freebsd-nq/config/kernel-timer.m4
Rafael Kitover 8b8b44d06f kernel timer API rework
In `config/kernel-timer.m4` refactor slightly to check more generally
for the new `timer_setup()` APIs, but also check the callback signature
because some kernels (notably 4.14) have the new `timer_setup()` API but
use the old callback signature. Also add a check for a `flags` member in
`struct timer_list`, which was added in 4.1-rc8.

Add compatibility shims to `include/spl/sys/timer.h` to allow using the
new timer APIs with the only two caveats being that the callback
argument type must be declared as `spl_timer_list_t` and an explicit
assignment is required to get the timer variable for the `timer_of()`
macro. So the callback would look like this:

```c
__cv_wakeup(spl_timer_list_t t)
{
        struct timer_list *tmr = (struct timer_list *)t;
	struct thing *parent = from_timer(parent, tmr,
		parent_timer_field);
	... /* do stuff with parent */
```

Make some minor changes to `spl-condvar.c` and `spl-taskq.c` to use the
new timer APIs instead of conditional code.

Reviewed-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rafael Kitover <rkitover@gmail.com>
Closes #8647
2019-05-23 14:40:28 -07:00

74 lines
1.8 KiB
Plaintext

dnl # 4.14-rc3 API change
dnl # https://lwn.net/Articles/735887/
dnl #
dnl # Check if timer_list.func get passed a timer_list or an unsigned long
dnl # (older kernels). Also sanity check the from_timer() and timer_setup()
dnl # macros are available as well, since they will be used in the same newer
dnl # kernels that support the new timer_list.func signature.
dnl #
dnl # Also check for the existance of flags in struct timer_list, they were
dnl # added in 4.1-rc8 via 0eeda71bc30d.
AC_DEFUN([ZFS_AC_KERNEL_TIMER_SETUP], [
AC_MSG_CHECKING([whether timer_setup() is available])
tmp_flags="$EXTRA_KCFLAGS"
EXTRA_KCFLAGS="-Werror"
ZFS_LINUX_TRY_COMPILE([
#include <linux/timer.h>
struct my_task_timer {
struct timer_list timer;
int data;
};
void task_expire(struct timer_list *tl)
{
struct my_task_timer *task_timer = from_timer(task_timer, tl, timer);
task_timer->data = 42;
}
],[
struct my_task_timer task_timer;
timer_setup(&task_timer.timer, task_expire, 0);
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_KERNEL_TIMER_SETUP, 1,
[timer_setup() is available])
],[
AC_MSG_RESULT(no)
])
AC_MSG_CHECKING([whether timer function expects timer_list])
ZFS_LINUX_TRY_COMPILE([
#include <linux/timer.h>
void task_expire(struct timer_list *tl) {}
],[
struct timer_list tl;
tl.function = task_expire;
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_KERNEL_TIMER_FUNCTION_TIMER_LIST, 1,
[timer_list.function gets a timer_list])
],[
AC_MSG_RESULT(no)
])
AC_MSG_CHECKING([whether struct timer_list has flags])
ZFS_LINUX_TRY_COMPILE([
#include <linux/timer.h>
],[
struct timer_list tl;
tl.flags = 2;
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_KERNEL_TIMER_LIST_FLAGS, 1,
[struct timer_list has a flags member])
],[
AC_MSG_RESULT(no)
])
EXTRA_KCFLAGS="$tmp_flags"
])