MSI. Unlike as with iflib_fast_intr_ctx(), the former will also enqueue
_task_fn_tx() in addition to _task_fn_rx() if appropriate, bringing TCP
TX throughput of EM-class devices on par with the MSI-X case and, thus,
close to wirespeed/pre-iflib(4) times again. [1]
Note that independently of the interrupt type, the UDP performance with
these MACs still is abysmal and nowhere near to where it was before the
conversion of em(4) to iflib(4).
o In iflib_init_locked(), announce which free list failed to set up.
o In _task_fn_tx() when running netmap(4), issue ifdi_intr_enable instead
of the ifdi_tx_queue_intr_enable method in case of a "legacy" interrupt
as the latter is valid with MSI-X only.
o Instead of adding the missing - and apparently convoluted enough that a
DBG_COUNTER_INC was put into a wrong spot in _task_fn_rx() - checks for
ifdi_{r,t}x_queue_intr_enable being available in the MSI-X case also to
iflib_fast_intr_rxtx(), factor these out to iflib_device_register() and
make the checks fail gracefully rather than panic. This avoids invoking
the checks at runtime over and over again in iflib_fast_intr_rxtx() and
_task_fn_{r,t}x() - even if it's just in case of INVARIANTS - and makes
these functions more readable.
o In iflib_rx_structures_setup(), only initialize LRO resources if device
and driver have LRO capability in order to not waste memory. Also, free
the LRO resources again if setting them up fails for one of the queues.
However, don't bother invoking iflib_rx_sds_free() in that case because
iflib_rx_structures_setup() doesn't call iflib_rxsd_alloc() either (and
iflib_{device,pseudo}_register() will issue iflib_rx_sds_free() in case
of failure via iflib_rx_structures_free(), but there definitely is some
asymmetry left to be fixed, though).
o Similarly, free LRO resources again in iflib_rx_structures_free().
o In iflib_irq_set_affinity(), handle get_core_offset() errors gracefully
instead of panicing (but only in case of INVARIANTS). This is a follow-
up to r344132, as such driver bugs shouldn't be fatal.
o Likewise, handle unknown iflib_intr_type_t in iflib_irq_alloc_generic()
gracefully, too.
o Bring yet more sanity to iflib_msix_init():
- If the device doesn't provide enough MSI-X vectors or not all vectors
can be allocate so the expected number of queues in addition to admin
interrupts can't be supported, try MSI next (and then INTx) as proper
MSI-X vector distribution can't be assured in such cases. In essence,
this change brings r254008 forward to iflib(4). Also, this is the fix
alluded to in the commit message of r343934.
- If the MSI-X allocation has failed, don't prematurely announce MSI is
going to be used as the latter in fact may not be available either.
- When falling back to MSI, only release the MSI-X table resource again
if it was allocated in iflib_msix_init(), i. e. isn't supplied by the
driver, in the first place.
o In mp_ndesc_handler(), handle unknown type arguments gracefully, too.
PR: 235031 (likely) [1]
Reviewed by: shurd
Differential Revision: https://reviews.freebsd.org/D20175
50c146a61b