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.
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>
15 struct request_queue *q = NULL;
16 (void) blk_queue_nonrot(q);
19 AC_DEFINE(HAVE_BLK_QUEUE_NONROT, 1,
20 [blk_queue_nonrot() is available])
24 EXTRA_KCFLAGS="$tmp_flags"