---

 linux-2.6-npiggin/include/asm-sparc64/tlb.h |    6 +++++-
 linux-2.6-npiggin/kernel/fork.c             |    9 +++++----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff -puN include/asm-sparc64/mmu_context.h~vm-sparc64-updates include/asm-sparc64/mmu_context.h
diff -puN include/asm-sparc64/tlb.h~vm-sparc64-updates include/asm-sparc64/tlb.h
--- linux-2.6/include/asm-sparc64/tlb.h~vm-sparc64-updates	2004-10-30 12:29:49.000000000 +1000
+++ linux-2.6-npiggin/include/asm-sparc64/tlb.h	2004-10-30 12:30:46.000000000 +1000
@@ -44,7 +44,10 @@ extern void flush_tlb_pending(void);
 
 static inline struct mmu_gather *tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
 {
-	struct mmu_gather *mp = &per_cpu(mmu_gathers, smp_processor_id());
+	struct mmu_gather *mp;
+	
+	spin_lock(&mm->page_table_lock);
+	mp = &per_cpu(mmu_gathers, smp_processor_id());
 
 	BUG_ON(mp->tlb_nr);
 
@@ -99,6 +102,7 @@ static inline void tlb_finish_mmu(struct
 
 	/* keep the page table cache within bounds */
 	check_pgt_cache();
+	spin_unlock(&mm->page_table_lock);
 }
 
 static inline unsigned int tlb_is_full_mm(struct mmu_gather *mp)
diff -puN kernel/fork.c~vm-sparc64-updates kernel/fork.c
--- linux-2.6/kernel/fork.c~vm-sparc64-updates	2004-10-30 12:31:11.000000000 +1000
+++ linux-2.6-npiggin/kernel/fork.c	2004-10-30 12:34:12.000000000 +1000
@@ -447,11 +447,12 @@ static int copy_mm(unsigned long clone_f
 		 */
 		/*
 		 * XXX: I think this is only needed for sparc64's tlb and
-		 * context switching code - but sparc64 is in big trouble
-		 * now anyway because tlb_gather_mmu can be done without
-		 * holding the page table lock now anyway.
+		 * context switching code - this should actually be an arch
+		 * specific hook, but I'll just hack it for now. I'd rather
+		 * it not to use the page table lock at all, but DaveM would
+		 * probably think otherwise.
 		 */
-#if 0
+#ifdef CONFIG_SPARC64
 		spin_unlock_wait(&oldmm->page_table_lock);
 #endif
 		goto good_mm;

_