There are some holes in the event definitions, spaces are wasted. Based
on the analysis result of pahole and event format files, 22 events have
more than one hole. To change less and fix worst, 5 events are picked
up and fixed in this patch according the following rules.

Rules:

  - try not to affect reading habit and understanding of the fields;
  - can be completely fixed (all holes are removed);

NOTES:

  - changing the order of event fields breaks API compatibility,
    programs should parse and determine the real data order, instead of
    hard-coded the order of fields;
  - reduce holes as much as possible when adding / modifying;

Summary (#event_name #before -> #after):

 1. net_dev_start_xmit
    5 holes (10 bytes) -> 0

 2. net_dev_rx_verbose_template
    6 holes (17 bytes) -> 0

 3. tcp_probe
    3 holes (8 bytes) -> 0

 4. qdisc_dequeue
    2 holes (8 bytes) -> 0

 5. rpc_xdr_alignment
    2 holes (8 bytes) -> 0

Link: https://www.spinics.net/lists/netdev/msg726308.html
Link: https://www.spinics.net/lists/netdev/msg726451.html
Cc: David Miller <da...@davemloft.net>
Cc: Eric Dumazet <eduma...@google.com>
Cc: Steven Rostedt <rost...@goodmis.org>
Cc: Ingo Molnar <mi...@redhat.com>
Suggested-by: Steven Rostedt <rost...@goodmis.org>
Signed-off-by: Tony Lu <ton...@linux.alibaba.com>
---
 include/trace/events/net.h    | 42 +++++++++++++++++------------------
 include/trace/events/qdisc.h  |  4 ++--
 include/trace/events/sunrpc.h |  4 ++--
 include/trace/events/tcp.h    |  2 +-
 4 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/include/trace/events/net.h b/include/trace/events/net.h
index 2399073c3afc..b1db7ab88d4b 100644
--- a/include/trace/events/net.h
+++ b/include/trace/events/net.h
@@ -20,18 +20,18 @@ TRACE_EVENT(net_dev_start_xmit,
        TP_STRUCT__entry(
                __string(       name,                   dev->name       )
                __field(        u16,                    queue_mapping   )
+               __field(        u16,                    protocol        )
                __field(        const void *,           skbaddr         )
+               __field(        u8,                     ip_summed       )
                __field(        bool,                   vlan_tagged     )
                __field(        u16,                    vlan_proto      )
                __field(        u16,                    vlan_tci        )
-               __field(        u16,                    protocol        )
-               __field(        u8,                     ip_summed       )
+               __field(        bool,                   transport_offset_valid)
+               __field(        u8,                     tx_flags        )
                __field(        unsigned int,           len             )
                __field(        unsigned int,           data_len        )
                __field(        int,                    network_offset  )
-               __field(        bool,                   transport_offset_valid)
                __field(        int,                    transport_offset)
-               __field(        u8,                     tx_flags        )
                __field(        u16,                    gso_size        )
                __field(        u16,                    gso_segs        )
                __field(        u16,                    gso_type        )
@@ -40,19 +40,19 @@ TRACE_EVENT(net_dev_start_xmit,
        TP_fast_assign(
                __assign_str(name, dev->name);
                __entry->queue_mapping = skb->queue_mapping;
+               __entry->protocol = ntohs(skb->protocol);
                __entry->skbaddr = skb;
+               __entry->ip_summed = skb->ip_summed;
                __entry->vlan_tagged = skb_vlan_tag_present(skb);
                __entry->vlan_proto = ntohs(skb->vlan_proto);
                __entry->vlan_tci = skb_vlan_tag_get(skb);
-               __entry->protocol = ntohs(skb->protocol);
-               __entry->ip_summed = skb->ip_summed;
+               __entry->transport_offset_valid =
+                       skb_transport_header_was_set(skb);
+               __entry->tx_flags = skb_shinfo(skb)->tx_flags;
                __entry->len = skb->len;
                __entry->data_len = skb->data_len;
                __entry->network_offset = skb_network_offset(skb);
-               __entry->transport_offset_valid =
-                       skb_transport_header_was_set(skb);
                __entry->transport_offset = skb_transport_offset(skb);
-               __entry->tx_flags = skb_shinfo(skb)->tx_flags;
                __entry->gso_size = skb_shinfo(skb)->gso_size;
                __entry->gso_segs = skb_shinfo(skb)->gso_segs;
                __entry->gso_type = skb_shinfo(skb)->gso_type;
@@ -170,23 +170,23 @@ DECLARE_EVENT_CLASS(net_dev_rx_verbose_template,
        TP_STRUCT__entry(
                __string(       name,                   skb->dev->name  )
                __field(        unsigned int,           napi_id         )
-               __field(        u16,                    queue_mapping   )
                __field(        const void *,           skbaddr         )
+               __field(        u16,                    queue_mapping   )
+               __field(        u8,                     ip_summed       )
                __field(        bool,                   vlan_tagged     )
                __field(        u16,                    vlan_proto      )
                __field(        u16,                    vlan_tci        )
                __field(        u16,                    protocol        )
-               __field(        u8,                     ip_summed       )
-               __field(        u32,                    hash            )
                __field(        bool,                   l4_hash         )
+               __field(        bool,                   mac_header_valid)
+               __field(        int,                    mac_header      )
                __field(        unsigned int,           len             )
                __field(        unsigned int,           data_len        )
                __field(        unsigned int,           truesize        )
-               __field(        bool,                   mac_header_valid)
-               __field(        int,                    mac_header      )
-               __field(        unsigned char,          nr_frags        )
+               __field(        u32,                    hash            )
                __field(        u16,                    gso_size        )
                __field(        u16,                    gso_type        )
+               __field(        unsigned char,          nr_frags        )
        ),
 
        TP_fast_assign(
@@ -196,23 +196,23 @@ DECLARE_EVENT_CLASS(net_dev_rx_verbose_template,
 #else
                __entry->napi_id = 0;
 #endif
-               __entry->queue_mapping = skb->queue_mapping;
                __entry->skbaddr = skb;
+               __entry->queue_mapping = skb->queue_mapping;
+               __entry->ip_summed = skb->ip_summed;
                __entry->vlan_tagged = skb_vlan_tag_present(skb);
                __entry->vlan_proto = ntohs(skb->vlan_proto);
                __entry->vlan_tci = skb_vlan_tag_get(skb);
                __entry->protocol = ntohs(skb->protocol);
-               __entry->ip_summed = skb->ip_summed;
-               __entry->hash = skb->hash;
                __entry->l4_hash = skb->l4_hash;
+               __entry->mac_header_valid = skb_mac_header_was_set(skb);
+               __entry->mac_header = skb_mac_header(skb) - skb->data;
                __entry->len = skb->len;
                __entry->data_len = skb->data_len;
                __entry->truesize = skb->truesize;
-               __entry->mac_header_valid = skb_mac_header_was_set(skb);
-               __entry->mac_header = skb_mac_header(skb) - skb->data;
-               __entry->nr_frags = skb_shinfo(skb)->nr_frags;
+               __entry->hash = skb->hash;
                __entry->gso_size = skb_shinfo(skb)->gso_size;
                __entry->gso_type = skb_shinfo(skb)->gso_type;
+               __entry->nr_frags = skb_shinfo(skb)->nr_frags;
        ),
 
        TP_printk("dev=%s napi_id=%#x queue_mapping=%u skbaddr=%p 
vlan_tagged=%d vlan_proto=0x%04x vlan_tci=0x%04x protocol=0x%04x ip_summed=%d 
hash=0x%08x l4_hash=%d len=%u data_len=%u truesize=%u mac_header_valid=%d 
mac_header=%d nr_frags=%d gso_size=%d gso_type=%#x",
diff --git a/include/trace/events/qdisc.h b/include/trace/events/qdisc.h
index 330d32d84485..9e7d00256785 100644
--- a/include/trace/events/qdisc.h
+++ b/include/trace/events/qdisc.h
@@ -22,8 +22,8 @@ TRACE_EVENT(qdisc_dequeue,
                __field(        struct Qdisc *,         qdisc   )
                __field(const   struct netdev_queue *,  txq     )
                __field(        int,                    packets )
-               __field(        void *,                 skbaddr )
                __field(        int,                    ifindex )
+               __field(        void *,                 skbaddr )
                __field(        u32,                    handle  )
                __field(        u32,                    parent  )
                __field(        unsigned long,          txq_state)
@@ -34,8 +34,8 @@ TRACE_EVENT(qdisc_dequeue,
                __entry->qdisc          = qdisc;
                __entry->txq            = txq;
                __entry->packets        = skb ? packets : 0;
-               __entry->skbaddr        = skb;
                __entry->ifindex        = txq->dev ? txq->dev->ifindex : 0;
+               __entry->skbaddr        = skb;
                __entry->handle         = qdisc->handle;
                __entry->parent         = qdisc->parent;
                __entry->txq_state      = txq->state;
diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 036eb1f5c133..39f4fdcf4d0f 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -715,8 +715,8 @@ TRACE_EVENT(rpc_xdr_alignment,
                __field(unsigned int, task_id)
                __field(unsigned int, client_id)
                __field(int, version)
-               __field(size_t, offset)
                __field(unsigned int, copied)
+               __field(size_t, offset)
                __field(const void *, head_base)
                __field(size_t, head_len)
                __field(const void *, tail_base)
@@ -739,8 +739,8 @@ TRACE_EVENT(rpc_xdr_alignment,
                __entry->version = task->tk_client->cl_vers;
                __assign_str(procedure, task->tk_msg.rpc_proc->p_name)
 
-               __entry->offset = offset;
                __entry->copied = copied;
+               __entry->offset = offset;
                __entry->head_base = xdr->buf->head[0].iov_base,
                __entry->head_len = xdr->buf->head[0].iov_len,
                __entry->page_len = xdr->buf->page_len,
diff --git a/include/trace/events/tcp.h b/include/trace/events/tcp.h
index ba94857eea11..831abc267373 100644
--- a/include/trace/events/tcp.h
+++ b/include/trace/events/tcp.h
@@ -248,8 +248,8 @@ TRACE_EVENT(tcp_probe,
                __field(__u16, sport)
                __field(__u16, dport)
                __field(__u16, family)
-               __field(__u32, mark)
                __field(__u16, data_len)
+               __field(__u32, mark)
                __field(__u32, snd_nxt)
                __field(__u32, snd_una)
                __field(__u32, snd_cwnd)
-- 
2.19.1.6.gb485710b

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