XXX pullup-10
XXX pullup-9
XXX pullup-8


To generate a diff of this commit:
cvs rdiff -u -r1.41 -r1.42 src/sys/kern/subr_workqueue.c
cvs rdiff -u -r1.3 -r1.4 src/tests/rump/rumpkern/t_workqueue.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.