From: Luke Gorrie <luke-vEt0keKvJLw@public.gmane.org>
To: Linhaifeng <haifeng.lin-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
Cc: "dev-VfR2kkLFssw@public.gmane.org"
<dev-VfR2kkLFssw@public.gmane.org>,
"Michael S. Tsirkin"
<mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH] vhost: flush used->idx update before reading avail->flags
Date: Fri, 24 Apr 2015 09:27:19 +0200 [thread overview]
Message-ID: <CAA2XHbef=TBAoAwNaAuVOAtHBqiQg2rD1-ExAYkHJ4pLsozJ3Q@mail.gmail.com> (raw)
In-Reply-To: <553995DB.4000801-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
On 24 April 2015 at 03:01, Linhaifeng <haifeng.lin-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> wrote:
> If not add memory fence what would happen? Packets loss or interrupt
> loss?How to test it ?
>
You should be able to test it like this:
1. Boot two Linux kernel (e.g. 3.13) guests.
2. Connect them via vhost switch.
3. Run continuous traffic between them (e.g. iperf).
I would expect that within a reasonable timeframe (< 1 hour) one of the
guests' network interfaces will hang indefinitely due to a missed interrupt.
You won't be able to reproduce this using DPDK guests because they are not
using the same interrupt suppression method.
This is a serious real-world problem. I wouldn't deploy the vhost
implementation without this fix.
Cheers,
-Luke
next prev parent reply other threads:[~2015-04-24 7:27 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-22 16:33 [PATCH] vhost: flush used->idx update before reading avail->flags Huawei Xie
[not found] ` <1429720392-25345-1-git-send-email-huawei.xie-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2015-04-23 13:57 ` Luke Gorrie
2015-04-24 1:01 ` Linhaifeng
[not found] ` <553995DB.4000801-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2015-04-24 2:40 ` Xie, Huawei
2015-04-24 7:27 ` Luke Gorrie [this message]
2015-06-09 7:04 ` Linhaifeng
2015-06-09 7:45 ` Luke Gorrie
2015-06-09 8:46 ` Michael S. Tsirkin
2015-06-09 13:34 ` Xie, Huawei
2015-06-10 2:36 ` Linhaifeng
2015-06-10 8:30 ` Luke Gorrie
2015-06-11 0:50 ` Linhaifeng
2015-04-29 11:11 ` [PATCH v2] " Huawei Xie
2015-05-13 10:46 ` Thomas Monjalon
2015-05-15 13:43 ` Nikita Kalyazin
2015-05-15 15:23 ` Michael S. Tsirkin
2015-05-18 6:18 ` Nikita Kalyazin
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