[sir_richard] 45271: [PERF]: What to do when your SYSEXIT code has a bug? Set KiFastSystemCallDisable to TRUE so it never gets used. Now, for the first time in 3 years and 3 months (not giving a specific revision # to protect the 'innocent'), ReactOS actually fully uses the SYSENTER/SYSEXIT instructions isntead of IRETD, since my code doesn't exhibit the bug and SYSEXIT is safe to use. This should save a good hundred cycles or more per system call.

Author: sir_richard
Date: Tue Jan 26 20:39:21 2010
New Revision: 45271

URL: http://svn.reactos.org/svn/reactos?rev=45271&view=rev
Log:
[PERF]: What to do when your SYSEXIT code has a bug? Set KiFastSystemCallDisable to TRUE
so it never gets used. Now, for the first time in 3 years and 3 months (not giving a
specific revision # to protect the 'innocent'), ReactOS actually fully uses the
SYSENTER/SYSEXIT instructions isntead of IRETD, since my code doesn't exhibit the bug
and SYSEXIT is safe to use. This should save a good hundred cycles or more per system
call.

Modified:
    trunk/reactos/ntoskrnl/ke/i386/cpu.c

Modified: trunk/reactos/ntoskrnl/ke/i386/cpu.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ke/i386/cpu.c?rev…
==============================================================================
--- trunk/reactos/ntoskrnl/ke/i386/cpu.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/ke/i386/cpu.c [iso-8859-1] Tue Jan 26 20:39:21 2010
@@ -27,7 +27,7 @@
 ULONG KeProcessorLevel;
 ULONG KeProcessorRevision;
 ULONG KeFeatureBits;
-ULONG KiFastSystemCallDisable = 1;
+ULONG KiFastSystemCallDisable;
 ULONG KeI386NpxPresent = 0;
 ULONG KiMXCsrMask = 0;
 ULONG MxcsrFeatureMask = 0;