[LU-14641] per extents bytes allocation stats

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.15.0
• Assignee: Wang Shilong (Inactive)
• Reporter: Wang Shilong (Inactive)

Description

Seeing debug messages on the console during large RPC writes:

Apr  3 01:29:08 foss01 kernel: Lustre: 12536:0:(osd_handler.c:1947:osd_trans_start()) work-OST0004: credits 24347 > trans_max 12800
Apr  3 01:29:08 foss01 kernel: Lustre: 12536:0:(osd_handler.c:1876:osd_trans_dump_creds())   create: 0/0/0, destroy: 0/0/0
Apr  3 01:29:08 foss01 kernel: Lustre: 12536:0:(osd_handler.c:1883:osd_trans_dump_creds())   attr_set: 1/1/0, xattr_set: 2/15/0
Apr  3 01:29:08 foss01 kernel: Lustre: 12536:0:(osd_handler.c:1893:osd_trans_dump_creds())   write: 2/24182/0, punch: 0/0/0, quota 5/149/0
Apr  3 01:29:08 foss01 kernel: Lustre: 12536:0:(osd_handler.c:1900:osd_trans_dump_creds())   insert: 0/0/0, delete: 0/0/0
Apr  3 01:29:08 foss01 kernel: Lustre: 12536:0:(osd_handler.c:1907:osd_trans_dump_creds())   ref_add: 0/0/0, ref_del: 0/0/0

These are likely caused by patches from LU-14134 landing that changed the way transaction sizes are calculated (in theory reducing transaction size, but not always).

We might need an interface to check how extent per bytes going with system filled up, and also debug message to check how many credits calculated in  osd_declare_write_commit()

Issue Links

• is related to: LU-14134 reduce credits for new writing potentially