On Wed 18-11-15 16:48:22, Johannes Weiner wrote: [...] > So I ran perf record -g -a netperf -t TCP_STREAM multiple times inside > a memory-controlled cgroup, but mostly mem_cgroup_charge_skmem() does > not show up in the profile at all. Once it was there with 0.00%. OK, this sounds very good! This means that most workloads which are not focusing solely on the network traffic shouldn't even notice. I can imagine that workloads with high throughput demands would notice but I would also expect them to disable the feature. Could you add this information to the changelog, please? > I ran another test that downloads the latest kernel image from > kernel.org at 13MB/s (on my i5 laptop) and it looks like this: > > 0.02% 0.01% irq/44-iwlwifi [kernel.kallsyms] [k] mem_cgroup_charge_skmem > | > ---mem_cgroup_charge_skmem > __sk_mem_schedule > tcp_try_rmem_schedule > tcp_data_queue > tcp_rcv_established > tcp_v4_do_rcv > tcp_v4_rcv > ip_local_deliver > ip_rcv > __netif_receive_skb_core > __netif_receive_skb > netif_receive_skb_internal > napi_gro_complete > > The runs vary too much for this to be measurable in elapsed time. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>