Set the default memprof serialization format as binary. 9 tests are
updated to use print_text=true. Also fixed an issue with concatenation
of default and test specified options (missing separator).
Differential Revision: https://reviews.llvm.org/D113617
This change implements the raw binary format discussed in
https://lists.llvm.org/pipermail/llvm-dev/2021-September/153007.html
Summary of changes
* Add a new memprof option to choose binary or text (default) format.
* Add a rawprofile library which serializes the MIB map to profile.
* Add a unit test for rawprofile.
* Mark sanitizer procmaps methods as virtual to be able to mock them.
* Extend memprof_profile_dump regression test.
Differential Revision: https://reviews.llvm.org/D113317
The existing implementation uses a cache + eviction based scheme to
record heap profile information. This design was adopted to ensure a
constant memory overhead (due to fixed number of cache entries) along
with incremental write-to-disk for evictions. We find that since the
number to entries to track is O(unique-allocation-contexts) the overhead
of keeping all contexts in memory is not very high. On a clang workload,
the max number of unique allocation contexts was ~35K, median ~11K.
For each context, we (currently) store 64 bytes of data - this amounts
to 5.5MB (max). Given the low overheads for a complex workload, we can
simplify the implementation by using a hashmap without eviction.
Other changes:
* Memory map is dumped at the end rather than startup. The relative
order in the profile dump is unchanged since we no longer have evicted
entries at runtime.
* Added a test to check meminfoblocks are merged.
Differential Revision: https://reviews.llvm.org/D111676
See RFC for background:
http://lists.llvm.org/pipermail/llvm-dev/2020-June/142744.html
Follow on companion to the clang/llvm instrumentation support in D85948
and committed earlier.
This patch adds the compiler-rt runtime support for the memory
profiling.
Note that much of this support was cloned from asan (and then greatly
simplified and renamed). For example the interactions with the
sanitizer_common allocators, error handling, interception, etc.
The bulk of the memory profiling specific code can be found in the
MemInfoBlock, MemInfoBlockCache, and related classes defined and used
in memprof_allocator.cpp.
For now, the memory profile is dumped to text (stderr by default, but
honors the sanitizer_common log_path flag). It is dumped in either a
default verbose format, or an optional terse format.
This patch also adds a set of tests for the core functionality.
Differential Revision: https://reviews.llvm.org/D87120
Snehasish Kumar