Messages in this thread | | | From | Yafang Shao <> | Date | Thu, 26 Jul 2018 09:42:50 +0800 | Subject | Re: [PATCH net-next] tcp: add SNMP counter for the number of packets pruned from ofo queue |
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On Wed, Jul 25, 2018 at 9:59 PM, Yafang Shao <laoar.shao@gmail.com> wrote: > On Wed, Jul 25, 2018 at 9:55 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote: >> >> >> On 07/25/2018 06:40 AM, Yafang Shao wrote: >> >>> >>> Because we want to know why packets were dropped. >>> If that could be show in netstat, we could easily find that it is >>> dropped due to ofo prune. >> >> >> We have a counter already for these events : LINUX_MIB_OFOPRUNED >> >> You want to add another counter tracking number of _skbs_, >> which has no precise value for user, >> given each skb can contain a variable number of _packets_. >> > > Got it. > > But with LINUX_MIB_OFOPRUNED, we only know tcp_prune_ofo_queue is > called, but have no idea how many skbs are dropped. >
Hi Eric,
LINUX_MIB_TCPOFOQUEUE, LINUX_MIB_TCPOFODROP and LINUX_MIB_TCPOFOMERGE are all for the number of SKBs, but only LINUX_MIB_OFOPRUNED is for the event, that could lead misunderstading. So I think introducing a counter for the number of SKB pruned could be better, that could help us to track the whole behavior of ofo queue. That is why I submit this patch.
Thanks Yafang
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