[RFC,bpf-next,v2,2/9] net: add SO_BUSY_POLL_BUDGET socket option

Message ID	20201105102812.152836-3-bjorn.topel@gmail.com (mailing list archive)
State	RFC
Delegated to:	BPF
Headers	show Return-Path: <SRS0=NbGg=EL=vger.kernel.org=bpf-owner@kernel.org> From: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= <bjorn.topel@gmail.com> To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= <bjorn.topel@intel.com>, magnus.karlsson@intel.com, ast@kernel.org, daniel@iogearbox.net, maciej.fijalkowski@intel.com, sridhar.samudrala@intel.com, jesse.brandeburg@intel.com, qi.z.zhang@intel.com, kuba@kernel.org, edumazet@google.com, intel-wired-lan@lists.osuosl.org, jonathan.lemon@gmail.com Subject: [RFC PATCH bpf-next v2 2/9] net: add SO_BUSY_POLL_BUDGET socket option Date: Thu, 5 Nov 2020 11:28:05 +0100 Message-Id: <20201105102812.152836-3-bjorn.topel@gmail.com> In-Reply-To: <20201105102812.152836-1-bjorn.topel@gmail.com> References: <20201105102812.152836-1-bjorn.topel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	Introduce preferred busy-polling \| expand [RFC,bpf-next,v2,0/9] Introduce preferred busy-polling [RFC,bpf-next,v2,1/9] net: introduce preferred busy-polling [RFC,bpf-next,v2,2/9] net: add SO_BUSY_POLL_BUDGET socket option [RFC,bpf-next,v2,3/9] xsk: add support for recvmsg() [RFC,bpf-next,v2,4/9] xsk: check need wakeup flag in sendmsg() [RFC,bpf-next,v2,5/9] xsk: add busy-poll support for {recv,send}msg() [RFC,bpf-next,v2,6/9] xsk: propagate napi_id to XDP socket Rx path [RFC,bpf-next,v2,7/9] samples/bpf: use recvfrom() in xdpsock [RFC,bpf-next,v2,8/9] samples/bpf: add busy-poll support to xdpsock [RFC,bpf-next,v2,9/9] samples/bpf: add option to set the busy-poll budget

diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h index 538359642554..57420356ce4c 100644 --- a/arch/alpha/include/uapi/asm/socket.h +++ b/arch/alpha/include/uapi/asm/socket.h @@ -125,6 +125,7 @@ #define SO_DETACH_REUSEPORT_BPF 68 #define SO_PREFER_BUSY_POLL 69 +#define SO_BUSY_POLL_BUDGET 70 #if !defined(__KERNEL__) diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h index e406e73b5e6e..2d949969313b 100644 --- a/arch/mips/include/uapi/asm/socket.h +++ b/arch/mips/include/uapi/asm/socket.h @@ -136,6 +136,7 @@ #define SO_DETACH_REUSEPORT_BPF 68 #define SO_PREFER_BUSY_POLL 69 +#define SO_BUSY_POLL_BUDGET 70 #if !defined(__KERNEL__) diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h index 1bc46200889d..f60904329bbc 100644 --- a/arch/parisc/include/uapi/asm/socket.h +++ b/arch/parisc/include/uapi/asm/socket.h @@ -117,6 +117,7 @@ #define SO_DETACH_REUSEPORT_BPF 0x4042 #define SO_PREFER_BUSY_POLL 0x4043 +#define SO_BUSY_POLL_BUDGET 0x4044 #if !defined(__KERNEL__) diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h index 99688cf673a4..848a22fbac20 100644 --- a/arch/sparc/include/uapi/asm/socket.h +++ b/arch/sparc/include/uapi/asm/socket.h @@ -118,6 +118,7 @@ #define SO_DETACH_REUSEPORT_BPF 0x0047 #define SO_PREFER_BUSY_POLL 0x0048 +#define SO_BUSY_POLL_BUDGET 0x0049 #if !defined(__KERNEL__) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index e11fab3a0b9e..73c346e503d7 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -397,7 +397,8 @@ static void ep_busy_loop(struct eventpoll *ep, int nonblock) unsigned int napi_id = READ_ONCE(ep->napi_id); if ((napi_id >= MIN_NAPI_ID) && net_busy_loop_on()) - napi_busy_loop(napi_id, nonblock ? NULL : ep_busy_loop_end, ep, false); + napi_busy_loop(napi_id, nonblock ? NULL : ep_busy_loop_end, ep, false, + BUSY_POLL_BUDGET); } static inline void ep_reset_busy_poll_napi_id(struct eventpoll *ep) diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h index 0292b8353d7e..b4f653cc15a7 100644 --- a/include/net/busy_poll.h +++ b/include/net/busy_poll.h @@ -23,6 +23,8 @@ */ #define MIN_NAPI_ID ((unsigned int)(NR_CPUS + 1)) +#define BUSY_POLL_BUDGET 8 + #ifdef CONFIG_NET_RX_BUSY_POLL struct napi_struct; @@ -43,7 +45,7 @@ bool sk_busy_loop_end(void *p, unsigned long start_time); 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); #else /* CONFIG_NET_RX_BUSY_POLL */ static inline unsigned long net_busy_loop_on(void) @@ -106,7 +108,8 @@ static inline void sk_busy_loop(struct sock *sk, int nonblock) if (napi_id >= MIN_NAPI_ID) napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk, - READ_ONCE(sk->sk_prefer_busy_poll)); + READ_ONCE(sk->sk_prefer_busy_poll), + sk->sk_busy_poll_budget ?: BUSY_POLL_BUDGET); #endif } diff --git a/include/net/sock.h b/include/net/sock.h index 716960a15e83..1ddfb4a2dac2 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -481,6 +481,7 @@ struct sock { kuid_t sk_uid; #ifdef CONFIG_NET_RX_BUSY_POLL u8 sk_prefer_busy_poll; + u16 sk_busy_poll_budget; #endif struct pid *sk_peer_pid; const struct cred *sk_peer_cred; diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h index 7dd02408b7ce..4dcd13d097a9 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -120,6 +120,7 @@ #define SO_DETACH_REUSEPORT_BPF 68 #define SO_PREFER_BUSY_POLL 69 +#define SO_BUSY_POLL_BUDGET 70 #if !defined(__KERNEL__) diff --git a/net/core/dev.c b/net/core/dev.c index 49015b059549..33c67004f2ad 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6492,8 +6492,6 @@ 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) { @@ -6513,7 +6511,8 @@ 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; @@ -6545,21 +6544,21 @@ 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); @@ -6602,8 +6601,8 @@ void napi_busy_loop(unsigned int napi_id, 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) @@ -6616,7 +6615,7 @@ void napi_busy_loop(unsigned int napi_id, 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(); @@ -6627,7 +6626,7 @@ void napi_busy_loop(unsigned int napi_id, 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 248f6a763661..e08d5a6ae9d4 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1165,6 +1165,16 @@ int sock_setsockopt(struct socket *sock, int level, int optname, else sk->sk_prefer_busy_poll = valbool; break; + case SO_BUSY_POLL_BUDGET: + if (val > sk->sk_busy_poll_budget && !capable(CAP_NET_ADMIN)) { + ret = -EPERM; + } else { + if (val < 0) + ret = -EINVAL; + else + sk->sk_busy_poll_budget = val; + } + break; #endif case SO_MAX_PACING_RATE:

[RFC,bpf-next,v2,2/9] net: add SO_BUSY_POLL_BUDGET socket option

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