Re: [PATCH net] rds: Fix incorrect statistics counting

From: Santosh Shilimkar
Date: Wed Sep 06 2017 - 12:21:04 EST


On 9/6/2017 9:12 AM, HÃkon Bugge wrote:

[...]


Hi Santosh,


Yes, I agree with accuracy of s_send_lock_queue_raced. But the main point is that the existing code counts some partial share of when it is _not_ raced.

So, in the critical path, my patch adds one test_bit(), which hits the local CPU cache, if not raced. If raced, some other thread is in control, so I would not think the added cycles would make any big difference.

Cycles added for no good reason is the point.

I can send a v2 where the race tightening is removed if you like.

Yes please.

Regards,
Santosh