/*
* netisr CPU affinity lookup given just the hash and hashtype.
*/
u_int
rss_hash2cpuid(uint32_t hash_val, uint32_t hash_type)
{
switch (hash_type) {
case M_HASHTYPE_RSS_IPV4:
case M_HASHTYPE_RSS_TCP_IPV4:
return (rss_getcpu(rss_getbucket(hash_val)));
default:
return (NETISR_CPUID_NONE);
}
}
static int
sysctl_rss_bucket_mapping(SYSCTL_HANDLER_ARGS)
{
struct sbuf *sb;
int error;
int i;
error = 0;
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
sb = sbuf_new_for_sysctl(NULL, NULL, 512, req);
if (sb == NULL)
return (ENOMEM);
for (i = 0; i < rss_buckets; i++) {
sbuf_printf(sb, "%s%d:%d", i == 0 ? "" : " ",
i,
rss_getcpu(i));
}
error = sbuf_finish(sb);
sbuf_delete(sb);
return (error);
}
void
in_pcbgroup_init(struct inpcbinfo *pcbinfo, u_int hashfields,
int hash_nelements)
{
struct inpcbgroup *pcbgroup;
u_int numpcbgroups, pgn;
/*
* Only enable connection groups for a protocol if it has been
* specifically requested.
*/
if (hashfields == IPI_HASHFIELDS_NONE)
return;
/*
* Connection groups are about multi-processor load distribution,
* lock contention, and connection CPU affinity. As such, no point
* in turning them on for a uniprocessor machine, it only wastes
* memory.
*/
if (mp_ncpus == 1)
return;
#ifdef RSS
/*
* If we're using RSS, then RSS determines the number of connection
* groups to use: one connection group per RSS bucket. If for some
* reason RSS isn't able to provide a number of buckets, disable
* connection groups entirely.
*
* XXXRW: Can this ever happen?
*/
numpcbgroups = rss_getnumbuckets();
if (numpcbgroups == 0)
return;
#else
/*
* Otherwise, we'll just use one per CPU for now. If we decide to
* do dynamic rebalancing a la RSS, we'll need similar logic here.
*/
numpcbgroups = mp_ncpus;
#endif
pcbinfo->ipi_hashfields = hashfields;
pcbinfo->ipi_pcbgroups = malloc(numpcbgroups *
sizeof(*pcbinfo->ipi_pcbgroups), M_PCB, M_WAITOK | M_ZERO);
pcbinfo->ipi_npcbgroups = numpcbgroups;
pcbinfo->ipi_wildbase = hashinit(hash_nelements, M_PCB,
&pcbinfo->ipi_wildmask);
for (pgn = 0; pgn < pcbinfo->ipi_npcbgroups; pgn++) {
pcbgroup = &pcbinfo->ipi_pcbgroups[pgn];
pcbgroup->ipg_hashbase = hashinit(hash_nelements, M_PCB,
&pcbgroup->ipg_hashmask);
INP_GROUP_LOCK_INIT(pcbgroup, "pcbgroup");
/*
* Initialise notional affinity of the pcbgroup -- for RSS,
* we want the same notion of affinity as NICs to be used. In
* the non-RSS case, just round robin for the time being.
*
* XXXRW: The notion of a bucket to CPU mapping is common at
* both pcbgroup and RSS layers -- does that mean that we
* should migrate it all from RSS to here, and just leave RSS
* responsible only for providing hashing and mapping funtions?
*/
#ifdef RSS
pcbgroup->ipg_cpu = rss_getcpu(pgn);
#else
pcbgroup->ipg_cpu = (pgn % mp_ncpus);
#endif
}
}
