tree ec535aced7cdf7390290a4bf61402346b166c07b
parent 0d557dc97f4bb501f086a03d0f00b99a7855d794
author Heiko Carstens <heiko.carstens@de.ibm.com> 1223934610 +0200
committer Rusty Russell <rusty@rustcorp.com.au> 1224630026 +1100

stop_machine: use workqueues instead of kernel threads

Convert stop_machine to a workqueue based approach. Instead of using kernel
threads for stop_machine we now use a an rt workqueue to synchronize all
cpus.
This has the advantage that all needed per cpu threads are already created
when stop_machine gets called. And therefore a call to stop_machine won't
fail anymore. This is needed for s390 which needs a mechanism to synchronize
all cpus without allocating any memory.
As Rusty pointed out free_module() needs a non-failing stop_machine interface
as well.

As a side effect the stop_machine code gets simplified.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>