Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1569893

Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress and OOM

From Vineeth Remanan Pillai <vineethp@amazon.com>
Newsgroups linux.kernel
Subject Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress and OOM
Date 2017-01-30 18:00 +0100
Message-ID <t5nt8-6kA-13@gated-at.bofh.it> (permalink)
References <t1nUK-3Tq-13@gated-at.bofh.it> <t1nUK-3Tq-11@gated-at.bofh.it> <t56Vj-4UH-7@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On 01/29/2017 03:09 PM, Boris Ostrovsky wrote:
>
> There are couple of problems with this patch.
> 1. The 'if' clause now evaluates to true on pretty much every call to 
> xennet_alloc_rx_buffers().
Thanks for catching this. In my testing I did not notice this - mostly 
because of the nature of the workload in my testing.

> 2. It tickles a latent bug during resume where the timer triggers 
> before we re-connect. The trouble is that we now try to dereference 
> queue->rx.sring which is NULL since we disconnect in 
> netfront_resume(). (Curiously, I only observe it with 32-bit guests)
I think we may hit this bug after removing the timer as well. We call 
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY soon after, which also dereference 
queue->rx.sring.

Thanks,
Vineeth

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH v2] xen-netfront: Fix Rx stall during network stress and OOM Vineeth Remanan Pillai <vineethp@amazon.com> - 2017-01-19 17:40 +0100
  Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress  and OOM David Miller <davem@davemloft.net> - 2017-01-19 18:20 +0100
    Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress  and OOM David Miller <davem@davemloft.net> - 2017-01-19 19:20 +0100
    Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress and  OOM Vineeth Remanan Pillai <vineethp@amazon.com> - 2017-01-19 19:30 +0100
  Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress  and OOM David Miller <davem@davemloft.net> - 2017-01-20 20:10 +0100
  Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress and  OOM Boris Ostrovsky <boris.ostrovsky@oracle.com> - 2017-01-30 00:20 +0100
    Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress and  OOM Vineeth Remanan Pillai <vineethp@amazon.com> - 2017-01-30 18:00 +0100
      Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress and  OOM Boris Ostrovsky <boris.ostrovsky@oracle.com> - 2017-01-30 18:10 +0100
        Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress and  OOM Vineeth Remanan Pillai <vineethp@amazon.com> - 2017-01-30 18:20 +0100
      Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress and  OOM Vineeth Remanan Pillai <vineethp@amazon.com> - 2017-01-31 18:00 +0100

csiph-web