Allocation Tracking
Goal: To track allocations’s happening during the lifetime of a Ruby process.
Outcomes: When I run a program to completion with allocation tracking
enabled I should present enough data to be able ot produce the following
artifacts:
- a cumulative and non-cumulative time series of all allocations during
the programs lifetime
- a visualisation of the count of allocations of different sizes being made
during the programs lifetime
- a visualisation of the size of allocations originating from each call site
over the lifetime of the program
What do I need In order to acheive the outcomes, I think that, for each
allocation, we need to record:
- the time that the allocation happened
- the size of the allocation in bytes
- from which function did the allocation originate (ie. which function called
calloc,malloc, or realloc)
What are my options?
MallocStackLoggingNoCompact & malloc history
- macOS only
- UI only provides for attaching to a currently running process. There’s no way
of running a consistent reproducible measurement over the lifetime of a
process that terminates
- no timestamps
mtrace
- GNU GCC extension and Linux only
- doesn’t provide timing information, only address, size and caller (stacktrace)
valgrind (massif)
dtrace
[DTrace]
manual instrumentation of a ruby binary
- would allow me to customise the output
- fragile, changes upstream could break the patch
- time consuming to implement
- would upstream consider something like this?