-
Type: Improvement
-
Resolution: Fixed
-
Priority: Major - P3
-
Affects Version/s: None
-
Component/s: Diagnostics, Internal Code
-
Fully Compatible
-
v3.4, v3.2
-
Platforms 2017-11-13
From time to time tcmalloc acquires memory from the system using mmap, and returns it to the system using madvise. These can be expensive operations, and they hold a lock so they can create a bottleneck. There aren't adequate metrics to diagnose issues related to this, and to assess the effect of making changes such as enabling TCMALLOC_AGGRESSIVE_DECOMMIT. The following could be helpful:
- number of mmap operations to acquire memory
- number of bytes acquired
- cumulative time spent in such operations
- number of madvise oeprations to release memory
- number of bytes released
- cumulative time spent in such operations
- number of bytes allocated using decommitted memory (which kernel then must re-commit)
- is related to
-
SERVER-31417 Improve tcmalloc when decommitting large amounts of memory
- Backlog