[LUDOC-40] Create Documentation for multi-threaded ptlrpcd

• Type: New Feature
• Resolution: Fixed
• Priority: Major
• Labels: releases
• Assignee: Cliff White (Inactive)
• Reporter: Bryon Neitzel (Inactive)

Description

Please write the documentation necessary for multithreaded ptlrpcd to be understood and used in Lustre 2.2. Please include any tunables that affect this feature. Only the raw content needs to be written - any grammar checking, spell checking, formatting, etc. will be done by a doc writer. The content can be appended to this ticket.

Comments

[Cliff White (Inactive)]

I would appreciate a response at your earliest convience.
--------
New question - what is the parameter name for the ptlrpcd_load_policy? This
is not in the document.
is it "ptlrpcd_load_policy=XX" ??
---------

--------

For the max_ptlrpcds parameter:

• The absolute minimum is 2 per node, regardless of number of cores?
• The default is one thread per core, including hyperthreading?
• Is there any limit or maximum in the code?

• You mention large directory traversal and statahead as operations that
  are async RPC-intensive,
  are there any other situations a user may need to be aware of?

Somewhat outside question:

• Is there any tuning of RPC behavior in this area, in other words for a
  specific type
  of RPC or action, can a user force async or sync behavior?

–
cliffw
Support Guy
WhamCloud, Inc.
www.whamcloud.com

[Cliff White (Inactive)]

Asked these in email, putting in bug for record, or in case anybody else wants to answer them here.
--------

For the max_ptlrpcds parameter:

• The absolute minimum is 2 per node, regardless of number of cores?
• The default is one thread per core, including hyperthreading?
• Is there any limit or maximum in the code?

• You mention large directory traversal and statahead as operations that are async RPC-intensive,
  are there any other situations a user may need to be aware of?

Somewhat outside question:

• Is there any tuning of RPC behavior in this area, in other words for a specific type
  of RPC or action, can a user force async or sync behavior?

[Peter Jones]

Hi Cliff

Please can you integrate this material into the manual

Thanks

Peter

[Peter Jones]

Thanks for getting this content created FanYong but we should keep the ticket open until it has actually landed in the manual. We'll get this reassigned now.

[nasf (Inactive)]

Document is done.

[nasf (Inactive)]

Draft for multi-threaded ptlrpcd, it should be part of Lustre manual.

[Andreas Dilger]

This should indicate that multiple OI files is a new feature in Lustre 2.2 and that filesystems formatted with Lustre 2.2 cannot be downgraded to an earlier version of Lustre (this is always true, but it doesn't hurt to state it again).