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>

globals.cpp

@@ -47,5 +47,7 @@ int zfb_support;
 int vendor_packet_support;
 /* enable vendor packet in hsa-runtime*/
 int enable_vendor_packet;
+/* check available system memory before allocation */
+bool check_avail_sysram = false;
 
 size_t max_single_alloc_size = 0;

libhsakmt.h

@@ -45,6 +45,7 @@ extern bool is_svm_api_supported;
 extern int zfb_support;
 extern int vendor_packet_support;
 extern int enable_vendor_packet;
+extern bool check_avail_sysram;
 extern size_t max_single_alloc_size;
 
 #undef HSAKMTAPI

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;

openclose.cpp

@@ -129,6 +129,11 @@ static HSAKMT_STATUS init_vars_from_env(void) {
   if (envvar)
     enable_vendor_packet = atoi(envvar);
 
+  /* Decide whether to check available system memory before allocation */
+  envvar = getenv("WSL_CHECK_AVAIL_SYSRAM");
+  if (envvar)
+    check_avail_sysram = !strcmp(envvar, "1");
+
   return HSAKMT_STATUS_SUCCESS;
 }