vm_page_t related KBI [Was: Re: panic at vm_page_wire with FreeBSD 9.0 Beta 3]

[mdf at FreeBSD.org]

On Mon, Nov 7, 2011 at 11:35 AM, Kostik Belousov <kostikbel at gmail.com> wrote:
> On Mon, Nov 07, 2011 at 11:45:38AM -0600, Alan Cox wrote:
>> Ok.  I'll offer one final suggestion.  Please consider an alternative
>> suffix to "func".  Perhaps, "kbi" or "KBI".  In other words, something
>> that hints at the function's reason for existing.
>
> Sure. Below is the extraction of only vm_page_lock() bits, together
> with the suggested rename. When Attilio provides the promised simplification
> of the mutex KPI, this can be reduced.
>
> diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
> index 389aea5..ea4ea34 100644
> --- a/sys/vm/vm_page.c
> +++ b/sys/vm/vm_page.c
> @@ -2677,6 +2677,44 @@ vm_page_test_dirty(vm_page_t m)
>                vm_page_dirty(m);
>  }
>
> +void
> +vm_page_lock_KBI(vm_page_t m, const char *file, int line)
> +{
> +
> +#if LOCK_DEBUG > 0 || defined(MUTEX_NOINLINE)
> +       _mtx_lock_flags(vm_page_lockptr(m), 0, file, line);
> +#else
> +       __mtx_lock(vm_page_lockptr(m), 0, file, line);
> +#endif
> +}
> +
> +void
> +vm_page_unlock_KBI(vm_page_t m, const char *file, int line)
> +{
> +
> +#if LOCK_DEBUG > 0 || defined(MUTEX_NOINLINE)
> +       _mtx_unlock_flags(vm_page_lockptr(m), 0, file, line);
> +#else
> +       __mtx_unlock(vm_page_lockptr(m), curthread, 0, file, line);
> +#endif
> +}
> +
> +int
> +vm_page_trylock_KBI(vm_page_t m, const char *file, int line)
> +{
> +
> +       return (_mtx_trylock(vm_page_lockptr(m), 0, file, line));
> +}
> +
> +void
> +vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line)
> +{
> +
> +#ifdef INVARIANTS
> +       _mtx_assert(vm_page_lockptr(m), a, file, line);
> +#endif
> +}
> +
>  int so_zerocp_fullpage = 0;
>
>  /*
> diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h
> index 7099b70..a5604b7 100644
> --- a/sys/vm/vm_page.h
> +++ b/sys/vm/vm_page.h
> @@ -218,11 +218,23 @@ extern struct vpglocks pa_lock[];
>
>  #define        PA_LOCK_ASSERT(pa, a)   mtx_assert(PA_LOCKPTR(pa), (a))
>
> +#ifdef KLD_MODULE
> +#define        vm_page_lock(m)         vm_page_lock_KBI((m), LOCK_FILE, LOCK_LINE)
> +#define        vm_page_unlock(m)       vm_page_unlock_KBI((m), LOCK_FILE, LOCK_LINE)
> +#define        vm_page_trylock(m)      vm_page_trylock_KBI((m), LOCK_FILE, LOCK_LINE)
> +#ifdef INVARIANTS
> +#define        vm_page_lock_assert(m, a)       \
> +    vm_page_lock_assert_KBI((m), (a), LOCK_FILE, LOCK_LINE)
> +#else
> +#define        vm_page_lock_assert(m, a)
> +#endif
> +#else  /* KLD_MODULE */
>  #define        vm_page_lockptr(m)      (PA_LOCKPTR(VM_PAGE_TO_PHYS((m))))

Is it not possible to have vm_page_lockptr() be a function for the
KLD_MODULE case?  Because then the vm_page_lock() functions and
friends would all just use mtx_lock, etc., in both the KLD and non-KLD
case.

Or am I missing something?

Thanks,
matthew

>  #define        vm_page_lock(m)         mtx_lock(vm_page_lockptr((m)))
>  #define        vm_page_unlock(m)       mtx_unlock(vm_page_lockptr((m)))
>  #define        vm_page_trylock(m)      mtx_trylock(vm_page_lockptr((m)))
>  #define        vm_page_lock_assert(m, a)       mtx_assert(vm_page_lockptr((m)), (a))
> +#endif
>
>  #define        vm_page_queue_free_mtx  vm_page_queue_free_lock.data
>  /*
> @@ -403,6 +415,11 @@ void vm_page_cowfault (vm_page_t);
>  int vm_page_cowsetup(vm_page_t);
>  void vm_page_cowclear (vm_page_t);
>
> +void vm_page_lock_KBI(vm_page_t m, const char *file, int line);
> +void vm_page_unlock_KBI(vm_page_t m, const char *file, int line);
> +int vm_page_trylock_KBI(vm_page_t m, const char *file, int line);
> +void vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line);
> +
>  #ifdef INVARIANTS
>  void vm_page_object_lock_assert(vm_page_t m);
>  #define        VM_PAGE_OBJECT_LOCK_ASSERT(m)   vm_page_object_lock_assert(m)
>