On Wed, Aug 27, 2008 at 09:49:10AM -0700, Rick Jones wrote:Andi Kleen wrote:I'm guessing you mean increase their latency? I agree, it could - depends entirely on the PPS in production I suspect.Those banks really want to crank down on latency - to the point they start disabling interrupt coalescing. I bet they'd toss anything out they could to shave another microsecond.
This change would actually likely lower their latency.
No, moving the time stamps into the socket decreases latency
for all packets that don't need time stamps. And they likely have some packets which don't need time stamps too.
As a secondary effect if they use a RT kernel it might
be also beneficial to do the (depending on the platform)
costly time stamp in the lower priority socket context
than in the high priority interrupt thread.