From 7f8e758031c69f8ea02ae107a2ce8f35881c96c2 Mon Sep 17 00:00:00 2001
From: Stephan Bauroth <s.bauroth@tu-berlin.de>
Date: Thu, 5 Nov 2026 13:40:07 +0000
Subject: [PATCH] rocksdb: use posix_memalign for cache shards on musl

---
 build-bench-env.sh                    |  5 +++++
 patches/rocksdb_cacheline_alloc.patch | 11 +++++++++++
 2 files changed, 16 insertions(+)
 create mode 100644 patches/rocksdb_cacheline_alloc.patch

diff --git a/build-bench-env.sh b/build-bench-env.sh
index d4c4a7a..c4cb0ba 100755
--- a/build-bench-env.sh
+++ b/build-bench-env.sh
@@ -856,6 +856,11 @@ if test "$setup_rocksdb" = "1"; then
   fi
 
   cd "rocksdb-$version_rocksdb"
+  # musl defines neither _POSIX_C_SOURCE nor _XOPEN_SOURCE by default, so
+  # without this rocksdb allocates its cache shards with plain malloc
+  set +e
+  patch -p1 -N -r- < ../../patches/rocksdb_cacheline_alloc.patch
+  set -e
   DISABLE_WARNING_AS_ERROR=1 DISABLE_JEMALLOC=1 ROCKSDB_DISABLE_TCMALLOC=1 make db_bench -j $procs
   [ "$CI" ] && find . -name '*.o' -delete
   popd
diff --git a/patches/rocksdb_cacheline_alloc.patch b/patches/rocksdb_cacheline_alloc.patch
new file mode 100644
index 0000000..850fc3d
--- /dev/null
+++ b/patches/rocksdb_cacheline_alloc.patch
@@ -0,0 +1,11 @@
+--- a/port/port_posix.cc
++++ b/port/port_posix.cc
+@@ -228,7 +228,7 @@
+ void* cacheline_aligned_alloc(size_t size) {
+ #if __GNUC__ < 5 && defined(__SANITIZE_ADDRESS__)
+   return malloc(size);
+-#elif (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600 || defined(__APPLE__))
++#elif (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600 || defined(__APPLE__) || defined(__linux__))
+   void* m;
+   errno = posix_memalign(&m, CACHE_LINE_SIZE, size);
+   return errno ? nullptr : m;