From: David Miller <davem@davemloft.net>
To: yanjun.zhu@oracle.com
Cc: eric.dumazet@gmail.com, netdev@vger.kernel.org
Subject: Re: [PATCHv3 1/1] forcedeth: use per cpu to collect xmit/recv statistics
Date: Fri, 06 Sep 2019 15:07:15 +0200 (CEST) [thread overview]
Message-ID: <20190906.150715.1583606913988184408.davem@davemloft.net> (raw)
In-Reply-To: <1567674942-5132-2-git-send-email-yanjun.zhu@oracle.com>
From: Zhu Yanjun <yanjun.zhu@oracle.com>
Date: Thu, 5 Sep 2019 05:15:42 -0400
> When testing with a background iperf pushing 1Gbit/sec traffic and running
> both ifconfig and netstat to collect statistics, some deadlocks occurred.
>
> Ifconfig and netstat will call nv_get_stats64 to get software xmit/recv
> statistics. In the commit f5d827aece36 ("forcedeth: implement
> ndo_get_stats64() API"), the normal tx/rx variables is to collect tx/rx
> statistics. The fix is to replace normal tx/rx variables with per
> cpu 64-bit variable to collect xmit/recv statistics. The per cpu variable
> will avoid deadlocks and provide fast efficient statistics updates.
>
> In nv_probe, the per cpu variable is initialized. In nv_remove, this
> per cpu variable is freed.
>
> In xmit/recv process, this per cpu variable will be updated.
>
> In nv_get_stats64, this per cpu variable on each cpu is added up. Then
> the driver can get xmit/recv packets statistics.
>
> A test runs for several days with this commit, the deadlocks disappear
> and the performance is better.
>
> Tested:
...
> Fixes: f5d827aece36 ("forcedeth: implement ndo_get_stats64() API")
> CC: Joe Jin <joe.jin@oracle.com>
> CC: JUNXIAO_BI <junxiao.bi@oracle.com>
> Reported-and-tested-by: Nan san <nan.1986san@gmail.com>
> Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Applied.
prev parent reply other threads:[~2019-09-06 13:07 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-05 9:15 [PATCHv3 0/1] Fix deadlock problem and make performance better Zhu Yanjun
2019-09-05 9:15 ` [PATCHv3 1/1] forcedeth: use per cpu to collect xmit/recv statistics Zhu Yanjun
2019-09-06 13:07 ` David Miller [this message]
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