From 7c951cafc0cb2e575f1d58677b95ac387ac0a5bd Mon Sep 17 00:00:00 2001 From: Björn Töpel Date: Mon, 30 Nov 2020 19:51:57 +0100 Subject: net: Add SO_BUSY_POLL_BUDGET socket option MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This option lets a user set a per socket NAPI budget for busy-polling. If the options is not set, it will use the default of 8. Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann Reviewed-by: Jakub Kicinski Link: https://lore.kernel.org/bpf/20201130185205.196029-3-bjorn.topel@gmail.com --- net/core/dev.c | 21 ++++++++++----------- net/core/sock.c | 10 ++++++++++ 2 files changed, 20 insertions(+), 11 deletions(-) (limited to 'net/core') diff --git a/net/core/dev.c b/net/core/dev.c index 6f8d2cffb7c5..7a1e5936c67f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6496,8 +6496,6 @@ static struct napi_struct *napi_by_id(unsigned int napi_id) #if defined(CONFIG_NET_RX_BUSY_POLL) -#define BUSY_POLL_BUDGET 8 - static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule) { if (!skip_schedule) { @@ -6517,7 +6515,8 @@ static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule) clear_bit(NAPI_STATE_SCHED, &napi->state); } -static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll) +static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll, + u16 budget) { bool skip_schedule = false; unsigned long timeout; @@ -6549,21 +6548,21 @@ static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool /* All we really want here is to re-enable device interrupts. * Ideally, a new ndo_busy_poll_stop() could avoid another round. */ - rc = napi->poll(napi, BUSY_POLL_BUDGET); + rc = napi->poll(napi, budget); /* We can't gro_normal_list() here, because napi->poll() might have * rearmed the napi (napi_complete_done()) in which case it could * already be running on another CPU. */ - trace_napi_poll(napi, rc, BUSY_POLL_BUDGET); + trace_napi_poll(napi, rc, budget); netpoll_poll_unlock(have_poll_lock); - if (rc == BUSY_POLL_BUDGET) + if (rc == budget) __busy_poll_stop(napi, skip_schedule); local_bh_enable(); } void napi_busy_loop(unsigned int napi_id, bool (*loop_end)(void *, unsigned long), - void *loop_end_arg, bool prefer_busy_poll) + void *loop_end_arg, bool prefer_busy_poll, u16 budget) { unsigned long start_time = loop_end ? busy_loop_current_time() : 0; int (*napi_poll)(struct napi_struct *napi, int budget); @@ -6606,8 +6605,8 @@ restart: have_poll_lock = netpoll_poll_lock(napi); napi_poll = napi->poll; } - work = napi_poll(napi, BUSY_POLL_BUDGET); - trace_napi_poll(napi, work, BUSY_POLL_BUDGET); + work = napi_poll(napi, budget); + trace_napi_poll(napi, work, budget); gro_normal_list(napi); count: if (work > 0) @@ -6620,7 +6619,7 @@ count: if (unlikely(need_resched())) { if (napi_poll) - busy_poll_stop(napi, have_poll_lock, prefer_busy_poll); + busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget); preempt_enable(); rcu_read_unlock(); cond_resched(); @@ -6631,7 +6630,7 @@ count: cpu_relax(); } if (napi_poll) - busy_poll_stop(napi, have_poll_lock, prefer_busy_poll); + busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget); preempt_enable(); out: rcu_read_unlock(); diff --git a/net/core/sock.c b/net/core/sock.c index e05f2e52b5a8..d422a6808405 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1165,6 +1165,16 @@ set_sndbuf: else WRITE_ONCE(sk->sk_prefer_busy_poll, valbool); break; + case SO_BUSY_POLL_BUDGET: + if (val > READ_ONCE(sk->sk_busy_poll_budget) && !capable(CAP_NET_ADMIN)) { + ret = -EPERM; + } else { + if (val < 0 || val > U16_MAX) + ret = -EINVAL; + else + WRITE_ONCE(sk->sk_busy_poll_budget, val); + } + break; #endif case SO_MAX_PACING_RATE: -- cgit v1.2.3