fix: reduce heap to 2.25 GiB and re-enable initrd mapping on restore

Signed-off-by: danbugs <danilochiarlone@gmail.com>

Author: danbugs

examples/python-agent-driver/hl_pydriver.c

@@ -259,20 +259,6 @@ static void py_initialize_once(void)
 		"  except Exception as _e:\n"
 		"    sys.stderr.write(f'warn: preload {_mod} failed: {_e}\\n')\n");
 
-	/* Exercise pyarrow's pandas shim so it imports pandas_compat,
-	 * vendored.version, etc. during warmup. Without this, the shim
-	 * lazily imports these on first use, but after snapshot restore
-	 * (without initrd re-mapping) the .py files are zeroed pages. */
-	PyRun_SimpleString(
-		"try:\n"
-		"    import pyarrow.pandas_compat\n"
-		"    import pyarrow.vendored.version\n"
-		"    import pandas as _pd\n"
-		"    _pd.DataFrame({'_': ['x']})\n"
-		"    del _pd\n"
-		"except Exception:\n"
-		"    pass\n");
-
 	/* Monkey-patch zipfile.ZipInfo.__init__ to clamp pre-1980 timestamps.
 	 * Unikraft's ramfs reports epoch-0 (1970) for file mtimes; Python's
 	 * zipfile rejects timestamps before 1980, breaking openpyxl's XLSX

host/src/bin/pydriver_run.rs

@@ -44,7 +44,7 @@ fn main() -> Result<()> {
     let t_evolve = Instant::now();
     let mut sandbox = Sandbox::builder(&kernel)
         .initrd_file(&initrd)
-        .heap_size(5 * 512 * 1024 * 1024)
+        .heap_size(2304 * 1024 * 1024)
         .build()?;
     eprintln!(
         "[timing] evolve={:.1}ms",

host/src/bin/pyhl.rs

@@ -451,7 +451,7 @@ fn cmd_setup(args: SetupArgs) -> Result<()> {
     {
         let mut builder = Sandbox::builder(&dst_kernel)
             .initrd_file(&dst_initrd)
-            .heap_size(5 * 512 * 1024 * 1024);
+            .heap_size(2304 * 1024 * 1024);
         for p in &setup_preopens {
             builder = builder.preopen(p.clone());
         }
@@ -593,13 +593,12 @@ fn cmd_run(args: RunArgs) -> Result<()> {
         listen_ports.is_some(),
     )?;
 
-    // No initrd re-mapping: the snapshot already contains all initrd
-    // pages compacted into its blob with rebuilt page tables.
+    let initrd = home.join(INITRD_FILE);
     let t_load = Instant::now();
     let mut sandbox = Sandbox::from_snapshot_file_configured(
         &snapshot,
         &run_preopens,
-        None,
+        Some(&initrd),
         network.as_ref(),
         listen_ports.as_ref(),
     )?;

host/src/pyhl.rs

@@ -197,7 +197,7 @@ pub fn install(opts: &InstallOptions<'_>) -> Result<InstallReport> {
     {
         let mut builder = Sandbox::builder(&dst_kernel)
             .initrd_file(&dst_initrd)
-            .heap_size(5 * 512 * 1024 * 1024);
+            .heap_size(2304 * 1024 * 1024);
         for p in opts.mounts {
             builder = builder.preopen(p.clone());
         }
@@ -274,12 +274,14 @@ impl Runtime {
                 snap.display()
             );
         }
-        // No initrd re-mapping needed: the snapshot already contains all
-        // initrd pages (the snapshot walker compacts every mapped page,
-        // including file-mapped initrd pages, into the blob and rebuilds
-        // page tables to point at the compacted locations).
-        let sandbox =
-            Sandbox::from_snapshot_file_configured(&snap, mounts, None, network, listen_ports)?;
+        let initrd = home.join(INITRD_FILE);
+        let sandbox = Sandbox::from_snapshot_file_configured(
+            &snap,
+            mounts,
+            Some(&initrd),
+            network,
+            listen_ports,
+        )?;
         Ok(Self {
             sandbox,
             first_run: true,