From 49f19710512c825aaea73b9207b3a848027cda1d Mon Sep 17 00:00:00 2001 From: Zachary Amsden Date: Sun, 8 Apr 2007 16:04:01 -0700 Subject: [PATCH] Proper fix for highmem kmap_atomic functions for VMI for 2.6.21 Since lazy MMU batching mode still allows interrupts to enter, it is possible for interrupt handlers to try to use kmap_atomic, which fails when lazy mode is active, since the PTE update to highmem will be delayed. The best workaround is to issue an explicit flush in kmap_atomic_functions case; this is the only way nested PTE updates can happen in the interrupt handler. Thanks to Jeremy Fitzhardinge for noting the bug and suggestions on a fix. This patch gets reverted again when we start 2.6.22 and the bug gets fixed differently. Signed-off-by: Zachary Amsden Cc: Andi Kleen Cc: Jeremy Fitzhardinge Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/pgtable.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/asm-generic/pgtable.h') diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 00c23433b39..6d7e279b149 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -180,6 +180,7 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres #ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE #define arch_enter_lazy_mmu_mode() do {} while (0) #define arch_leave_lazy_mmu_mode() do {} while (0) +#define arch_flush_lazy_mmu_mode() do {} while (0) #endif /* @@ -193,6 +194,7 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres #ifndef __HAVE_ARCH_ENTER_LAZY_CPU_MODE #define arch_enter_lazy_cpu_mode() do {} while (0) #define arch_leave_lazy_cpu_mode() do {} while (0) +#define arch_flush_lazy_cpu_mode() do {} while (0) #endif /* -- cgit v1.2.3-18-g5258