On Fri, Jul 11, 2025 at 07:17:29AM -0700, Jakub Kicinski wrote:
On Fri, 11 Jul 2025 02:14:03 +0000 Hangbin Liu wrote:
sleep 5
- # Schedule out for a bit, address GC runs from the power efficient WQ
- # if the long sleep above has put the whole system into sleep state
- # the WQ may have not had a chance to run.
- sleep 0.1
How about use slowwait to check if the address still exists.
Weirdly if we read the addresses twice they disappear, I haven't looked into the code for the why, but seemed like using slowwait could potentially mask the addresses sticking around when nobody runs the Netlink handlers for a while? Dunno..
Not sure if I understand correctly. Do you mean the addresses will keep there if we use slowwait?
Thanks Hangbin
I queued this debug patch a couple of months ago:
sleep 5
- run_cmd_grep_fail "10.23.11." ip addr show dev "$devdummy"
- ip addr show dev "$devdummy" > /tmp/a
- run_cmd_grep_fail "10.23.11." cat /tmp/a if [ $? -eq 0 ]; then
check_err 1end_test "FAIL: preferred_lft addresses remaining"
check_err 1cat /tmp/aecho "==="ip addr show dev "$devdummy"end_test "FAIL: preferred_lft addresses remaining ($lft)"And when it flakes the output looks like this:
# 7.23 [+7.00] 297: test-dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 # 7.23 [+0.00] link/ether 9e:a6:c4:c2:1b:16 brd ff:ff:ff:ff:ff:ff # 7.23 [+0.00] inet 10.23.11.81/32 scope global deprecated dynamic test-dummy0 # 7.23 [+0.00] valid_lft 0sec preferred_lft 0sec # 7.23 [+0.00] inet 10.23.11.84/32 scope global deprecated dynamic test-dummy0 # 7.24 [+0.00] valid_lft 0sec preferred_lft 0sec # 7.24 [+0.00] inet 10.23.11.93/32 scope global deprecated dynamic test-dummy0 # 7.24 [+0.00] valid_lft 0sec preferred_lft 0sec # 7.24 [+0.00] inet 10.23.11.94/32 scope global deprecated dynamic test-dummy0 # 7.24 [+0.00] valid_lft 0sec preferred_lft 0sec # 7.24 [+0.00] inet 10.23.11.97/32 scope global deprecated dynamic test-dummy0 # 7.24 [+0.00] valid_lft 0sec preferred_lft 0sec # 7.24 [+0.00] inet 10.23.11.99/32 scope global deprecated dynamic test-dummy0 # 7.24 [+0.00] valid_lft 0sec preferred_lft 0sec # 7.24 [+0.00] inet6 fe80::9ca6:c4ff:fec2:1b16/64 scope link proto kernel_ll # 7.24 [+0.00] valid_lft forever preferred_lft forever # 7.24 [+0.00] === # 7.25 [+0.00] 297: test-dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 # 7.25 [+0.00] link/ether 9e:a6:c4:c2:1b:16 brd ff:ff:ff:ff:ff:ff # 7.25 [+0.00] inet6 fe80::9ca6:c4ff:fec2:1b16/64 scope link proto kernel_ll # 7.25 [+0.00] valid_lft forever preferred_lft forever # 7.25 [+0.00] FAIL: preferred_lft addresses remaining (1)