diff -ru jdk-1_5_0-scsl.b4/hotspot/src/os/bsd/vm/os_bsd.cpp jdk-1_5_0-scsl.b4.fct2/hotspot/src/os/bsd/vm/os_bsd.cpp
--- jdk-1_5_0-scsl.b4/hotspot/src/os/bsd/vm/os_bsd.cpp	2007-01-24 11:12:39.000000000 +0100
+++ jdk-1_5_0-scsl.b4.fct2/hotspot/src/os/bsd/vm/os_bsd.cpp	2007-02-22 23:53:00.000000000 +0100
@@ -138,15 +138,39 @@
   // thread value in thread local storage.
 #endif
 
+  uintptr_t raw = pd_raw_thread_id();
+  int ix = pd_cache_index(raw);
+
+  if (thread != NULL) {
+    // first make sure that nobody gets a cache collision pointing to
+    // this thread by updating its raw id
+    thread->_self_raw_id = raw;
+
   // Store the new value before updating the cache to prevent a race
   // between get_thread_via_cache_slowly() and this store operation.
   os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);
 
-  // Update thread cache with new thread if setting on thread create,
-  // or NO_CACHED_THREAD (zeroed) thread if resetting thread on exit.
-  uintptr_t raw = pd_raw_thread_id();
-  int ix = pd_cache_index(raw);
-  _get_thread_cache[ix] = thread == NULL ? NO_CACHED_THREAD : thread;
+    // Update thread cache with new thread if setting on thread create
+    _get_thread_cache[ix] = thread;
+  } else {
+    // deleting current thread, must get old value first
+    Thread* was_thread = Thread::current();
+
+    // first make sure that nobody gets a cache collision pointing to
+    // the old thread data (soon to be free'd) by updating the raw id
+    was_thread->_self_raw_id = raw;
+
+    // again, update the "real" value first:
+    os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);
+
+    // then invalidate all cache elements that pointed to this thread
+    // by setting them to NO_CACHED_THREAD (zeroed thread)
+    for (int ix = 0; ix < _pd_cache_size; ++ix) {
+      if (_get_thread_cache[ix] == was_thread) {
+        _get_thread_cache[ix] = NO_CACHED_THREAD;
+      }
+    }
+  }
 }
 
 void ThreadLocalStorage::pd_init() {
@@ -1190,7 +1214,7 @@
 // XXXBSD: hmm...  really do not need?
 void os::free_thread_local_storage(int index) {
   // %%% don't think we need anything here
-  // if ( pthread_key_delete((pthread_key_t) tk) )
+  // if ( pthread_key_delete((pthread_key_t) index) )
   //   fatal("os::free_thread_local_storage: pthread_key_delete failed");
 }
 
Only in jdk-1_5_0-scsl.b4.fct2/hotspot/src/os/bsd/vm: os_bsd.cpp.orig
diff -ru jdk-1_5_0-scsl.b4/hotspot/src/os/bsd/vm/thread_bsd.inline.hpp jdk-1_5_0-scsl.b4.fct2/hotspot/src/os/bsd/vm/thread_bsd.inline.hpp
--- jdk-1_5_0-scsl.b4/hotspot/src/os/bsd/vm/thread_bsd.inline.hpp	2007-01-24 11:12:39.000000000 +0100
+++ jdk-1_5_0-scsl.b4.fct2/hotspot/src/os/bsd/vm/thread_bsd.inline.hpp	2007-02-22 23:53:00.000000000 +0100
@@ -19,18 +19,31 @@
 
   uintptr_t raw = pd_raw_thread_id();
   int ix = pd_cache_index(raw);
-// XXXBSD: disable fast case. there is a race condition where the
-// fast case returns a different thread from the slow case and has
-// been seen on both OpenBSD and FreeBSD.
+// XXXBSD: fast case.
+// there was a race condition where the fast case returned a different
+// thread from the slow case and has been seen on both OpenBSD and
+// FreeBSD, but I think it's fixed, so enable it for now:
 #if 1
-  return ThreadLocalStorage::get_thread_via_cache_slowly(raw, ix);
-#else
   Thread *Candidate = ThreadLocalStorage::_get_thread_cache[ix];
+
   if (Candidate->_self_raw_id == raw) {
-    // hit
+        // direct hit
     return Candidate;
-  } else {
-    return ThreadLocalStorage::get_thread_via_cache_slowly(raw, ix);
   }
+
+    address stacktop = Candidate->_stack_base;
+    address stackbot = Candidate->_stack_base - Candidate->_stack_size;
+
+    address sp = pd_sp_address();
+
+    // is this still the right thread?  Check if current stack pointer
+    // is within the thread's stack, if ok update it with current raw id.
+    if (stacktop > sp && stackbot <= sp ) {
+        Candidate->_self_raw_id = raw;
+        // indirect hit
+        return Candidate;
+    }
+    ix = pd_cache_index(raw);
 #endif
+    return ThreadLocalStorage::get_thread_via_cache_slowly(raw, ix);
 }
Only in jdk-1_5_0-scsl.b4.fct2/hotspot/src/os/bsd/vm: thread_bsd.inline.hpp.orig
diff -ru jdk-1_5_0-scsl.b4/hotspot/src/os_cpu/bsd_amd64/vm/threadLS_bsd_amd64.hpp jdk-1_5_0-scsl.b4.fct2/hotspot/src/os_cpu/bsd_amd64/vm/threadLS_bsd_amd64.hpp
--- jdk-1_5_0-scsl.b4/hotspot/src/os_cpu/bsd_amd64/vm/threadLS_bsd_amd64.hpp	2007-01-24 11:12:39.000000000 +0100
+++ jdk-1_5_0-scsl.b4.fct2/hotspot/src/os_cpu/bsd_amd64/vm/threadLS_bsd_amd64.hpp	2007-02-22 23:53:00.000000000 +0100
@@ -9,7 +9,7 @@
 // Processor dependent parts of ThreadLocalStorage
 
 private:
-  static Thread* _get_thread_cache[];  // index by [(raw_id>>9)^(raw_id>>20) % _pd_cache_size]
+  static Thread* _get_thread_cache[];  // index by [(raw_id^(raw_id>>10)) % _pd_cache_size]
   static Thread* get_thread_via_cache_slowly(uintptr_t raw_id, int index);
 
   NOT_PRODUCT(static int _tcacheHit;)
@@ -20,8 +20,8 @@
   static void print_statistics() PRODUCT_RETURN;
 
   enum Constants {
-    _pd_cache_size         =  128*2,   // projected typical # of threads * 2
-
+    // projected typical # of threads * 2 * typical active stack pages
+    _pd_cache_size         =  128*2*4,
     _pd_min_page_size	   =  4*K,
     _pd_typical_stack_size =  512*K
   };
@@ -37,9 +37,8 @@
   }
 
   static int pd_cache_index(uintptr_t sp_page) {
-    return ((sp_page / 2)  /* pages tend to come in pairs */
-         ^ (sp_page / (_pd_typical_stack_size/_pd_min_page_size)))
-         % _pd_cache_size;
+    // _pd_cache_size == 1<<10
+    return (sp_page ^ (sp_page >> 10)) % _pd_cache_size;
   }
 
   // Java Thread
Only in jdk-1_5_0-scsl.b4.fct2/hotspot/src/os_cpu/bsd_amd64/vm: threadLS_bsd_amd64.hpp.orig
diff -ru jdk-1_5_0-scsl.b4/hotspot/src/os_cpu/bsd_i486/vm/threadLS_bsd_i486.hpp jdk-1_5_0-scsl.b4.fct2/hotspot/src/os_cpu/bsd_i486/vm/threadLS_bsd_i486.hpp
--- jdk-1_5_0-scsl.b4/hotspot/src/os_cpu/bsd_i486/vm/threadLS_bsd_i486.hpp	2007-01-24 11:12:39.000000000 +0100
+++ jdk-1_5_0-scsl.b4.fct2/hotspot/src/os_cpu/bsd_i486/vm/threadLS_bsd_i486.hpp	2007-02-22 23:53:00.000000000 +0100
@@ -9,7 +9,7 @@
 // Processor dependent parts of ThreadLocalStorage
 
 private:
-  static Thread* _get_thread_cache[];  // index by [(raw_id>>9)^(raw_id>>20) % _pd_cache_size]
+  static Thread* _get_thread_cache[];  // index by [(raw_id^(raw_id>>10)) % _pd_cache_size]
   static Thread* get_thread_via_cache_slowly(uintptr_t raw_id, int index);
 
   NOT_PRODUCT(static int _tcacheHit;)
@@ -20,26 +20,26 @@
   static void print_statistics() PRODUCT_RETURN;
 
   enum Constants {
-    _pd_cache_size         =  128*2,   // projected typical # of threads * 2
-
+    // projected typical # of threads * typical active stack pages * 2
+    _pd_cache_size         =  128*2*4,
     _pd_min_page_size	   =  4*K,
     _pd_typical_stack_size =  512*K
   };
 
   static address pd_sp_address() {
-    int junk;
-    return (address)&junk;
+    address sp;
+    __asm__ volatile ("movl %%esp, %0" : "=r" (sp));
+    return sp;
   }
 
   static uintptr_t pd_raw_thread_id() {
-    address sp = pd_sp_address();
-    return (unsigned int)sp / _pd_min_page_size;
+    // _pd_min_page_size == 1 << 12
+    return ((unsigned int)pd_sp_address()) >> 12;
   }
 
   static int pd_cache_index(uintptr_t sp_page) {
-    return ((sp_page / 2)  /* pages tend to come in pairs */
-         ^ (sp_page / (_pd_typical_stack_size/_pd_min_page_size)))
-         % _pd_cache_size;
+    // _pd_cache_size == 1<<10
+    return (sp_page ^ (sp_page >> 10)) % _pd_cache_size;
   }
 
   // Java Thread
Only in jdk-1_5_0-scsl.b4.fct2/hotspot/src/os_cpu/bsd_i486/vm: threadLS_bsd_i486.hpp.orig
diff -ru jdk-1_5_0-scsl.b4/hotspot/src/share/vm/runtime/thread.cpp jdk-1_5_0-scsl.b4.fct2/hotspot/src/share/vm/runtime/thread.cpp
--- jdk-1_5_0-scsl.b4/hotspot/src/share/vm/runtime/thread.cpp	2007-01-24 10:40:33.000000000 +0100
+++ jdk-1_5_0-scsl.b4.fct2/hotspot/src/share/vm/runtime/thread.cpp	2007-02-22 23:53:01.000000000 +0100
@@ -104,6 +104,11 @@
 
   delete _SR_lock;
   
+  // to make sure nobody finds the deleted thread as a current thread
+  // in the cache (when comparing stack pointers)
+  set_stack_base(0);
+  set_stack_size(0);
+
   // clear thread local storage if the Thread is deleting itself
   if (this == Thread::current()) {
     ThreadLocalStorage::set_thread(NULL);
Only in jdk-1_5_0-scsl.b4.fct2/hotspot/src/share/vm/runtime: thread.cpp.orig