From 0d57d93a06727943dbad0bc80768a29d74ce22a0 Mon Sep 17 00:00:00 2001 From: Andrew Kryczka Date: Tue, 2 Jul 2019 12:03:40 -0700 Subject: [PATCH] Support jemalloc compiled with `--with-jemalloc-prefix` (#5521) 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 --- db/malloc_stats.cc | 4 ---- port/jemalloc_helper.h | 1 + 2 files changed, 1 insertion(+), 4 deletions(-) diff --git a/db/malloc_stats.cc b/db/malloc_stats.cc index bcee5c3fb..1dfe0d55b 100644 --- a/db/malloc_stats.cc +++ b/db/malloc_stats.cc @@ -20,10 +20,6 @@ namespace rocksdb { #ifdef ROCKSDB_JEMALLOC -#ifdef JEMALLOC_NO_RENAME -#define malloc_stats_print je_malloc_stats_print -#endif - typedef struct { char* cur; char* end; diff --git a/port/jemalloc_helper.h b/port/jemalloc_helper.h index 26e5fb663..6aeb780ee 100644 --- a/port/jemalloc_helper.h +++ b/port/jemalloc_helper.h @@ -9,6 +9,7 @@ #ifdef __FreeBSD__ #include #else +#define JEMALLOC_MANGLE #include #endif