Commit 2f3c7195 authored by Marcelo Tosatti's avatar Marcelo Tosatti Committed by Jakub Kicinski
Browse files

net: enable timestamp static key if CPU 



For systems that use CPU isolation (via nohz_full), creating or destroying
a socket with SO_TIMESTAMP, SO_TIMESTAMPNS or SO_TIMESTAMPING with flag
SOF_TIMESTAMPING_RX_SOFTWARE will cause a static key to be enabled/disabled.
This in turn causes undesired IPIs to isolated CPUs.

So enable the static key unconditionally, if CPU isolation is enabled,
thus avoiding the IPIs.

Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: default avatarWillem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/ZgrUiLLtbEUf9SFn@tpad


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 34c58c89

net/core/dev.c

+5 −0
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ 
#include <linux/hash.h>

#include <linux/slab.h>

#include <linux/sched.h>

#include <linux/sched/isolation.h>

#include <linux/sched/mm.h>

#include <linux/smpboot.h>

#include <linux/mutex.h>
@@ -11911,6 +11912,10 @@ static int __init net_dev_init(void) 
				       NULL, dev_cpu_dead);

	WARN_ON(rc < 0);

	rc = 0;



	/* avoid static key IPIs to isolated CPUs */

	if (housekeeping_enabled(HK_TYPE_MISC))

		net_enable_timestamp();

out:

	if (rc < 0) {

		for_each_possible_cpu(i) {