Add tunable to allow interrupts on hyperthreaded cores

Enabling interrupts on htt cores has benefits to workloads which are primarily
interrupt driven by increasing the logical cores available for interrupt handling.
The tunable is named machdep.hyperthreading_intr_allowed

Reviewed by:	kib, jhb
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D22233
This commit is contained in:
Andrew Gallatin 2019-11-04 19:30:19 +00:00
parent d6dbfed81e
commit bb7aaac379

View File

@ -144,6 +144,11 @@ static int hyperthreading_allowed = 1;
SYSCTL_INT(_machdep, OID_AUTO, hyperthreading_allowed, CTLFLAG_RDTUN,
&hyperthreading_allowed, 0, "Use Intel HTT logical CPUs");
static int hyperthreading_intr_allowed = 0;
SYSCTL_INT(_machdep, OID_AUTO, hyperthreading_intr_allowed, CTLFLAG_RDTUN,
&hyperthreading_intr_allowed, 0,
"Allow interrupts on HTT logical CPUs");
static struct topo_node topo_root;
static int pkg_id_shift;
@ -1121,7 +1126,8 @@ set_interrupt_apic_ids(void)
continue;
/* Don't let hyperthreads service interrupts. */
if (cpu_info[apic_id].cpu_hyperthread)
if (cpu_info[apic_id].cpu_hyperthread &&
!hyperthreading_intr_allowed)
continue;
intr_add_cpu(i);