From d5f067aa735968d4da6685f0883ca978d5e6795c Mon Sep 17 00:00:00 2001
From: Jeffrey Altman <jaltman@your-file-system.com>
Date: Thu, 5 Jul 2012 16:52:51 -0400
Subject: [PATCH] Windows: use spin counts for osi base locks

On multiprocessor systems, spin counts are faster than entering
a processor wait state when there is critical section contention.
Microsoft recommends a count of 4000.  This feature is only available
on XP and above which is fine since OpenAFS master and 1.7 no longer
support Windows 2000.

Change-Id: I1b40d00b2a91e60e1676a53e1c38eb5f9bfadc69
Reviewed-on: http://gerrit.openafs.org/7719
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
---
 src/WINNT/client_osi/osibasel.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/WINNT/client_osi/osibasel.c b/src/WINNT/client_osi/osibasel.c
index eb00b15ecb..156993c7de 100644
--- a/src/WINNT/client_osi/osibasel.c
+++ b/src/WINNT/client_osi/osibasel.c
@@ -35,7 +35,7 @@ void osi_BaseInit(void)
     int i;
 
     for(i=0; i<OSI_MUTEXHASHSIZE; i++)
-        InitializeCriticalSection(&osi_baseAtomicCS[i]);
+        InitializeCriticalSectionAndSpinCount(&osi_baseAtomicCS[i], 4000);
 
     if ((tls_LockRefH = TlsAlloc()) == TLS_OUT_OF_INDEXES)
         osi_panic("TlsAlloc(tls_LockRefH) failure", __FILE__, __LINE__);
@@ -43,7 +43,7 @@ void osi_BaseInit(void)
     if ((tls_LockRefT = TlsAlloc()) == TLS_OUT_OF_INDEXES)
         osi_panic("TlsAlloc(tls_LockRefT) failure", __FILE__, __LINE__);
 
-    InitializeCriticalSection(&lock_ref_CS);
+    InitializeCriticalSectionAndSpinCount(&lock_ref_CS, 4000);
 }
 
 void