Try to evaluate available OpenCL device memory and use this information instead of total available OpenCL device memory for autotune

docs/changes.txt

@@ -1,5 +1,11 @@
 * changes v4.2.0 -> xxx
 
+##
+## Improvements
+##
+
+- Try to evaluate available OpenCL device memory and use this information instead of total available OpenCL device memory for autotune
+
 * changes v4.1.0 -> v4.2.0
 
 ##

include/types.h

@@ -953,6 +953,7 @@ typedef struct hc_device_param
   u32     device_processors;
   u64     device_maxmem_alloc;
   u64     device_global_mem;
+  u64     device_available_mem;
   u32     device_maxclock_frequency;
   size_t  device_maxworkgroup_size;
   u64     device_local_mem_size;

src/opencl.c

@@ -3225,6 +3225,8 @@ int opencl_ctx_devices_init (hashcat_ctx_t *hashcat_ctx, const int comptime)
 
       device_param->device_global_mem = device_global_mem;
 
+      device_param->device_available_mem = 0;
+
       // device_maxmem_alloc
 
       cl_ulong device_maxmem_alloc;
@@ -4259,6 +4261,57 @@ int opencl_session_begin (hashcat_ctx_t *hashcat_ctx)
 
     if (CL_rc == -1) return -1;
 
+    // OK, so the problem here is the following:
+    // There's just CL_DEVICE_GLOBAL_MEM_SIZE to ask OpenCL about the total memory on the device,
+    // but there's no way to ask for available memory on the device.
+    // In combination, most OpenCL runtimes implementation of clCreateBuffer()
+    // are doing so called lazy memory allocation on the device.
+    // Now, if the user has X11 (or a game or anything that takes a lot of GPU memory)
+    // running on the host we end up with an error type of this:
+    // clEnqueueNDRangeKernel(): CL_MEM_OBJECT_ALLOCATION_FAILURE
+    // The clEnqueueNDRangeKernel() is because of the lazy allocation
+    // The best way to workaround this problem is if we would be able to ask for available memory,
+    // The idea here is to try to evaluate available memory by allocating it till it errors
+
+    #define MAX_ALLOC_CHECKS_CNT  8192
+    #define MAX_ALLOC_CHECKS_SIZE (32 * 1024 * 1024)
+
+    cl_mem *tmp_device = (cl_mem *) hccalloc (MAX_ALLOC_CHECKS_CNT, sizeof (cl_mem));
+
+    char *tmp_host = (char *) hcmalloc (MAX_ALLOC_CHECKS_SIZE);
+
+    int c;
+
+    for (c = 0; c < MAX_ALLOC_CHECKS_CNT; c++)
+    {
+      cl_int CL_err;
+
+      OCL_PTR *ocl = opencl_ctx->ocl;
+
+      tmp_device[c] = ocl->clCreateBuffer (device_param->context, CL_MEM_READ_ONLY, MAX_ALLOC_CHECKS_SIZE, NULL, &CL_err);
+
+      if (CL_err != CL_SUCCESS) break;
+
+      CL_err = ocl->clEnqueueReadBuffer (device_param->command_queue, tmp_device[c], CL_TRUE, 0, MAX_ALLOC_CHECKS_SIZE, tmp_host, 0, NULL, NULL);
+
+      if (CL_err != CL_SUCCESS) break;
+    }
+
+    int r;
+
+    for (r = 0; r < c; r++)
+    {
+      CL_rc = hc_clReleaseMemObject (hashcat_ctx, tmp_device[r]);
+
+      if (CL_rc == -1) return -1;
+    }
+
+    hcfree (tmp_host);
+
+    hcfree (tmp_device);
+
+    device_param->device_available_mem = c * MAX_ALLOC_CHECKS_SIZE;
+
     /**
      * create input buffers on device : calculate size of fixed memory buffers
      */
@@ -4436,7 +4489,7 @@ int opencl_session_begin (hashcat_ctx_t *hashcat_ctx)
           continue;
         }
 
-        if ((size_scrypt + scrypt_extra_space) > device_param->device_global_mem)
+        if ((size_scrypt + scrypt_extra_space) > device_param->device_available_mem)
         {
           if (user_options->quiet == false) event_log_warning (hashcat_ctx, "Increasing total device memory allocatable for --scrypt-tmto %u.", tmto);
 
@@ -6095,7 +6148,7 @@ int opencl_session_begin (hashcat_ctx_t *hashcat_ctx)
 
     #define PWS_SPACE (1024 * 1024 * 1024)
 
-    // sometimes device_global_mem and device_maxmem_alloc reported back from the opencl runtime are a bit inaccurate.
+    // sometimes device_available_mem and device_maxmem_alloc reported back from the opencl runtime are a bit inaccurate.
     // let's add some extra space just to be sure.
 
     #define EXTRA_SPACE (64 * 1024 * 1024)
@@ -6173,7 +6226,7 @@ int opencl_session_begin (hashcat_ctx_t *hashcat_ctx)
         + size_st_salts
         + size_st_esalts;
 
-      if ((size_total + EXTRA_SPACE) > device_param->device_global_mem) memory_limit_hit = 1;
+      if ((size_total + EXTRA_SPACE) > device_param->device_available_mem) memory_limit_hit = 1;
 
       if (memory_limit_hit == 1)
       {