diff mbox series

net: enable timestamp static key if CPU isolation is configured

Message ID ZgR1JFNf8bMkTAAm@tpad (mailing list archive)
State Superseded
Headers show
Series net: enable timestamp static key if CPU isolation is configured | expand

Checks

Context Check Description
netdev/series_format warning Single patches do not need cover letters; Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 951 this patch: 951
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 4 of 4 maintainers
netdev/build_clang success Errors and warnings before: 956 this patch: 956
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 962 this patch: 962
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 17 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Marcelo Tosatti March 27, 2024, 7:36 p.m. UTC
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: Marcelo Tosatti <mtosatti@redhat.com>

---
v2: mention SOF_TIMESTAMPING_OPT_TX_SWHW in the commit log (Willem de Bruijn / Paolo Abeni)
v3: SOF_TIMESTAMPING_OPT_TX_SWHW is irrelevant (Willem de Bruijn)
v4: additional changelog improvements (Willem de Bruijn)
v5: late initcall not necessary, can use subsys initcall (Willem de Bruijn)
v6: rebase against net-next, change subject (Jakub Kicinski)
diff mbox series

Patch

diff --git a/net/core/dev.c b/net/core/dev.c
index 5d36a634f468..48c725caa130 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -157,6 +157,7 @@ 
 #include <net/page_pool/types.h>
 #include <net/page_pool/helpers.h>
 #include <net/rps.h>
+#include <linux/sched/isolation.h>
 
 #include "dev.h"
 #include "net-sysfs.h"
@@ -11890,6 +11891,10 @@  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) {