Re: [linus:master] [connector] c46bfba133: stress-ng.netlink-proc.ops_per_sec -97.2% regression

From: Yin, Fengwei
Date: Fri Jan 12 2024 - 06:28:42 EST




On 1/11/2024 11:19 PM, kernel test robot wrote:


Hello,

we reviewed this report and Fengwei (Cced) pointed out it could be the patch
breaks functionality, then causes stress-ng netlink-proc performance drops
dramatically.

Just FYI. Here is what I observed when running
stress-ng.netlink-proc testing:

Whatever with/without the patch, cn_netlink_send_mult() returns
-ESRCH in most case.

The following is what the cn_netlink_send_mult() returns when
stress-ng.netlink-proc is running:

..
213801 213801 stress-ng-3 cn_netlink_send_mult -3
213801 213801 stress-ng-spawn cn_netlink_send_mult -3
213801 213801 stress-ng-spawn cn_netlink_send_mult -3
213801 213801 stress-ng-wait cn_netlink_send_mult -3
213802 213802 stress-ng-4 cn_netlink_send_mult -3
213802 213802 stress-ng-spawn cn_netlink_send_mult -3
213802 213802 stress-ng-spawn cn_netlink_send_mult -3
213802 213802 stress-ng-wait cn_netlink_send_mult -3
213803 213803 stress-ng-5 cn_netlink_send_mult -3
213803 213803 stress-ng-dead cn_netlink_send_mult -3
213803 213803 stress-ng-dead cn_netlink_send_mult -3
213802 213802 stress-ng-wait cn_netlink_send_mult -3
213801 213801 stress-ng-wait cn_netlink_send_mult -3
213800 213800 stress-ng-wait cn_netlink_send_mult -3
213799 213799 stress-ng-wait cn_netlink_send_mult -3
213798 213798 stress-ng-wait cn_netlink_send_mult -3
154697 154697 stress-ng cn_netlink_send_mult -3
..


Looks like it's not accurate to reset proc_event_num_listeners
according to cn_netlink_send_mult() return value -3.


Regards
Yin, Fengwei