[TS-2122] Enlarge the 64KB limitation of log buffer size

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.1.2
• Component/s: Logging
• Assignee: Yunkai Zhang
• Reporter: Yunkai Zhang
• Created: 09/Aug/13 02:49
• Updated: 05/Dec/13 23:51
• Resolved: 09/Aug/13 06:39

Description

The Logging module use uint16_t(LogBuffer->m_state.s.m_offset/byte_count) to store log buffer size:

  struct
  {
    uint16_t offset;              // buffer should be <= 64KB
    uint16_t num_entries;         // number of entries in buffer
    uint16_t byte_count;          // bytes in buffer
    uint16_t full:1;              // not accepting more checkouts
    uint16_t num_writers:15;      // number of writers
  } s;

It's very dangerous for user, as there are not any warning when user breaks the limitation.

In our environment, we set the log_buffer_size to 512KB(and set max_entries_per_buffer to 1000), it make ATS crashing.

I'll give a patch to enlarge this limitation from 64KB to 4GB by merging offset and byte_count variables into one, so that we can use uint32_t to store the buffer size.