Only use a power of 2 for the number of receive and transmit queues.

Using other values causes VMXNET3_CMD_ENABLE to fail.  The Linux
driver also enforces this restriction.

Reviewed by:	bryanv
MFC after:	1 week
Sponsored by:	Norse
Differential Revision:	https://reviews.freebsd.org/D4139
This commit is contained in:
jhb 2015-11-16 21:36:50 +00:00
parent 4a83aa80d5
commit afb0cf7537

View File

@ -510,6 +510,13 @@ vmxnet3_check_version(struct vmxnet3_softc *sc)
return (0);
}
static int
trunc_powerof2(int val)
{
return (1U << (fls(val) - 1));
}
static void
vmxnet3_initial_config(struct vmxnet3_softc *sc)
{
@ -520,14 +527,14 @@ vmxnet3_initial_config(struct vmxnet3_softc *sc)
nqueue = VMXNET3_DEF_TX_QUEUES;
if (nqueue > mp_ncpus)
nqueue = mp_ncpus;
sc->vmx_max_ntxqueues = nqueue;
sc->vmx_max_ntxqueues = trunc_powerof2(nqueue);
nqueue = vmxnet3_tunable_int(sc, "rxnqueue", vmxnet3_default_rxnqueue);
if (nqueue > VMXNET3_MAX_RX_QUEUES || nqueue < 1)
nqueue = VMXNET3_DEF_RX_QUEUES;
if (nqueue > mp_ncpus)
nqueue = mp_ncpus;
sc->vmx_max_nrxqueues = nqueue;
sc->vmx_max_nrxqueues = trunc_powerof2(nqueue);
if (vmxnet3_tunable_int(sc, "mq_disable", vmxnet3_mq_disable)) {
sc->vmx_max_nrxqueues = 1;