[LU-14639] confusion of lru_size=0 if lru-resize disabled

• Type: Bug
• Resolution: Unresolved
• Priority: Minor
• Affects Version/s: Lustre 2.15.0
• Environment: master(commit:gdfe87b0)
• Severity: 3
• Assignee: WC Triage
• Reporter: Shuichi Ihara

Description

There is an configure option to enable/disable lru-resize (--enable-lru-resize/
--disable-lru-resize), but that confuses when lru_size set 0.
In both cases, it's able to set 0 to lru_size, but they make different behaviors.

And currently, if lru-resize disabled(--disable-lru-resize) when lustre builds, it won't be able to re-enable lru-resize even lru_size set 0.

./configure --enable-lru-resize

[root@sky06 ~]# mount -t lustre 10.0.11.110@o2ib10:/ai7990 /ai7990
mount -t lustre 10.0.11.110@o2ib10:/ai7990 /ai7990
mount.lustre: according to /etc/mtab 10.0.11.110@o2ib10:/ai7990 is already mounted on /ai7990
[root@sky06 ~]# lctl get_param ldlm.*.*.lru_size
[e-mail]_size=8800
ldlm.namespaces.ai7990-MDT0000-mdc-ffff8f5408893800.lru_size=1
ldlm.namespaces.ai7990-MDT0001-mdc-ffff8f5408893800.lru_size=0
ldlm.namespaces.ai7990-OST0000-osc-ffff8f5408893800.lru_size=0
ldlm.namespaces.ai7990-OST0001-osc-ffff8f5408893800.lru_size=0
[root@sky06 ~]# lctl set_param ldlm.*.*.lru_size=0
[e-mail]_size=0
ldlm.namespaces.ai7990-MDT0000-mdc-ffff8f5408893800.lru_size=0
ldlm.namespaces.ai7990-MDT0001-mdc-ffff8f5408893800.lru_size=0
ldlm.namespaces.ai7990-OST0000-osc-ffff8f5408893800.lru_size=0
ldlm.namespaces.ai7990-OST0001-osc-ffff8f5408893800.lru_size=0
[root@sky06 ~]# time find /ai7990/testdir > /dev/null 2>&1

real	0m15.183s
user	0m0.367s
sys	0m6.587s
[root@sky06 ~]# lctl get_param ldlm.*.*.lru_size
[e-mail]_size=0
ldlm.namespaces.ai7990-MDT0000-mdc-ffff8f5408893800.lru_size=30502
ldlm.namespaces.ai7990-MDT0001-mdc-ffff8f5408893800.lru_size=0
ldlm.namespaces.ai7990-OST0000-osc-ffff8f5408893800.lru_size=2499
ldlm.namespaces.ai7990-OST0001-osc-ffff8f5408893800.lru_size=2501

./configure --disable-lru-resize

[root@sky06 ~]# mount -t lustre 10.0.11.110@o2ib10:/ai7990 /ai7990
[root@sky06 ~]# lctl get_param ldlm.*.*.lru_size
[e-mail]_size=8800
ldlm.namespaces.ai7990-MDT0000-mdc-ffff8ef7ae5ef000.lru_size=8800
ldlm.namespaces.ai7990-MDT0001-mdc-ffff8ef7ae5ef000.lru_size=8800
ldlm.namespaces.ai7990-OST0000-osc-ffff8ef7ae5ef000.lru_size=8800
ldlm.namespaces.ai7990-OST0001-osc-ffff8ef7ae5ef000.lru_size=8800
[root@sky06 ~]# lctl set_param ldlm.*.*.lru_size=0
[e-mail]_size=0
ldlm.namespaces.ai7990-MDT0000-mdc-ffff8ef7ae5ef000.lru_size=0
ldlm.namespaces.ai7990-MDT0001-mdc-ffff8ef7ae5ef000.lru_size=0
ldlm.namespaces.ai7990-OST0000-osc-ffff8ef7ae5ef000.lru_size=0
ldlm.namespaces.ai7990-OST0001-osc-ffff8ef7ae5ef000.lru_size=0
[root@sky06 ~]# time find /ai7990/testdir > /dev/null 2>&1
 
real	0m26.491s
user	0m0.358s
sys	0m11.809s
[root@sky06 ~]# lctl get_param ldlm.*.*.lru_size
[e-mail]_size=0
ldlm.namespaces.ai7990-MDT0000-mdc-ffff8ef7ae5ef000.lru_size=0
ldlm.namespaces.ai7990-MDT0001-mdc-ffff8ef7ae5ef000.lru_size=0
ldlm.namespaces.ai7990-OST0000-osc-ffff8ef7ae5ef000.lru_size=0
ldlm.namespaces.ai7990-OST0001-osc-ffff8ef7ae5ef000.lru_size=0

Issue Links

• is related to: LU-11077 Client-specific tunable parameter configuration