Stop updating the struct vdso_timehands from even handler executed in

the scheduled task from tc_windup(). Do it directly from tc_windup in
interrupt context [1].

Establish the permanent mapping of the shared page into the kernel
address space, avoiding the potential need to sleep waiting for
allocation of sf buffer during vdso_timehands update. As a
consequence, shared_page_write_start() and shared_page_write_end()
functions are not needed anymore.

Guess and memorize the pointers to native host and compat32 sysentvec
during initialization, to avoid the need to get shared_page_alloc_sx
lock during the update.

In tc_fill_vdso_timehands(), do not loop waiting for timehands
generation to stabilize, since vdso_timehands is written in the same
interrupt context which wrote timehands.

Requested by:	  mav [1]
MFC after:	  29 days

1 files changed, 0 insertions, 2 deletions

diff --git a/sys/sys/sysent.h b/sys/sys/sysent.h
index 22769c2..6de72d9 100644
--- a/sys/sys/sysent.h
+++ b/sys/sys/sysent.h
@@ -265,8 +265,6 @@ int shared_page_alloc(int size, int align);
 int shared_page_fill(int size, int align, const void *data);
 void shared_page_write(int base, int size, const void *data);
 void exec_sysvec_init(void *param);
-struct sf_buf *shared_page_write_start(int base);
-void shared_page_write_end(struct sf_buf *sf);
 
 #define INIT_SYSENTVEC(name, sv)					\
     SYSINIT(name, SI_SUB_EXEC, SI_ORDER_ANY,				\