Improve memory

server-rs/src/main.rs

@@ -19,6 +19,25 @@ mod routes;
 mod state;
 pub mod utils;
 
+// Use jemalloc as the global allocator. glibc malloc keeps freed memory in many
+// per-CPU arenas and rarely returns it to the OS, so the transient buffers from
+// the rayon/Polars-parallel data load stay resident and inflate steady-state RSS.
+// jemalloc's decay-based purging (configured below) hands those pages back.
+#[cfg(not(target_env = "msvc"))]
+#[global_allocator]
+static GLOBAL: tikv_jemallocator::Jemalloc = tikv_jemallocator::Jemalloc;
+
+// Return dirty/muzzy pages to the OS ~1s after they go idle, and run a background
+// thread to do so proactively (so RSS drops after the startup load peak without
+// waiting for the next allocation). Read by jemalloc at startup via the
+// `malloc_conf` symbol (unprefixed on Linux). Can be overridden by the
+// `_RJEM_MALLOC_CONF` / `MALLOC_CONF` env var.
+#[cfg(not(target_env = "msvc"))]
+#[allow(non_upper_case_globals)]
+#[used]
+#[export_name = "malloc_conf"]
+pub static malloc_conf: &[u8] = b"background_thread:true,dirty_decay_ms:1000,muzzy_decay_ms:1000\0";
+
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 use std::time::Duration;