svn commit: r347542 - in stable/12: share/man/man4 sys/net
Stephen Hurd
shurd at FreeBSD.org
Mon May 13 18:48:10 UTC 2019
Author: shurd
Date: Mon May 13 18:48:08 2019
New Revision: 347542
URL: https://svnweb.freebsd.org/changeset/base/347542
Log:
MFC r346708:
iflib: Better control over queue core assignment
By default, cores are now assigned to queues in a sequential
manner rather than all NICs starting at the first core. On a four-core
system with two NICs each using two queue pairs, the nic:queue -> core
mapping has changed from this:
0:0 -> 0, 0:1 -> 1
1:0 -> 0, 1:1 -> 1
To this:
0:0 -> 0, 0:1 -> 1
1:0 -> 2, 1:1 -> 3
Additionally, a device can now be configured to use separate cores for TX
and RX queues.
Two new tunables have been added, dev.X.Y.iflib.separate_txrx and
dev.X.Y.iflib.core_offset. If core_offset is set, the NIC is not part
of the auto-assigned sequence.
Reviewed by: marius
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D20029
Modified:
stable/12/share/man/man4/iflib.4
stable/12/sys/net/iflib.c
Directory Properties:
stable/12/ (props changed)
Modified: stable/12/share/man/man4/iflib.4
==============================================================================
--- stable/12/share/man/man4/iflib.4 Mon May 13 18:40:01 2019 (r347541)
+++ stable/12/share/man/man4/iflib.4 Mon May 13 18:48:08 2019 (r347542)
@@ -55,6 +55,16 @@ If zero, the number of TX queues is derived from the n
socket connected to the controller.
.It Va disable_msix
Disables MSI-X interrupts for the device.
+.It Va core_offset
+Specifies a starting core offset to assign queues to.
+If the value is unspecified or 65535, cores are assigned sequentially across
+controllers.
+.It Va separate_txrx
+Requests that RX and TX queues not be paired on the same core.
+If this is zero or not set, an RX and TX queue pair will be assigned to each
+core.
+When set to a non-zero value, TX queues are assigned to cores following the
+last RX queue.
.El
.Pp
These
Modified: stable/12/sys/net/iflib.c
==============================================================================
--- stable/12/sys/net/iflib.c Mon May 13 18:40:01 2019 (r347541)
+++ stable/12/sys/net/iflib.c Mon May 13 18:48:08 2019 (r347542)
@@ -191,6 +191,9 @@ struct iflib_ctx {
uint16_t ifc_sysctl_qs_eq_override;
uint16_t ifc_sysctl_rx_budget;
uint16_t ifc_sysctl_tx_abdicate;
+ uint16_t ifc_sysctl_core_offset;
+#define CORE_OFFSET_UNSPECIFIED 0xffff
+ uint8_t ifc_sysctl_separate_txrx;
qidx_t ifc_sysctl_ntxds[8];
qidx_t ifc_sysctl_nrxds[8];
@@ -728,6 +731,18 @@ static void iflib_free_intr_mem(if_ctx_t ctx);
static struct mbuf * iflib_fixup_rx(struct mbuf *m);
#endif
+static SLIST_HEAD(cpu_offset_list, cpu_offset) cpu_offsets =
+ SLIST_HEAD_INITIALIZER(cpu_offsets);
+struct cpu_offset {
+ SLIST_ENTRY(cpu_offset) entries;
+ cpuset_t set;
+ unsigned int refcount;
+ uint16_t offset;
+};
+static struct mtx cpu_offset_mtx;
+MTX_SYSINIT(iflib_cpu_offset, &cpu_offset_mtx, "iflib_cpu_offset lock",
+ MTX_DEF);
+
NETDUMP_DEFINE(iflib);
#ifdef DEV_NETMAP
@@ -4401,6 +4416,71 @@ iflib_reset_qvalues(if_ctx_t ctx)
}
}
+static uint16_t
+get_ctx_core_offset(if_ctx_t ctx)
+{
+ if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
+ struct cpu_offset *op;
+ uint16_t qc;
+ uint16_t ret = ctx->ifc_sysctl_core_offset;
+
+ if (ret != CORE_OFFSET_UNSPECIFIED)
+ return (ret);
+
+ if (ctx->ifc_sysctl_separate_txrx)
+ qc = scctx->isc_ntxqsets + scctx->isc_nrxqsets;
+ else
+ qc = max(scctx->isc_ntxqsets, scctx->isc_nrxqsets);
+
+ mtx_lock(&cpu_offset_mtx);
+ SLIST_FOREACH(op, &cpu_offsets, entries) {
+ if (CPU_CMP(&ctx->ifc_cpus, &op->set) == 0) {
+ ret = op->offset;
+ op->offset += qc;
+ MPASS(op->refcount < UINT_MAX);
+ op->refcount++;
+ break;
+ }
+ }
+ if (ret == CORE_OFFSET_UNSPECIFIED) {
+ ret = 0;
+ op = malloc(sizeof(struct cpu_offset), M_IFLIB,
+ M_NOWAIT | M_ZERO);
+ if (op == NULL) {
+ device_printf(ctx->ifc_dev,
+ "allocation for cpu offset failed.\n");
+ } else {
+ op->offset = qc;
+ op->refcount = 1;
+ CPU_COPY(&ctx->ifc_cpus, &op->set);
+ SLIST_INSERT_HEAD(&cpu_offsets, op, entries);
+ }
+ }
+ mtx_unlock(&cpu_offset_mtx);
+
+ return (ret);
+}
+
+static void
+unref_ctx_core_offset(if_ctx_t ctx)
+{
+ struct cpu_offset *op, *top;
+
+ mtx_lock(&cpu_offset_mtx);
+ SLIST_FOREACH_SAFE(op, &cpu_offsets, entries, top) {
+ if (CPU_CMP(&ctx->ifc_cpus, &op->set) == 0) {
+ MPASS(op->refcount > 0);
+ op->refcount--;
+ if (op->refcount == 0) {
+ SLIST_REMOVE(&cpu_offsets, op, cpu_offset, entries);
+ free(op, M_IFLIB);
+ }
+ break;
+ }
+ }
+ mtx_unlock(&cpu_offset_mtx);
+}
+
int
iflib_device_register(device_t dev, void *sc, if_shared_ctx_t sctx, if_ctx_t *ctxp)
{
@@ -4551,6 +4631,11 @@ iflib_device_register(device_t dev, void *sc, if_share
goto fail_queues;
/*
+ * Now that we know how many queues there are, get the core offset.
+ */
+ ctx->ifc_sysctl_core_offset = get_ctx_core_offset(ctx);
+
+ /*
* Group taskqueues aren't properly set up until SMP is started,
* so we disable interrupts until we can handle them post
* SI_SUB_SMP.
@@ -4971,6 +5056,7 @@ iflib_device_deregister(if_ctx_t ctx)
iflib_rx_structures_free(ctx);
if (ctx->ifc_flags & IFC_SC_ALLOCATED)
free(ctx->ifc_softc, M_IFLIB);
+ unref_ctx_core_offset(ctx);
STATE_LOCK_DESTROY(ctx);
free(ctx, M_IFLIB);
return (0);
@@ -5589,7 +5675,7 @@ find_child_with_core(int cpu, struct cpu_group *grp)
* Find the nth "close" core to the specified core
* "close" is defined as the deepest level that shares
* at least an L2 cache. With threads, this will be
- * threads on the same core. If the sahred cache is L3
+ * threads on the same core. If the shared cache is L3
* or higher, simply returns the same core.
*/
static int
@@ -5671,10 +5757,12 @@ static inline int
iflib_irq_set_affinity(if_ctx_t ctx, int irq, iflib_intr_type_t type, int qid,
struct grouptask *gtask, struct taskqgroup *tqg, void *uniq, const char *name)
{
- int cpuid;
- int err, tid;
+ int co, cpuid, err, tid;
- cpuid = find_nth(ctx, qid);
+ co = ctx->ifc_sysctl_core_offset;
+ if (ctx->ifc_sysctl_separate_txrx && type == IFLIB_INTR_TX)
+ co += ctx->ifc_softc_ctx.isc_nrxqsets;
+ cpuid = find_nth(ctx, qid + co);
tid = get_core_offset(ctx, type, qid);
MPASS(tid >= 0);
cpuid = find_close_core(cpuid, tid);
@@ -6264,6 +6352,13 @@ iflib_add_device_sysctl_pre(if_ctx_t ctx)
SYSCTL_ADD_U16(ctx_list, oid_list, OID_AUTO, "tx_abdicate",
CTLFLAG_RWTUN, &ctx->ifc_sysctl_tx_abdicate, 0,
"cause tx to abdicate instead of running to completion");
+ ctx->ifc_sysctl_core_offset = CORE_OFFSET_UNSPECIFIED;
+ SYSCTL_ADD_U16(ctx_list, oid_list, OID_AUTO, "core_offset",
+ CTLFLAG_RDTUN, &ctx->ifc_sysctl_core_offset, 0,
+ "offset to start using cores at");
+ SYSCTL_ADD_U8(ctx_list, oid_list, OID_AUTO, "separate_txrx",
+ CTLFLAG_RDTUN, &ctx->ifc_sysctl_separate_txrx, 0,
+ "use separate cores for TX and RX");
/* XXX change for per-queue sizes */
SYSCTL_ADD_PROC(ctx_list, oid_list, OID_AUTO, "override_ntxds",
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