Commit major SMP cleanups and move the BGL (big giant lock) in the

    syscall path inward.  A system call may select whether it needs the MP
    lock or not (the default being that it does need it).

    A great deal of conditional SMP code for various deadended experiments
    has been removed.  'cil' and 'cml' have been removed entirely, and the
    locking around the cpl has been removed.  The conditional
    separately-locked fast-interrupt code has been removed, meaning that
    interrupts must hold the CPL now (but they pretty much had to anyway).
    Another reason for doing this is that the original separate-lock for
    interrupts just doesn't apply to the interrupt thread mechanism being
    contemplated.

    Modifications to the cpl may now ONLY occur while holding the MP
    lock.  For example, if an otherwise MP safe syscall needs to mess with
    the cpl, it must hold the MP lock for the duration and must (as usual)
    save/restore the cpl in a nested fashion.

    This is precursor work for the real meat coming later: avoiding having
    to hold the MP lock for common syscalls and I/O's and interrupt threads.
    It is expected that the spl mechanisms and new interrupt threading
    mechanisms will be able to run in tandem, allowing a slow piecemeal
    transition to occur.

    This patch should result in a moderate performance improvement due to
    the considerable amount of code that has been removed from the critical
    path, especially the simplification of the spl*() calls.  The real
    performance gains will come later.

Approved by: jkh
Reviewed by: current, bde (exception.s)
Some work taken from: luoqi's patch

1 files changed, 2 insertions, 3 deletions

diff --git a/sys/i386/include/asnames.h b/sys/i386/include/asnames.h
index b9b631d..3ccbee6 100644
--- a/sys/i386/include/asnames.h
+++ b/sys/i386/include/asnames.h
@@ -155,7 +155,6 @@
 #define _arith_invalid			arith_invalid
 #define _arith_overflow			arith_overflow
 #define _arith_underflow		arith_underflow
-#define _astpending			astpending
 #define _bcopy				bcopy
 #define _bcopy_vector			bcopy_vector
 #define _bigJump			bigJump
@@ -307,7 +306,7 @@
 #define _swi_generic			swi_generic
 #define _swi_null			swi_null
 #define _swi_vm				swi_vm
-#define _syscall			syscall
+#define _syscall2			syscall2
 #define _szsigcode			szsigcode
 #define _ticks				ticks
 #define _time				time
@@ -321,7 +320,6 @@
 #define _vm86paddr			vm86paddr
 #define _vm86pcb			vm86pcb
 #define _vm_page_zero_idle		vm_page_zero_idle
-#define _want_resched			want_resched
 #define _wm_sqrt			wm_sqrt
 
 #endif /* __ELF__ */
@@ -339,6 +337,7 @@
 #define _cpu_lockid			FS(cpu_lockid)
 #define _curpcb				FS(curpcb)
 #define _curproc			FS(curproc)
+#define _astpending			FS(astpending)
 #define _currentldt			FS(currentldt)
 #define _inside_intr			FS(inside_intr)
 #define _npxproc			FS(npxproc)