Re: [PATCH for-next v7 0/7] On-Demand Paging on SoftRoCE

[Zhu Yanjun]

在 2023/12/7 14:37, Daisuke Matsuda (Fujitsu) 写道:
> On Tue, Dec 5, 2023 10:51 AM Zhu Yanjun wrote:
> > 在 2023/12/5 8:11, Jason Gunthorpe 写道:
> > > On Thu, Nov 09, 2023 at 02:44:45PM +0900, Daisuke Matsuda wrote:
> > > > Daisuke Matsuda (7):
> > > >     RDMA/rxe: Always defer tasks on responder and completer to workqueue
> > > >     RDMA/rxe: Make MR functions accessible from other rxe source code
> > > >     RDMA/rxe: Move resp_states definition to rxe_verbs.h
> > > >     RDMA/rxe: Add page invalidation support
> > > >     RDMA/rxe: Allow registering MRs for On-Demand Paging
> > > >     RDMA/rxe: Add support for Send/Recv/Write/Read with ODP
> > > >     RDMA/rxe: Add support for the traditional Atomic operations with ODP
> > >
> > > What is the current situation with rxe? I don't recall seeing the bugs
> > > that were reported get fixed?
>
> Well, I suppose Jason is mentioning "blktests srp/002 hang".
> cf. https://lore.kernel.org/linux-rdma/dsg6rd66tyiei32zaxs6ddv5ebefr5vtxjwz6d2ewqrcwisogl@ge7jzan7dg5u/T/
>
> It is likely to be a timing issue. Bob reported that "siw hangs with the debug kernel",
> so the hang looks not specific to rxe.
> cf. https://lore.kernel.org/all/53ede78a-f73d-44cd-a555-f8ff36bd9c55@xxxxxxx/T/
> I think we need to decide whether to continue to block patches to rxe since nobody has successfully fixed the issue.
>
>
> There is another issue that causes kernel panic.
> [bug report][bisected] rdma_rxe: blktests srp lead kernel panic with 64k page size
> cf. https://lore.kernel.org/all/CAHj4cs9XRqE25jyVw9rj9YugffLn5+f=1znaBEnu1usLOciD+g@xxxxxxxxxxxxxx/T/
>
> https://patchwork.kernel.org/project/linux-rdma/list/?series=798592&state=*
> Zhijian has submitted patches to fix this, and he got some comments.
> It looks he is involved in CXL driver intensively these days.
> I guess he is still working on it.
>
> > Exactly. A problem is reported in the link
> > https://www.spinics.net/lists/linux-rdma/msg120947.html
> >
> > It seems that a variable 'entry' set but not used
> > [-Wunused-but-set-variable]
>
> Yeah, I can revise the patch anytime.
>
> > And ODP is an important feature. Should we suggest to add a test case
> > about this ODP in rdma-core to verify this ODP feature?
>
> Rxe can share the same tests with mlx5.
> I added test cases for Write, Read and Atomic operations with ODP,
> and we can add more tests if there are any suggestions.
> Cf. https://github.com/linux-rdma/rdma-core/blob/master/tests/test_odp.py

Thanks a lot.
Do you make tests with blktests after your patches are applied with the 
latest kernel?

Zhu Yanjun

> Thanks,
> Daisuke Matsuda
>
> > Zhu Yanjun
> >
> > > I'm reluctant to dig a deeper hold until it is done?
> > >
> > > Thanks,
> > > Jason