[LU-9565] lnet-selftest: Newly added "off" parameter no longer working

• Type: Bug
• Resolution: Unresolved
• Priority: Minor
• Severity: 3
• Assignee: Amir Shehata (Inactive)
• Reporter: Doug Oucharek (Inactive)

Description

While working on LU-9500, I needed to create a message stream where the first fragment in the scatter/gather lists do not start page aligned.  This can be done via lnet-selftest by using a new parameter, "off", which was added in patch: https://review.whamcloud.com/#/c/12496/.  This is no working anymore.

The lnet-selftest code itself seems to be erring on the parameter.

Issue Links

• is blocking: LU-9500 MOFED 4/mlx5: Aligning non-aligned page addresses trigger dump_cqe

Comments

[Doug Oucharek (Inactive)]

Looks like this problem has been there since the beginning of this new parameter.  When you use a bulk size of 1M and apply an offset (i.e. "off=64), the system will need 257 fragments which is greater than the max allowed of 256.  

The workaround is to use a smaller size (i.e. "size=512K").  It would be good if lnet-selftest allows for 257 fragments as the max to accommodate the offset parameter.

I'm leaving this ticket open to do just that, but lowering the priority to minor.