Re: [PATCH] RDMA/rxe: Fix a race condition related to the QP error state

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, 2018-01-10 at 16:40 -0500, Doug Ledford wrote:
> On Tue, 2018-01-09 at 11:23 -0800, Bart Van Assche wrote:
> > The following sequence:
> > * Change queue pair state into IB_QPS_ERR.
> > * Post a work request on the queue pair.
> > Triggers the following race condition in the rdma_rxe driver:
> > * rxe_qp_error() triggers an asynchronous call of rxe_completer(), the function
> >   that examines the QP send queue.
> > * rxe_post_send() posts a work request on the QP send queue.
> 
> If rxe_completer() runs before rxe_post_send(), the send queue is
> believed to be empty while a stale work request stays on the send queue
> indefinitely.  To avoid this race, schedule rxe_completer() after a work
> request is queued on a qp in the error state by rxe_post_send().
> 
> I think that improves the log message, yes?
> 

I did some further edits.  But, patch applied to for-next.

-- 
Doug Ledford <dledford@xxxxxxxxxx>
    GPG KeyID: B826A3330E572FDD
    Key fingerprint = AE6B 1BDA 122B 23B4 265B  1274 B826 A333 0E57 2FDD

Attachment: signature.asc
Description: This is a digitally signed message part


[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]