Thanks Jason.
-----Original Message-----
From: Jason Gunthorpe <jgg@xxxxxxxxxx>
Sent: Thursday, June 30, 2022 6:58 PM
To: Bob Pearson <rpearsonhpe@xxxxxxxxx>
Cc: zyjzyj2000@xxxxxxxxx; Hack, Jenny (Ft. Collins) <jhack@xxxxxxx>; Zago, Frank <frank.zago@xxxxxxx>; linux-rdma@xxxxxxxxxxxxxxx
Subject: Re: [PATCH] RDMA/rxe: Fix deadlock in rxe_do_local_ops()
On Mon, May 23, 2022 at 05:32:52PM -0500, Bob Pearson wrote:
> When a local operation (invalidate mr, reg mr, bind mw) is finished
> there will be no ack packet coming from a responder to cause the wqe
> to be completed. This may happen anyway if a subsequent wqe performs
> IO. Currently if the wqe is signalled the completer tasklet is
> scheduled immediately but not otherwise.
>
> This leads to a deadlock if the next wqe has the fence bit set in send
> flags and the operation is not signalled. This patch removes the
> condition that the wqe must be signalled in order to schedule the
> completer tasklet which is the simplest fix for this deadlock and is
> fairly low cost. This is the analog for local operations of always
> setting the ackreq bit in all last or only request packets even if the
> operation is not signalled.
>
> Reported-by: Jenny Hack <jhack@xxxxxxx>
> Fixes: c1a411268a4b1 ("RDMA/rxe: Move local ops to subroutine")
> Signed-off-by: Bob Pearson <rpearsonhpe@xxxxxxxxx>
> ---
> drivers/infiniband/sw/rxe/rxe_req.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
Applied to for-next, thanks
Jason
