[PROTON-2321] Add benchmark for pn_data_t initialization (PROTON-2229)

• Type: Test
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: proton-c-0.33.0
• Fix Version/s: proton-c-0.35.0
• Component/s: proton-c
• Assignee: Jiri Daněk
• Reporter: Jiri Daněk
• Created: 14/Jan/21 15:28
• Updated: 02/Jul/21 15:10
• Resolved: 22/Jun/21 13:38

Description

-----------------------------------------------------------------------------------
Benchmark                                         Time             CPU   Iterations
-----------------------------------------------------------------------------------

// size_t size = bytes->size + 0;
BM_Encode10MbMessage/put_binary count:1        71.7 ms         70.4 ms           10
BM_Encode10MbMessage/put_binary count:10        239 ms          205 ms            3

// size_t size = bytes->size + 1;
BM_Encode10MbMessage/put_binary count:1        1.25 ms        0.874 ms          744
BM_Encode10MbMessage/put_binary count:10       1059 ms         1045 ms            1

// size_t size = bytes->size + 2;
BM_Encode10MbMessage/put_binary count:1        1.22 ms        0.916 ms          634
BM_Encode10MbMessage/put_binary count:10        178 ms          135 ms            5

// size_t size = pn_max(bytes->size+1, PNI_INTERN_MINSIZE);
BM_Encode10MbMessage/put_binary count:1       0.941 ms        0.815 ms          783
BM_Encode10MbMessage/put_binary count:10       1390 ms         1187 ms            1

// size_t size = pn_max(bytes->size+2, PNI_INTERN_MINSIZE);
BM_Encode10MbMessage/put_binary count:1       0.922 ms        0.811 ms          718
BM_Encode10MbMessage/put_binary count:10        184 ms          144 ms            5

The above shows that + 1 improves things significantly, but there is a scenario where + 2 is even better.

static int pni_data_intern_node(pn_data_t *data, pni_node_t *node)
{
  pn_bytes_t *bytes = pni_data_bytes(data, node);
  if (!bytes) return 0;
  if (data->buf == NULL) {
    // Heuristic to avoid growing small buffers too much
    // size + 1 to allow for zero termination
    size_t size = pn_max(bytes->size+1, PNI_INTERN_MINSIZE);
   ...

Issue Links

• depends upon: PROTON-2353 Client becomes cpu bound in pn_buffer_rotate() on session flow control
• depends upon: PROTON-2229 pn_data_t initialization lead to low performance