Roopa Prabhu d297653dd6 rtnetlink: fdb dump: optimize by saving last interface markers ... fdb dumps spanning multiple skb's currently restart from the first interface again for every skb. This results in unnecessary iterations on the already visited interfaces and their fdb entries. In large scale setups, we have seen this to slow down fdb dumps considerably. On a system with 30k macs we see fdb dumps spanning across more than 300 skbs. To fix the problem, this patch replaces the existing single fdb marker with three markers: netdev hash entries, netdevs and fdb index to continue where we left off instead of restarting from the first netdev. This is consistent with link dumps. In the process of fixing the performance issue, this patch also re-implements fix done by commit 472681d57a ("net: ndo_fdb_dump should report -EMSGSIZE to rtnl_fdb_dump") (with an internal fix from Wilson Kok) in the following ways: - change ndo_fdb_dump handlers to return error code instead of the last fdb index - use cb->args strictly for dump frag markers and not error codes. This is consistent with other dump functions. Below results were taken on a system with 1000 netdevs and 35085 fdb entries: before patch: $time bridge fdb show | wc -l 15065 real 1m11.791s user 0m0.070s sys 1m8.395s (existing code does not return all macs) after patch: $time bridge fdb show | wc -l 35085 real 0m2.017s user 0m0.113s sys 0m1.942s Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: Wilson Kok <wkok@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2016-09-01 16:56:15 -07:00
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Kconfig	net: switchdev: Drop EXPERIMENTAL from description	2016-05-14 17:06:37 -04:00
Makefile
switchdev.c	rtnetlink: fdb dump: optimize by saving last interface markers	2016-09-01 16:56:15 -07:00