issue: Don't update CQ consumer index

[pasis]

Description

We always create CQs that cannot overflow. Therefore, we can use flag IBV_CREATE_CQ_ATTR_IGNORE_OVERRUN and avoid updating dbrec. HW will ignore the consumer index and this will save a memory barrier per successful polling.

What

Don't update CQ consumer index. Create CQs with IBV_CREATE_CQ_ATTR_IGNORE_OVERRUN flag.

Why ?

Performance optimization.

Change type

What kind of change does this PR introduce?

• [ ] Bugfix
• [x] Feature
• [ ] Code style update
• [ ] Refactoring (no functional changes, no api changes)
• [ ] Build related changes
• [ ] CI related changes
• [ ] Documentation content changes
• [ ] Tests
• [ ] Other

Check list

• [ ] Code follows the style de facto guidelines of this project
• [ ] Comments have been inserted in hard to understand places
• [ ] Documentation has been updated (if necessary)
• [ ] Test has been added (if possible)