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From: Leon Romanovsky <leon@kernel.org>
To: Bob Pearson <rpearsonhpe@gmail.com>
Cc: jgg@nvidia.com, zyjzyj2000@gmail.com, linux-rdma@vger.kernel.org
Subject: Re: [PATCH for-next 0/6] RDMA/rxe: Fix potential races
Date: Tue, 19 Oct 2021 16:07:38 +0300	[thread overview]
Message-ID: <YW7DGrG04eJwbf7d@unreal> (raw)
In-Reply-To: <bfb21e28-2f92-e372-871e-32c5f72338f4@gmail.com>

On Tue, Oct 12, 2021 at 03:19:46PM -0500, Bob Pearson wrote:
> On 10/12/21 1:34 AM, Leon Romanovsky wrote:
> > On Sun, Oct 10, 2021 at 06:59:25PM -0500, Bob Pearson wrote:
> >> There are possible race conditions related to attempting to access
> >> rxe pool objects at the same time as the pools or elements are being
> >> freed. This series of patches addresses these races.
> > 
> > Can we get rid of this pool?
> > 
> > Thanks
> > 
> >>
> >> Bob Pearson (6):
> >>   RDMA/rxe: Make rxe_alloc() take pool lock
> >>   RDMA/rxe: Copy setup parameters into rxe_pool
> >>   RDMA/rxe: Save object pointer in pool element
> >>   RDMA/rxe: Combine rxe_add_index with rxe_alloc
> >>   RDMA/rxe: Combine rxe_add_key with rxe_alloc
> >>   RDMA/rxe: Fix potential race condition in rxe_pool
> >>
> >>  drivers/infiniband/sw/rxe/rxe_mcast.c |   5 +-
> >>  drivers/infiniband/sw/rxe/rxe_mr.c    |   1 -
> >>  drivers/infiniband/sw/rxe/rxe_mw.c    |   5 +-
> >>  drivers/infiniband/sw/rxe/rxe_pool.c  | 235 +++++++++++++-------------
> >>  drivers/infiniband/sw/rxe/rxe_pool.h  |  67 +++-----
> >>  drivers/infiniband/sw/rxe/rxe_verbs.c |  10 --
> >>  6 files changed, 140 insertions(+), 183 deletions(-)
> >>
> >> -- 
> >> 2.30.2
> >>
> 
> Not sure which 'this' you mean? This set of patches is motivated by someone at HPE
> running into seg faults caused very infrequently by rdma packets causing seg faults
> when trying to copy data to or from an MR. This can only happen (other than just dumb
> bug which doesn't seem to be the case) by a late packet arriving after the MR is
> de-registered. The root cause of that is the way rxe currently defers cleaning up
> objects with krefs and potential races between cleanup and new packets looking up
> rkeys. I found a lot of potential race conditions and tried to close them off. There
> are another couple of patches coming as well.

I have no doubts that this series fixes RXE, but my request was more general.
Is there way/path to remove everything declared in rxe_pool.c|h?

Thanks

  reply	other threads:[~2021-10-19 13:07 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-10 23:59 [PATCH for-next 0/6] RDMA/rxe: Fix potential races Bob Pearson
2021-10-10 23:59 ` [PATCH for-next 1/6] RDMA/rxe: Make rxe_alloc() take pool lock Bob Pearson
2021-10-20 23:16   ` Jason Gunthorpe
2021-10-21 17:46     ` Bob Pearson
2021-10-25 12:43       ` Jason Gunthorpe
2021-10-25 18:48         ` Robert Pearson
2021-10-10 23:59 ` [PATCH for-next 2/6] RDMA/rxe: Copy setup parameters into rxe_pool Bob Pearson
2021-10-10 23:59 ` [PATCH for-next 3/6] RDMA/rxe: Save object pointer in pool element Bob Pearson
2021-10-20 23:20   ` Jason Gunthorpe
2021-10-21 17:21     ` Bob Pearson
2021-10-25 15:40       ` Jason Gunthorpe
2021-10-10 23:59 ` [PATCH for-next 4/6] RDMA/rxe: Combine rxe_add_index with rxe_alloc Bob Pearson
2021-10-10 23:59 ` [PATCH for-next 5/6] RDMA/rxe: Combine rxe_add_key " Bob Pearson
2021-10-10 23:59 ` [PATCH for-next 6/6] RDMA/rxe: Fix potential race condition in rxe_pool Bob Pearson
2021-10-20 23:23   ` Jason Gunthorpe
2021-10-12  6:34 ` [PATCH for-next 0/6] RDMA/rxe: Fix potential races Leon Romanovsky
2021-10-12 20:19   ` Bob Pearson
2021-10-19 13:07     ` Leon Romanovsky [this message]
2021-10-19 16:35       ` Bob Pearson
2021-10-19 18:43         ` Jason Gunthorpe
2021-10-19 22:51           ` Bob Pearson

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