Bug 350228 - Unhandled ioctl 0x6458 (i965/mesa). Patch from austinenglish@gmail.com.

README_MISSING_SYSCALL_OR_IOCTL

@@ -112,6 +112,10 @@ following:
     This should tell you something like  __NR_mysyscallname.
     Copy this entry to include/vki/vki-scnums-$(VG_PLATFORM).h.
 
+    If you can't find the system call in /usr/include, try looking in the
+    strace source code (https://github.com/strace/strace). Some syscalls/ioctls
+    are not defined explicitly, but strace may have already figured it out.
+
 
 2.  Do 'man 2 mysyscallname' to get some idea of what the syscall
     does.  Note that the actual kernel interface can differ from this,

coregrind/m_syswrap/syswrap-linux.c

@@ -6499,6 +6499,9 @@ PRE(sys_ioctl)
    /* V4L2 */
    case VKI_V4L2_LOG_STATUS:
 
+   /* Mesa */
+   case VKI_DRM_IOCTL_I915_GEM_THROTTLE:
+
    /* DVB */
    case VKI_DMX_STOP:
       PRINT("sys_ioctl ( %" FMT_REGWORD "u, 0x%" FMT_REGWORD "x )", ARG1, ARG2);