| Message ID | ZgrUiLLtbEUf9SFn@tpad (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 2f3c7195a702178629575b637f3f9a91eabdab73 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,-v7] net: enable timestamp static key if CPU | expand |
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Mon, 1 Apr 2024 12:36:40 -0300 you wrote: > 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. > > [...] Here is the summary with links: - [net-next,-v7] net: enable timestamp static key if CPU https://git.kernel.org/netdev/net-next/c/2f3c7195a702 You are awesome, thank you!
diff --git a/net/core/dev.c b/net/core/dev.c index 5d36a634f468..718a00e70d53 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -78,6 +78,7 @@ #include <linux/slab.h> #include <linux/sched.h> #include <linux/sched/mm.h> +#include <linux/sched/isolation.h> #include <linux/smpboot.h> #include <linux/mutex.h> #include <linux/rwsem.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) {
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) v7: change location of linux/sched #include (Jakub Kicinski)