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Date:   Tue, 10 Aug 2021 11:22:55 -0500 (CDT)
From:   Timothy Pearson <tpearson@raptorengineering.com>
To:     hedrick <hedrick@rutgers.edu>
Cc:     Chuck Lever <chuck.lever@oracle.com>,
        "J. Bruce Fields" <bfields@fieldses.org>,
        linux-nfs <linux-nfs@vger.kernel.org>
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Subject: Re: CPU stall, eventual host hang with BTRFS + NFS under heavy load
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Thread-Topic: CPU stall, eventual host hang with BTRFS + NFS under heavy load
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To chime in on the client topic, we have a pretty wide mix of kernels in us=
e and haven't really seen any issues aside from some oddities specific to 4=
.14 / 5.3 on armhf (embedded dev systems).  I know 5.13.4 is fine on the cl=
ient side.

----- Original Message -----
> From: "hedrick" <hedrick@rutgers.edu>
> To: "Chuck Lever" <chuck.lever@oracle.com>
> Cc: "Timothy Pearson" <tpearson@raptorengineering.com>, "J. Bruce Fields"=
 <bfields@fieldses.org>, "linux-nfs"
> <linux-nfs@vger.kernel.org>
> Sent: Tuesday, August 10, 2021 10:03:48 AM
> Subject: Re: CPU stall, eventual host hang with BTRFS + NFS under heavy l=
oad

> FYI, we=E2=80=99re reasonably sure 5.8 is OK on the client side. We don=
=E2=80=99t have much
> testing with 5.4, but we=E2=80=99re hoping current patch levels of 5.4 ar=
e as well. So
> we=E2=80=99re not really reporting anything here about the client side. (=
I=E2=80=99ve looked at
> both upstream and Ubuntu kernel source. They=E2=80=99re pretty good about=
 following the
> upstream NFS source.)
>=20
>> On Aug 9, 2021, at 1:37 PM, Chuck Lever III <chuck.lever@oracle.com> wro=
te:
>>=20
>>> We=E2=80=99ve also had a history of issues with 4.2 problems on clients=
. That=E2=80=99s why we
>>> backed off to 4.0 initially. Clients were seeing hangs.
>>=20
> > Let's stick with the server issue for the moment.