[PROTON-2229] pn_data_t initialization lead to low performance

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: proton-c-0.30.0
• Fix Version/s: proton-c-0.33.0
• Component/s: proton-c
• Labels: initialization perf
• Environment: x86_64 GNU/Linux
• Flags: Patch, Important
• Assignee: Andrew Stitcher
• Reporter: wanfa deng
• Created: 27/May/20 07:34
• Updated: 19/Apr/21 20:32
• Resolved: 21/Oct/20 19:16

Description

Recently I update qpid-proton from 0.28.0 to 0.30.0 version, and find massive produce performance fallen by 80%。

Finally，I find this is caused by pn_data_t initialization。 In 0.28.0 version, it's like 
data->buf = pn_buffer(64);
and in In 0.30.0 version, it's like 
data->buf = NULL;
 
And when data->buf is initialized by NULL,  in the following call flow, 
pn_data_put_binary->pni_data_intern_node->pn_buffer_memory->pn_buffer_defrag->pn_buffer_rotate, 
buf->start is more likely not equal to 0, this is leading to buffer rotate, and make the performance lower.

Issue Links

• is depended upon by: PROTON-2321 Add benchmark for pn_data_t initialization (PROTON-2229)