From 2677010e7793451c20d895c477c4dc76f6e6a10e Mon Sep 17 00:00:00 2001 From: Samiullah Khawaja Date: Thu, 10 Jul 2025 21:12:03 +0000 Subject: Add support to set NAPI threaded for individual NAPI A net device has a threaded sysctl that can be used to enable threaded NAPI polling on all of the NAPI contexts under that device. Allow enabling threaded NAPI polling at individual NAPI level using netlink. Extend the netlink operation `napi-set` and allow setting the threaded attribute of a NAPI. This will enable the threaded polling on a NAPI context. Add a test in `nl_netdev.py` that verifies various cases of threaded NAPI being set at NAPI and at device level. Tested ./tools/testing/selftests/net/nl_netdev.py TAP version 13 1..7 ok 1 nl_netdev.empty_check ok 2 nl_netdev.lo_check ok 3 nl_netdev.page_pool_check ok 4 nl_netdev.napi_list_check ok 5 nl_netdev.dev_set_threaded ok 6 nl_netdev.napi_set_threaded ok 7 nl_netdev.nsim_rxq_reset_down # Totals: pass:7 fail:0 xfail:0 xpass:0 skip:0 error:0 Signed-off-by: Samiullah Khawaja Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250710211203.3979655-1-skhawaja@google.com Signed-off-by: Jakub Kicinski --- net/core/dev.c | 30 +++++++++++++++++++++++++++--- 1 file changed, 27 insertions(+), 3 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 19ddc3e6990a..621a639aeba1 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6961,6 +6961,31 @@ static void napi_stop_kthread(struct napi_struct *napi) napi->thread = NULL; } +int napi_set_threaded(struct napi_struct *napi, bool threaded) +{ + if (threaded) { + if (!napi->thread) { + int err = napi_kthread_create(napi); + + if (err) + return err; + } + } + + if (napi->config) + napi->config->threaded = threaded; + + if (!threaded && napi->thread) { + napi_stop_kthread(napi); + } else { + /* Make sure kthread is created before THREADED bit is set. */ + smp_mb__before_atomic(); + assign_bit(NAPI_STATE_THREADED, &napi->state, threaded); + } + + return 0; +} + int dev_set_threaded(struct net_device *dev, bool threaded) { struct napi_struct *napi; @@ -6968,9 +6993,6 @@ int dev_set_threaded(struct net_device *dev, bool threaded) netdev_assert_locked_or_invisible(dev); - if (dev->threaded == threaded) - return 0; - if (threaded) { list_for_each_entry(napi, &dev->napi_list, dev_list) { if (!napi->thread) { @@ -7221,6 +7243,8 @@ static void napi_restore_config(struct napi_struct *n) napi_hash_add(n); n->config->napi_id = n->napi_id; } + + WARN_ON_ONCE(napi_set_threaded(n, n->config->threaded)); } static void napi_save_config(struct napi_struct *n) -- cgit v1.2.3