[mirror_zfs-debian.git] / config / kernel-blk-queue-nonrot.m4

dnl #
dnl # 2.6.27 API change
dnl # The blk_queue_nonrot() function and QUEUE_FLAG_NONROT flag were
dnl # added so non-rotational devices could be identified.  These devices
dnl # have no seek time which the higher level elevator uses to optimize
dnl # how the I/O issued to the device.
dnl #
AC_DEFUN([ZFS_AC_KERNEL_BLK_QUEUE_NONROT], [
	AC_MSG_CHECKING([whether blk_queue_nonrot() is available])
	tmp_flags="$EXTRA_KCFLAGS"
	EXTRA_KCFLAGS="-Wno-unused-but-set-variable"
	ZFS_LINUX_TRY_COMPILE([
		#include <linux/blkdev.h>
	],[
		struct request_queue *q = NULL;
		(void) blk_queue_nonrot(q);
	],[
		AC_MSG_RESULT(yes)
		AC_DEFINE(HAVE_BLK_QUEUE_NONROT, 1,
		          [blk_queue_nonrot() is available])
	],[
		AC_MSG_RESULT(no)
	])
	EXTRA_KCFLAGS="$tmp_flags"
])
Commit	Line	Data
34037afe ED	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="$EXTRA_KCFLAGS"
	11	EXTRA_KCFLAGS="-Wno-unused-but-set-variable"
	12	ZFS_LINUX_TRY_COMPILE([
	13	#include <linux/blkdev.h>
	14	],[
	15	struct request_queue *q = NULL;
	16	(void) blk_queue_nonrot(q);
	17	],[
	18	AC_MSG_RESULT(yes)
	19	AC_DEFINE(HAVE_BLK_QUEUE_NONROT, 1,
	20	[blk_queue_nonrot() is available])
	21	],[
	22	AC_MSG_RESULT(no)
	23	])
	24	EXTRA_KCFLAGS="$tmp_flags"
	25	])