[LU-7218] Client fails to obtain grant: ofd_grant()) fs2test-OST0003: client xxx requesting > 2GB grant 2147483648

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.8.0
• Affects Version/s: Lustre 2.5.3
• Labels: patch
• Severity: 3
• Assignee: Gregoire Pichon
• Reporter: Gregoire Pichon

Description

The problem has been detected on Lustre 2.5.3.90.

The application running on the client is failing msync() operation with a SIGBUS signal. Additionally, read/write Posix IO performance is quite low.

The issue comes from an invalid setting of max_dirty_mb tunable value to 2048. After some time the client consumes all its grants and the OSS log the following error message.

1441296045 2015 Sep 3 18:00:45 valx7 kern err kernel LustreError: 16623:0:(ofd_grant.c:607:ofd_grant()) fs2test-OST0003: client fa81e2f5-d6fc-f980-5a79-f76c8a08cec8/ffff880629792c00 requesting > 2GB grant 2147483648

Indeed the max_dirty_mb value should only be set to a value strictly lower than 2GB.

I will post a patch that fixes osc_max_dirty_mb_seq_write() routine to prevent setting the value to 2048.

Comments

[Joseph Gmitter (Inactive)]

Landed for 2.8.0

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch http://review.whamcloud.com/16652/
Subject: LU-7218 osc: fix max_dirty_mb tunable setting limit
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: a459beefbbc82aadaae08debef6467ccef626aea

[Gerrit Updater]

Grégoire Pichon ([e-mail]) uploaded a new patch: http://review.whamcloud.com/16652
Subject: LU-7218 osc: fix max_dirty_mb tunable setting limit
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 56a0ddd3c4a4527c4a21c13dc24cb0cb5a03e7c4