Summary:
Previously, if the jemalloc was built with nonempty string for
`--with-jemalloc-prefix`, then `HasJemalloc()` would return false on
Linux, so jemalloc would not be used at runtime. On Mac, it would cause
a linker failure due to no definitions found for the weak functions
declared in "port/jemalloc_helper.h". This should be a rare problem
because (1) on Linux the default `--with-jemalloc-prefix` value is the
empty string, and (2) Homebrew's build explicitly sets
`--with-jemalloc-prefix` to the empty string.
However, there are cases where `--with-jemalloc-prefix` is nonempty.
For example, when building jemalloc from source on Mac, the default
setting is `--with-jemalloc-prefix=je_`. Such jemalloc builds should be
usable by RocksDB.
The fix is simple. Defining `JEMALLOC_MANGLE` before including
"jemalloc.h" causes it to define unprefixed symbols that are aliases for
each of the prefixed symbols. Thanks to benesch for figuring this out
and explaining it to me.
Fixes https://github.com/facebook/rocksdb/issues/1462.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5521
Test Plan:
build jemalloc with prefixed symbols:
```
$ ./configure --with-jemalloc-prefix=lol
$ make
```
compile rocksdb against it:
```
$ WITH_JEMALLOC_FLAG=1 JEMALLOC=1 EXTRA_LDFLAGS="-L/home/andrew/jemalloc/lib/" EXTRA_CXXFLAGS="-I/home/andrew/jemalloc/include/" make -j12 ./db_bench
```
run db_bench and verify jemalloc actually used:
```
$ ./db_bench -benchmarks=fillrandom -statistics=true -dump_malloc_stats=true -stats_dump_period_sec=1
$ grep jemalloc /tmp/rocksdbtest-1000/dbbench/LOG
2019/06/29-12:20:52.088658 7fc5fb7f6700 [_impl/db_impl.cc:837] ___ Begin jemalloc statistics ___
...
```
Differential Revision: D16092758
fbshipit-source-id: c2c358346190ed62ceb2a3547a6c4c180b12f7c4
Summary:
"__attribute__((__weak__))" was introduced in port\jemalloc_helper.h. It's not supported by Microsoft VS 2015, resulting in compile error. This fix adds a #if branch to work around the compile issue.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5458
Differential Revision: D15827285
fbshipit-source-id: 8c5f7ad31de1ac677bd96f16c4450767de834beb
Summary:
JEMALLOC_CXX_THROW is not defined for earlier versions of jemalloc (e.g. 3.6), causing builds to fail on some platforms. Fixing it. Closes#4869
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5053
Differential Revision: D14390034
Pulled By: sagar0
fbshipit-source-id: b2b7a03cd377201ef385eb521f65bae85c558055
Summary:
Declare Jemalloc non-standard APIs as weak symbols, so that if Jemalloc is linked with the binary, these symbols will be replaced by Jemalloc's, otherwise they will be nullptr. This is similar to how folly detect jemalloc, but we assume the main program use jemalloc as long as jemalloc is linked: https://github.com/facebook/folly/blob/master/folly/memory/Malloc.h#L147
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4844
Differential Revision: D13574934
Pulled By: yiwu-arbug
fbshipit-source-id: 7ea871beb1be7d5a1259cc38f9b78078793db2db
