Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

 * Fix include order for bison/flex-generated C files, from Ben Hutchings

 * Build fixes and documentation corrections from David Ahern

 * Group parsing support, from Jiri Olsa

 * UI/gtk refactorings and improvements from Namhyung Kim

 * NULL deref fix for perf script, from Namhyung Kim

 * Assorted cleanups from Robert Richter

 * Let O= makes handle relative paths, from Steven Rostedt

 * perf script python fixes, from Feng Tang.

 * Improve 'perf lock' error message when the needed tracepoints
   are not present, from David Ahern.

 * Initial bash completion support, from Frederic Weisbecker

 * Allow building without libelf, from Namhyung Kim.

 * Support DWARF CFI based unwind to have callchains when %bp
   based unwinding is not possible, from Jiri Olsa.

 * Symbol resolution fixes, while fixing support PPC64 files with an .opt ELF
   section was the end goal, several fixes for code that handles all
   architectures and cleanups are included, from Cody Schafer.

 * Add a description for the JIT interface, from Andi Kleen.

 * Assorted fixes for Documentation and build in 32 bit, from Robert Richter

 * Add support for non-tracepoint events in perf script python, from Feng Tang

 * Cache the libtraceevent event_format associated to each evsel early, so that we
   avoid relookups, i.e. calling pevent_find_event repeatedly when processing
   tracepoint events.

   [ This is to reduce the surface contact with libtraceevents and make clear what
     is that the perf tools needs from that lib: so far parsing the common and per
     event fields. ]

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 330 insertions, 23 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 803cbfe82fbc..3f1bcff0b10b 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -50,6 +50,9 @@ int sysctl_tcp_retrans_collapse __read_mostly = 1;
  */
 int sysctl_tcp_workaround_signed_windows __read_mostly = 0;
 
+/* Default TSQ limit of two TSO segments */
+int sysctl_tcp_limit_output_bytes __read_mostly = 131072;
+
 /* This limits the percentage of the congestion window which we
  * will allow a single TSO frame to consume.  Building TSO frames
  * which are too large can cause TCP streams to be bursty.
@@ -65,6 +68,8 @@ int sysctl_tcp_slow_start_after_idle __read_mostly = 1;
 int sysctl_tcp_cookie_size __read_mostly = 0; /* TCP_COOKIE_MAX */
 EXPORT_SYMBOL_GPL(sysctl_tcp_cookie_size);
 
+static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
+			   int push_one, gfp_t gfp);
 
 /* Account for new data that has been sent to the network. */
 static void tcp_event_new_data_sent(struct sock *sk, const struct sk_buff *skb)
@@ -380,15 +385,17 @@ static inline bool tcp_urg_mode(const struct tcp_sock *tp)
 #define OPTION_MD5		(1 << 2)
 #define OPTION_WSCALE		(1 << 3)
 #define OPTION_COOKIE_EXTENSION	(1 << 4)
+#define OPTION_FAST_OPEN_COOKIE	(1 << 8)
 
 struct tcp_out_options {
-	u8 options;		/* bit field of OPTION_* */
+	u16 options;		/* bit field of OPTION_* */
+	u16 mss;		/* 0 to disable */
 	u8 ws;			/* window scale, 0 to disable */
 	u8 num_sack_blocks;	/* number of SACK blocks to include */
 	u8 hash_size;		/* bytes in hash_location */
-	u16 mss;		/* 0 to disable */
-	__u32 tsval, tsecr;	/* need to include OPTION_TS */
 	__u8 *hash_location;	/* temporary pointer, overloaded */
+	__u32 tsval, tsecr;	/* need to include OPTION_TS */
+	struct tcp_fastopen_cookie *fastopen_cookie;	/* Fast open cookie */
 };
 
 /* The sysctl int routines are generic, so check consistency here.
@@ -437,7 +444,7 @@ static u8 tcp_cookie_size_check(u8 desired)
 static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
 			      struct tcp_out_options *opts)
 {
-	u8 options = opts->options;	/* mungable copy */
+	u16 options = opts->options;	/* mungable copy */
 
 	/* Having both authentication and cookies for security is redundant,
 	 * and there's certainly not enough room.  Instead, the cookie-less
@@ -559,6 +566,21 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
 
 		tp->rx_opt.dsack = 0;
 	}
+
+	if (unlikely(OPTION_FAST_OPEN_COOKIE & options)) {
+		struct tcp_fastopen_cookie *foc = opts->fastopen_cookie;
+
+		*ptr++ = htonl((TCPOPT_EXP << 24) |
+			       ((TCPOLEN_EXP_FASTOPEN_BASE + foc->len) << 16) |
+			       TCPOPT_FASTOPEN_MAGIC);
+
+		memcpy(ptr, foc->val, foc->len);
+		if ((foc->len & 3) == 2) {
+			u8 *align = ((u8 *)ptr) + foc->len;
+			align[0] = align[1] = TCPOPT_NOP;
+		}
+		ptr += (foc->len + 3) >> 2;
+	}
 }
 
 /* Compute TCP options for SYN packets. This is not the final
@@ -574,6 +596,7 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
 	u8 cookie_size = (!tp->rx_opt.cookie_out_never && cvp != NULL) ?
 			 tcp_cookie_size_check(cvp->cookie_desired) :
 			 0;
+	struct tcp_fastopen_request *fastopen = tp->fastopen_req;
 
 #ifdef CONFIG_TCP_MD5SIG
 	*md5 = tp->af_specific->md5_lookup(sk, sk);
@@ -614,6 +637,16 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
 			remaining -= TCPOLEN_SACKPERM_ALIGNED;
 	}
 
+	if (fastopen && fastopen->cookie.len >= 0) {
+		u32 need = TCPOLEN_EXP_FASTOPEN_BASE + fastopen->cookie.len;
+		need = (need + 3) & ~3U;  /* Align to 32 bits */
+		if (remaining >= need) {
+			opts->options |= OPTION_FAST_OPEN_COOKIE;
+			opts->fastopen_cookie = &fastopen->cookie;
+			remaining -= need;
+			tp->syn_fastopen = 1;
+		}
+	}
 	/* Note that timestamps are required by the specification.
 	 *
 	 * Odd numbers of bytes are prohibited by the specification, ensuring
@@ -783,6 +816,156 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb
 	return size;
 }
 
+
+/* TCP SMALL QUEUES (TSQ)
+ *
+ * TSQ goal is to keep small amount of skbs per tcp flow in tx queues (qdisc+dev)
+ * to reduce RTT and bufferbloat.
+ * We do this using a special skb destructor (tcp_wfree).
+ *
+ * Its important tcp_wfree() can be replaced by sock_wfree() in the event skb
+ * needs to be reallocated in a driver.
+ * The invariant being skb->truesize substracted from sk->sk_wmem_alloc
+ *
+ * Since transmit from skb destructor is forbidden, we use a tasklet
+ * to process all sockets that eventually need to send more skbs.
+ * We use one tasklet per cpu, with its own queue of sockets.
+ */
+struct tsq_tasklet {
+	struct tasklet_struct	tasklet;
+	struct list_head	head; /* queue of tcp sockets */
+};
+static DEFINE_PER_CPU(struct tsq_tasklet, tsq_tasklet);
+
+static void tcp_tsq_handler(struct sock *sk)
+{
+	if ((1 << sk->sk_state) &
+	    (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_CLOSING |
+	     TCPF_CLOSE_WAIT  | TCPF_LAST_ACK))
+		tcp_write_xmit(sk, tcp_current_mss(sk), 0, 0, GFP_ATOMIC);
+}
+/*
+ * One tasklest per cpu tries to send more skbs.
+ * We run in tasklet context but need to disable irqs when
+ * transfering tsq->head because tcp_wfree() might
+ * interrupt us (non NAPI drivers)
+ */
+static void tcp_tasklet_func(unsigned long data)
+{
+	struct tsq_tasklet *tsq = (struct tsq_tasklet *)data;
+	LIST_HEAD(list);
+	unsigned long flags;
+	struct list_head *q, *n;
+	struct tcp_sock *tp;
+	struct sock *sk;
+
+	local_irq_save(flags);
+	list_splice_init(&tsq->head, &list);
+	local_irq_restore(flags);
+
+	list_for_each_safe(q, n, &list) {
+		tp = list_entry(q, struct tcp_sock, tsq_node);
+		list_del(&tp->tsq_node);
+
+		sk = (struct sock *)tp;
+		bh_lock_sock(sk);
+
+		if (!sock_owned_by_user(sk)) {
+			tcp_tsq_handler(sk);
+		} else {
+			/* defer the work to tcp_release_cb() */
+			set_bit(TCP_TSQ_DEFERRED, &tp->tsq_flags);
+		}
+		bh_unlock_sock(sk);
+
+		clear_bit(TSQ_QUEUED, &tp->tsq_flags);
+		sk_free(sk);
+	}
+}
+
+#define TCP_DEFERRED_ALL ((1UL << TCP_TSQ_DEFERRED) |		\
+			  (1UL << TCP_WRITE_TIMER_DEFERRED) |	\
+			  (1UL << TCP_DELACK_TIMER_DEFERRED) |	\
+			  (1UL << TCP_MTU_REDUCED_DEFERRED))
+/**
+ * tcp_release_cb - tcp release_sock() callback
+ * @sk: socket
+ *
+ * called from release_sock() to perform protocol dependent
+ * actions before socket release.
+ */
+void tcp_release_cb(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	unsigned long flags, nflags;
+
+	/* perform an atomic operation only if at least one flag is set */
+	do {
+		flags = tp->tsq_flags;
+		if (!(flags & TCP_DEFERRED_ALL))
+			return;
+		nflags = flags & ~TCP_DEFERRED_ALL;
+	} while (cmpxchg(&tp->tsq_flags, flags, nflags) != flags);
+
+	if (flags & (1UL << TCP_TSQ_DEFERRED))
+		tcp_tsq_handler(sk);
+
+	if (flags & (1UL << TCP_WRITE_TIMER_DEFERRED))
+		tcp_write_timer_handler(sk);
+
+	if (flags & (1UL << TCP_DELACK_TIMER_DEFERRED))
+		tcp_delack_timer_handler(sk);
+
+	if (flags & (1UL << TCP_MTU_REDUCED_DEFERRED))
+		sk->sk_prot->mtu_reduced(sk);
+}
+EXPORT_SYMBOL(tcp_release_cb);
+
+void __init tcp_tasklet_init(void)
+{
+	int i;
+
+	for_each_possible_cpu(i) {
+		struct tsq_tasklet *tsq = &per_cpu(tsq_tasklet, i);
+
+		INIT_LIST_HEAD(&tsq->head);
+		tasklet_init(&tsq->tasklet,
+			     tcp_tasklet_func,
+			     (unsigned long)tsq);
+	}
+}
+
+/*
+ * Write buffer destructor automatically called from kfree_skb.
+ * We cant xmit new skbs from this context, as we might already
+ * hold qdisc lock.
+ */
+void tcp_wfree(struct sk_buff *skb)
+{
+	struct sock *sk = skb->sk;
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (test_and_clear_bit(TSQ_THROTTLED, &tp->tsq_flags) &&
+	    !test_and_set_bit(TSQ_QUEUED, &tp->tsq_flags)) {
+		unsigned long flags;
+		struct tsq_tasklet *tsq;
+
+		/* Keep a ref on socket.
+		 * This last ref will be released in tcp_tasklet_func()
+		 */
+		atomic_sub(skb->truesize - 1, &sk->sk_wmem_alloc);
+
+		/* queue this socket to tasklet queue */
+		local_irq_save(flags);
+		tsq = &__get_cpu_var(tsq_tasklet);
+		list_add(&tp->tsq_node, &tsq->head);
+		tasklet_schedule(&tsq->tasklet);
+		local_irq_restore(flags);
+	} else {
+		sock_wfree(skb);
+	}
+}
+
 /* This routine actually transmits TCP packets queued in by
  * tcp_do_sendmsg().  This is used by both the initial
  * transmission and possible later retransmissions.
@@ -844,7 +1027,12 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 
 	skb_push(skb, tcp_header_size);
 	skb_reset_transport_header(skb);
-	skb_set_owner_w(skb, sk);
+
+	skb_orphan(skb);
+	skb->sk = sk;
+	skb->destructor = (sysctl_tcp_limit_output_bytes > 0) ?
+			  tcp_wfree : sock_wfree;
+	atomic_add(skb->truesize, &sk->sk_wmem_alloc);
 
 	/* Build TCP header and checksum it. */
 	th = tcp_hdr(skb);
@@ -1780,6 +1968,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 	while ((skb = tcp_send_head(sk))) {
 		unsigned int limit;
 
+
 		tso_segs = tcp_init_tso_segs(sk, skb, mss_now);
 		BUG_ON(!tso_segs);
 
@@ -1800,6 +1989,13 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 				break;
 		}
 
+		/* TSQ : sk_wmem_alloc accounts skb truesize,
+		 * including skb overhead. But thats OK.
+		 */
+		if (atomic_read(&sk->sk_wmem_alloc) >= sysctl_tcp_limit_output_bytes) {
+			set_bit(TSQ_THROTTLED, &tp->tsq_flags);
+			break;
+		}
 		limit = mss_now;
 		if (tso_segs > 1 && !tcp_urg_mode(tp))
 			limit = tcp_mss_split_point(sk, skb, mss_now,
@@ -1849,7 +2045,8 @@ void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss,
 	if (unlikely(sk->sk_state == TCP_CLOSE))
 		return;
 
-	if (tcp_write_xmit(sk, cur_mss, nonagle, 0, GFP_ATOMIC))
+	if (tcp_write_xmit(sk, cur_mss, nonagle, 0,
+			   sk_gfp_atomic(sk, GFP_ATOMIC)))
 		tcp_check_probe_timer(sk);
 }
 
@@ -2442,7 +2639,16 @@ int tcp_send_synack(struct sock *sk)
 	return tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
 }
 
-/* Prepare a SYN-ACK. */
+/**
+ * tcp_make_synack - Prepare a SYN-ACK.
+ * sk: listener socket
+ * dst: dst entry attached to the SYNACK
+ * req: request_sock pointer
+ * rvp: request_values pointer
+ *
+ * Allocate one skb and build a SYNACK packet.
+ * @dst is consumed : Caller should not use it again.
+ */
 struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 				struct request_sock *req,
 				struct request_values *rvp)
@@ -2461,14 +2667,16 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 
 	if (cvp != NULL && cvp->s_data_constant && cvp->s_data_desired)
 		s_data_desired = cvp->s_data_desired;
-	skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15 + s_data_desired, 1, GFP_ATOMIC);
-	if (skb == NULL)
+	skb = alloc_skb(MAX_TCP_HEADER + 15 + s_data_desired,
+			sk_gfp_atomic(sk, GFP_ATOMIC));
+	if (unlikely(!skb)) {
+		dst_release(dst);
 		return NULL;
-
+	}
 	/* Reserve space for headers. */
 	skb_reserve(skb, MAX_TCP_HEADER);
 
-	skb_dst_set(skb, dst_clone(dst));
+	skb_dst_set(skb, dst);
 
 	mss = dst_metric_advmss(dst);
 	if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss)
@@ -2645,6 +2853,109 @@ void tcp_connect_init(struct sock *sk)
 	tcp_clear_retrans(tp);
 }
 
+static void tcp_connect_queue_skb(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
+
+	tcb->end_seq += skb->len;
+	skb_header_release(skb);
+	__tcp_add_write_queue_tail(sk, skb);
+	sk->sk_wmem_queued += skb->truesize;
+	sk_mem_charge(sk, skb->truesize);
+	tp->write_seq = tcb->end_seq;
+	tp->packets_out += tcp_skb_pcount(skb);
+}
+
+/* Build and send a SYN with data and (cached) Fast Open cookie. However,
+ * queue a data-only packet after the regular SYN, such that regular SYNs
+ * are retransmitted on timeouts. Also if the remote SYN-ACK acknowledges
+ * only the SYN sequence, the data are retransmitted in the first ACK.
+ * If cookie is not cached or other error occurs, falls back to send a
+ * regular SYN with Fast Open cookie request option.
+ */
+static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_fastopen_request *fo = tp->fastopen_req;
+	int syn_loss = 0, space, i, err = 0, iovlen = fo->data->msg_iovlen;
+	struct sk_buff *syn_data = NULL, *data;
+	unsigned long last_syn_loss = 0;
+
+	tp->rx_opt.mss_clamp = tp->advmss;  /* If MSS is not cached */
+	tcp_fastopen_cache_get(sk, &tp->rx_opt.mss_clamp, &fo->cookie,
+			       &syn_loss, &last_syn_loss);
+	/* Recurring FO SYN losses: revert to regular handshake temporarily */
+	if (syn_loss > 1 &&
+	    time_before(jiffies, last_syn_loss + (60*HZ << syn_loss))) {
+		fo->cookie.len = -1;
+		goto fallback;
+	}
+
+	if (sysctl_tcp_fastopen & TFO_CLIENT_NO_COOKIE)
+		fo->cookie.len = -1;
+	else if (fo->cookie.len <= 0)
+		goto fallback;
+
+	/* MSS for SYN-data is based on cached MSS and bounded by PMTU and
+	 * user-MSS. Reserve maximum option space for middleboxes that add
+	 * private TCP options. The cost is reduced data space in SYN :(
+	 */
+	if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < tp->rx_opt.mss_clamp)
+		tp->rx_opt.mss_clamp = tp->rx_opt.user_mss;
+	space = tcp_mtu_to_mss(sk, inet_csk(sk)->icsk_pmtu_cookie) -
+		MAX_TCP_OPTION_SPACE;
+
+	syn_data = skb_copy_expand(syn, skb_headroom(syn), space,
+				   sk->sk_allocation);
+	if (syn_data == NULL)
+		goto fallback;
+
+	for (i = 0; i < iovlen && syn_data->len < space; ++i) {
+		struct iovec *iov = &fo->data->msg_iov[i];
+		unsigned char __user *from = iov->iov_base;
+		int len = iov->iov_len;
+
+		if (syn_data->len + len > space)
+			len = space - syn_data->len;
+		else if (i + 1 == iovlen)
+			/* No more data pending in inet_wait_for_connect() */
+			fo->data = NULL;
+
+		if (skb_add_data(syn_data, from, len))
+			goto fallback;
+	}
+
+	/* Queue a data-only packet after the regular SYN for retransmission */
+	data = pskb_copy(syn_data, sk->sk_allocation);
+	if (data == NULL)
+		goto fallback;
+	TCP_SKB_CB(data)->seq++;
+	TCP_SKB_CB(data)->tcp_flags &= ~TCPHDR_SYN;
+	TCP_SKB_CB(data)->tcp_flags = (TCPHDR_ACK|TCPHDR_PSH);
+	tcp_connect_queue_skb(sk, data);
+	fo->copied = data->len;
+
+	if (tcp_transmit_skb(sk, syn_data, 0, sk->sk_allocation) == 0) {
+		tp->syn_data = (fo->copied > 0);
+		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFASTOPENACTIVE);
+		goto done;
+	}
+	syn_data = NULL;
+
+fallback:
+	/* Send a regular SYN with Fast Open cookie request option */
+	if (fo->cookie.len > 0)
+		fo->cookie.len = 0;
+	err = tcp_transmit_skb(sk, syn, 1, sk->sk_allocation);
+	if (err)
+		tp->syn_fastopen = 0;
+	kfree_skb(syn_data);
+done:
+	fo->cookie.len = -1;  /* Exclude Fast Open option for SYN retries */
+	return err;
+}
+
 /* Build a SYN and send it off. */
 int tcp_connect(struct sock *sk)
 {
@@ -2662,17 +2973,13 @@ int tcp_connect(struct sock *sk)
 	skb_reserve(buff, MAX_TCP_HEADER);
 
 	tcp_init_nondata_skb(buff, tp->write_seq++, TCPHDR_SYN);
+	tp->retrans_stamp = TCP_SKB_CB(buff)->when = tcp_time_stamp;
+	tcp_connect_queue_skb(sk, buff);
 	TCP_ECN_send_syn(sk, buff);
 
-	/* Send it off. */
-	TCP_SKB_CB(buff)->when = tcp_time_stamp;
-	tp->retrans_stamp = TCP_SKB_CB(buff)->when;
-	skb_header_release(buff);
-	__tcp_add_write_queue_tail(sk, buff);
-	sk->sk_wmem_queued += buff->truesize;
-	sk_mem_charge(sk, buff->truesize);
-	tp->packets_out += tcp_skb_pcount(buff);
-	err = tcp_transmit_skb(sk, buff, 1, sk->sk_allocation);
+	/* Send off SYN; include data in Fast Open. */
+	err = tp->fastopen_req ? tcp_send_syn_data(sk, buff) :
+	      tcp_transmit_skb(sk, buff, 1, sk->sk_allocation);
 	if (err == -ECONNREFUSED)
 		return err;
 
@@ -2759,7 +3066,7 @@ void tcp_send_ack(struct sock *sk)
 	 * tcp_transmit_skb() will set the ownership to this
 	 * sock.
 	 */
-	buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
+	buff = alloc_skb(MAX_TCP_HEADER, sk_gfp_atomic(sk, GFP_ATOMIC));
 	if (buff == NULL) {
 		inet_csk_schedule_ack(sk);
 		inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN;
@@ -2774,7 +3081,7 @@ void tcp_send_ack(struct sock *sk)
 
 	/* Send it off, this clears delayed acks for us. */
 	TCP_SKB_CB(buff)->when = tcp_time_stamp;
-	tcp_transmit_skb(sk, buff, 0, GFP_ATOMIC);
+	tcp_transmit_skb(sk, buff, 0, sk_gfp_atomic(sk, GFP_ATOMIC));
 }
 
 /* This routine sends a packet with an out of date sequence
@@ -2794,7 +3101,7 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent)
 	struct sk_buff *skb;
 
 	/* We don't queue it, tcp_transmit_skb() sets ownership. */
-	skb = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
+	skb = alloc_skb(MAX_TCP_HEADER, sk_gfp_atomic(sk, GFP_ATOMIC));
 	if (skb == NULL)
 		return -1;