This continues bz#509585 regarding with Broadcom 10G firmware granularity.
Theoretically, it seems possible to increase the granularity to 4us instead
of 12us, but according with Broadcom this is a delicate change that might
cause some unexpected side effects.
Hi Eilon, Vladislav.
Could you guys give us a status update on this?
My apologies for the late response - I was on vacation.
I can provide a patch to set the granularity to 4us instead of 12, but internal testing did not show any improvement. This was expected due to FW mechanism that sends the first interrupt as soon as it is received and only then enforces the required minimal time before issuing the second interrupt. So if a packet was received after more than 12us (or 48 as it is configured by default) it will cause an interrupt to be issued immediately - decreasing the minimal timeout to 4us did not actually improve anything.
I will post this patch anyway to Dave Miller's net-next once the merge window will open.
Do you mind to attach the patch here too? I think the merge window isn't
opened yet and we can be testing it on our test system too.
Created attachment 364942 [details]
bnx2x: 4us coalescing granularity
This patch will do the trick
I thought it would require a firmware change too, right?
Can you provide? Or where can we get it?
Actually, this patch is enough. No FW change is required. This change will set the HW timers that the FW is using to 4us instead of 12us so the FW itself does not need to change.
This patch is part of version 1.52.1-5 which is integrated to RH5.5 as part of BZ 515716.
(In reply to comment #12)
> This patch is part of version 1.52.1-5 which is integrated to RH5.5 as part of
> BZ 515716.
Yes. I decide to do not close this bug as duplicate just for additional testing.
You can download this test kernel from http://people.redhat.com/dzickus/el5
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*** Bug 509585 has been marked as a duplicate of this bug. ***
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