QueryMemoryInfo and svc GetInfo 7/22 counted only the program and heap as
used, so the game (free = total - used) kept mapping pages outside the heap:
7.9 GB by Kokiri Forest. Used memory now adds the pages mapped through
AllocateMemoryPages (HOS_MEMINFO_OLD=1 restores the old report).

- Windows: SetMemoryHeapSize no longer commits the heap up front
  (HOS_HEAP_COMMIT=1 restores it); commit_on_touch continues when another
  thread already committed the page (first-touch race), and nn_fs commits
  guest buffers before ReadFile/WriteFile.
- vk_memory: RX_VK_IMPORT_HIGH defaults to 85 on Windows; pools evicted in
  GRACE mode leave the budget at once and are freed after RX_VK_RETIRE_SECS.

Measured on Windows/NVIDIA in play: mapped pages ~2.6 GB (was 7.9 GB),
working set ~13.9 GB (was ~20 GB), no crash. Untested on AMD/Intel and
in sessions over 30 minutes.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

@@ -3429,1 +3435,4 @@
+    // after a wait there (retired_mode GRACE) without them, so the pools this valve takes wait the same way: held, the table
+    // already off them, until RX_VK_RETIRE_SECS (30) have passed since, and only then queued for the GPU (retired_value). What
+    // waits is counted as given back, so the valve does not take more for the same bytes. RX_VK_IMPORT_HIGH=0: off, as before
     static const int high = std::clamp(env_int("RX_VK_IMPORT_HIGH", 85), 0, 100);

@@ -242,0 +247,4 @@
+#if defined(_WIN32)
+    static int commit_all = -1;
+    if (commit_all < 0) commit_all = env_on("HOS_HEAP_COMMIT");
+    if (size > hos_heap_size && commit_all) hos_commit(HOS_HEAP_BASE + hos_heap_size, size - hos_heap_size);

@@ -280,0 +294,4 @@
+   memory resident, a working set of 19.6 GB, against the console's 12 GB in all). One bit a 4 KB page of the guest window,
+   so that pages mapped twice or freed twice count once. HOS_PAGES_LIMIT=1: past the console's total (heap + pages),
+   AllocateMemoryPages fails as it would there; unset, only counted and logged */
+static uint64_t mapped_bits[(HOS_GUEST_SPACE >> 12) / 64];

@@ -280,0 +328,4 @@
+    LOCK();
+    const uint64_t mapped = mapped_bytes;
+    UNLOCK();
+    return base + hos_heap_size + mapped;

@@ -88,0 +87,4 @@
+    if (!VirtualQuery(p, &mbi, sizeof mbi)) return EXCEPTION_CONTINUE_SEARCH;
+    /* (another thread committed this 64 KB between the fault and the look: the access is tried again. The heap is committed on
+       touch now (hos_mem.c), and two threads touching one new chunk at once crashed the second in the boot's module loads) */
+    if (mbi.State == MEM_COMMIT && mbi.Protect == PAGE_READWRITE) return EXCEPTION_CONTINUE_EXECUTION;

@@ -420,1 +420,4 @@
     const int away = hos_vcore_away();   /* (as OpenFile: no core held through the read) */
+    /* (the kernel's ReadFile does not fault pages in: a heap page nothing touched yet (hos_mem.c, committed on touch) is
+       committed for it first, or the read fails with ERROR_NOACCESS) */
+    if (size && hos_guest_range(buf, size)) hos_commit(buf, size);

@@ -88,0 +91,4 @@
+    /* (another thread committed this 64 KB between the fault and the look: the access is tried again. The heap is committed on
+       touch now (hos_mem.c), and two threads touching one new chunk at once crashed the second in the boot's module loads.
+       Not an execute fault (8, DEP): a jump into guest memory would fault again at once, forever; it goes on to the crash report) */
+    if (mbi.State == MEM_COMMIT && mbi.Protect == PAGE_READWRITE && rec->ExceptionInformation[0] != 8)

@@ -87,6 +87,7 @@ const char *hos_romfs_dir, *hos_user_dir;
 #define R_PATH_EXISTS 0x402             /* fs::ResultPathAlreadyExists */
 #define R_NOT_MOUNTED 0xCA02            /* fs::ResultInvalidMountName-ish: no such mount */
 #define R_TARGET_NOT_FOUND 0x7D402      /* fs::ResultTargetNotFound (save data) */
+#define R_OUT_OF_MEMORY 0xCA01          /* svc::ResultOutOfMemory: the guest buffer could not be committed (Windows) */