The feature branch 'fix-taskq' in Linux's ZFS tree changes the taskq_dispatch()
flag from TQ_SLEEP to TQ_NOSLEEP to avoid sleeping in some circumstances.
However, this has the side effect that taskq_dispatch() now may fail, and since
the return code was not even being checked, it could lead to zio's not being
scheduled to execute.
I'm fixing this in a simplistic but not very elegant way, by just looping until
taskq_dispatch() succeeds.
Signed-off-by: Ricardo M. Correia <ricardo.correia@oracle.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
There are cases where under Linux it is not safe to sleep in
taskq_dispatch(). Rather than adding Linux specific code to
detect these cases I opted to keep it simple and just never
allow a sleep here. The impact of this should be minimal.
Updated fix to detect if we are in an interrupt and only sleep if it
is safe to do some. I guess it must be safe to sleep under Solaris
this must be handled in a sort interrupt handler there
Brian Behlendorf
Ned Bass
Ricardo M. Correia