config/kernel-blk-queue-nonrot.m4

   1 dnl #
   2 dnl # 2.6.27 API change
   3 dnl # The blk_queue_nonrot() function and QUEUE_FLAG_NONROT flag were
   4 dnl # added so non-rotational devices could be identified.  These devices
   5 dnl # have no seek time which the higher level elevator uses to optimize
   6 dnl # how the I/O issued to the device.
   7 dnl #
   8 AC_DEFUN([ZFS_AC_KERNEL_BLK_QUEUE_NONROT], [
   9         AC_MSG_CHECKING([whether blk_queue_nonrot() is available])
  10         tmp_flags="$EXTRA_KCFLAGS"
  11         EXTRA_KCFLAGS="${NO_UNUSED_BUT_SET_VARIABLE}"
  12         ZFS_LINUX_TRY_COMPILE([
  13                 #include <linux/blkdev.h>
  14         ],[
  15                 struct request_queue *q = NULL;
  16                 (void) blk_queue_nonrot(q);
  17         ],[
  18                 AC_MSG_RESULT(yes)
  19                 AC_DEFINE(HAVE_BLK_QUEUE_NONROT, 1,
  20                           [blk_queue_nonrot() is available])
  21         ],[
  22                 AC_MSG_RESULT(no)
  23         ])
  24         EXTRA_KCFLAGS="$tmp_flags"
  25 ])