wsl/hsakmt: Introduce WSL_CHECK_AVAIL_SYSRAM environment variable

By default, this variable is 0. Set it to 1 to compare available
system memory with the requested amount before allocation. It helps
identify system hangs caused by excessive memory allocation.

Signed-off-by: lyndonli <Lyndon.Li@amd.com>
Reviewed-by: Flora Cui <flora.cui@amd.com>
Part-of: <http://10.67.69.192/wsl/libhsakmt/-/merge_requests/32>

memory.cpp

@@ -105,6 +105,13 @@ HSAKMT_STATUS HSAKMTAPI hsaKmtAllocMemory(HSAuint32 PreferredNode,
 
 #define POWER_OF_2(x) ((x && (!(x & (x - 1)))) ? 1 : 0)
 
+bool isSystemMemoryAvailable(HSAuint64 SizeInBytes) {
+  struct sysinfo info;
+  if (sysinfo(&info) != 0)
+    return false;
+  return SizeInBytes <= info.freeram;
+}
+
 HSAKMT_STATUS HSAKMTAPI hsaKmtAllocMemoryAlign(HSAuint32 PreferredNode,
                                                HSAuint64 SizeInBytes,
                                                HSAuint64 Alignment,
@@ -140,6 +147,9 @@ HSAKMT_STATUS HSAKMTAPI hsaKmtAllocMemoryAlign(HSAuint32 PreferredNode,
     if (SizeInBytes > max_single_alloc_size)
       return HSAKMT_STATUS_NO_MEMORY;
 
+    if (check_avail_sysram && !isSystemMemoryAvailable(SizeInBytes))
+      return HSAKMT_STATUS_NO_MEMORY;
+
     /* If allocate VRAM under ZFB mode */
     if (zfb_support && MemFlags.ui32.NonPaged == 1)
       MemFlags.ui32.CoarseGrain = 1;