On Thu, Dec 08 2016, Jinpu Wang wrote:
This number:
> nr_pending = {
> counter = 1
> },
and this number:
> nr_pending = {
> counter = 856
> },
might be interesting.
There are 855 requested on the list. Add the one that is currently
being retried give 856, which is nr_pending for the device that failed.
But nr_pending on the device that didn't fail is 1. I would expect
zero.
When a read or write requests succeeds, rdev_dec_pending() is called
immediately so this should quickly go to zero.
It seems as though there must be a request to the loop device that is
stuck somewhere between the atomic_inc(&rdev->nr_pending) (possibly
inside read_balance) and the call to generic_make_request().
I cannot yet see how that would happen.
Can you check if the is a repeatable observation? Is nr_pending.counter
always '1' on the loop device?
Thanks,
NeilBrown
Attachment:
signature.asc
Description: PGP signature
