config/kernel-spinlock.m4

   1 dnl #
   2 dnl # 2.6.36 API change,
   3 dnl # The 'struct fs_struct->lock' was changed from a rwlock_t to
   4 dnl # a spinlock_t to improve the fastpath performance.
   5 dnl #
   6 AC_DEFUN([ZFS_AC_KERNEL_FS_STRUCT_SPINLOCK], [
   7         AC_MSG_CHECKING([whether struct fs_struct uses spinlock_t])
   8         tmp_flags="$EXTRA_KCFLAGS"
   9         EXTRA_KCFLAGS="-Werror"
  10         ZFS_LINUX_TRY_COMPILE([
  11                 #include <linux/sched.h>
  12                 #include <linux/fs_struct.h>
  13         ],[
  14                 static struct fs_struct fs;
  15                 spin_lock_init(&fs.lock);
  16         ],[
  17                 AC_MSG_RESULT(yes)
  18                 AC_DEFINE(HAVE_FS_STRUCT_SPINLOCK, 1,
  19                           [struct fs_struct uses spinlock_t])
  20         ],[
  21                 AC_MSG_RESULT(no)
  22         ])
  23         EXTRA_KCFLAGS="$tmp_flags"
  24 ])