Re: [RFC PATCH 1/6] proc: Reduce cache miss in {snmp,netstat}_seq_show

From: hejianet
Date: Tue Aug 30 2016 - 04:15:39 EST


Hi Eric


On 8/30/16 12:41 AM, Eric Dumazet wrote:
On Tue, 2016-08-30 at 00:03 +0800, Jia He wrote:
This patch exchanges the two loop for collecting the percpu statistics
data. This can aggregate the data by going through all the items of each
cpu sequentially. In snmp_seq_show, just use one buff copy to dislay the
Udp and UdpLite data because they are the same.
This is obviously not true.

On my laptop it seems it handled no UdpLite frames, but got plenty of
Udp ones.

$ grep Udp /proc/net/snmp
Udp: InDatagrams NoPorts InErrors OutDatagrams RcvbufErrors SndbufErrors InCsumErrors
Udp: 1555889 108318 0 3740780 0 0 0
UdpLite: InDatagrams NoPorts InErrors OutDatagrams RcvbufErrors SndbufErrors InCsumErrors
UdpLite: 0 0 0 0 0 0 0
Thanks, you are right. I misunderstand the comments of source codes.
Will resend it

B.R.
Jia



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