[LU-13503] allow setting larger max_mod_rpcs_in_flight dynamically

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.14.0, Lustre 2.12.6
• Assignee: Jian Yu
• Reporter: Andreas Dilger

Description

Currently, an error is reported if mdc.*.max_mod_rpcs_in_flight is set larger or equal to mdc.*.max_rpcs_in_flight. However, it makes more sense to allow the user to set max_mod_rpcs_in_flight directly, and just increase max_rpcs_in_flight appropriately, rather than returning an error and telling the user to do that instead.

Also, during mount config parameter processing, there may be a race between MDC setup and config log handling, so allow max_mod_rpcs_in_flight to be temporarily increased, and then it will be reduced later to the server value when the OCD information is handled.

Issue Links

• is related to: LU-14145 protect cli->cl_import with with_imp_locked()
• is related to: LU-16454 can't set max_mod_rpcs_in_flight > 8
• is related to: LU-14144 get and set Lustre module parameters via "lctl get_param/set_param"

Comments

[Jian Yu]

The issue in this ticket was resolved. The remaining two separate issues are tracked in LU-14144 and LU-14145.

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/38893/
Subject: LU-13503 mdc: allow setting max_mod_rpcs_in_flight larger
Project: fs/lustre-release
Branch: b2_12
Current Patch Set:
Commit: ef8b218c99f69bc8f2aa632c3c5c457d73b01854

[Jian Yu]

There are two more patches needed for this ticket.

[Gerrit Updater]

Jian Yu ([e-mail]) uploaded a new patch: https://review.whamcloud.com/38893
Subject: LU-13503 mdc: allow setting max_mod_rpcs_in_flight larger
Project: fs/lustre-release
Branch: b2_12
Current Patch Set: 1
Commit: 32efe830b5952130ff2eee26659e3c92a120c9a9

[Peter Jones]

Landed for 2.14

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/38455/
Subject: LU-13503 mdc: allow setting max_mod_rpcs_in_flight larger
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 6d314902e6d19229379577aab60d4b20a5b4d2ea

[James A Simmons]

Note this sysfs file has issues with import locking. That should be fixed in another patch.

[Andreas Dilger]

A separate patch is needed to allow using "lctl set_param [-P] mdt.*.max_mod_rpcs_in_flight=N" via the normal Lustre parameter interface. It doesn't make sense that this is only available as a module parameter.

[Gerrit Updater]

Andreas Dilger ([e-mail]) uploaded a new patch: https://review.whamcloud.com/38455
Subject: LU-13503 mdc: allow setting max_mod_rpcs_in_flight larger
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: d5dd5b436b52885527db10a72243da5968536b16