perf: simple walredo bench (#2816)

adds a simple walredo bench to allow some comparison of the walredo
throughput.

Cc: #1339, #2778

pageserver/Cargo.toml

@@ -76,3 +76,7 @@ tempfile = "3.2"
 [[bench]]
 name = "bench_layer_map"
 harness = false
+
+[[bench]]
+name = "bench_walredo"
+harness = false

pageserver/src/config.rs

@@ -614,8 +614,9 @@ impl PageServerConf {
         PathBuf::from(format!("../tmp_check/test_{test_name}"))
     }
 
-    #[cfg(test)]
     pub fn dummy_conf(repo_dir: PathBuf) -> Self {
+        let pg_distrib_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("../pg_install");
+
         PageServerConf {
             id: NodeId(0),
             wait_lsn_timeout: Duration::from_secs(60),
@@ -626,7 +627,7 @@ impl PageServerConf {
             listen_http_addr: defaults::DEFAULT_HTTP_LISTEN_ADDR.to_string(),
             superuser: "cloud_admin".to_string(),
             workdir: repo_dir,
-            pg_distrib_dir: PathBuf::new(),
+            pg_distrib_dir,
             auth_type: AuthType::Trust,
             auth_validation_public_key_path: None,
             remote_storage_config: None,

pageserver/src/tenant_config.rs

@@ -216,7 +216,6 @@ impl TenantConf {
         }
     }
 
-    #[cfg(test)]
     pub fn dummy_conf() -> Self {
         TenantConf {
             checkpoint_distance: defaults::DEFAULT_CHECKPOINT_DISTANCE,

pageserver/src/walredo.rs

@@ -210,6 +210,16 @@ impl PostgresRedoManager {
         }
     }
 
+    /// Launch process pre-emptively. Should not be needed except for benchmarking.
+    pub fn launch_process(&mut self, pg_version: u32) -> anyhow::Result<()> {
+        let inner = self.process.get_mut().unwrap();
+        if inner.is_none() {
+            let p = PostgresRedoProcess::launch(self.conf, self.tenant_id, pg_version)?;
+            *inner = Some(p);
+        }
+        Ok(())
+    }
+
     ///
     /// Process one request for WAL redo using wal-redo postgres
     ///