diff options
| -rw-r--r-- | sys/i386/i386/pmap.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/sys/i386/i386/pmap.c b/sys/i386/i386/pmap.c index b973d0d..cbcb937 100644 --- a/sys/i386/i386/pmap.c +++ b/sys/i386/i386/pmap.c @@ -4482,6 +4482,7 @@ pmap_change_attr(vm_offset_t va, vm_size_t size, int mode) pt_entry_t *pte; u_int opte, npte; pd_entry_t *pde; + boolean_t changed; base = trunc_page(va); offset = va & PAGE_MASK; @@ -4505,6 +4506,8 @@ pmap_change_attr(vm_offset_t va, vm_size_t size, int mode) return (EINVAL); } + changed = FALSE; + /* * Ok, all the pages exist and are 4k, so run through them updating * their cache mode. @@ -4522,6 +4525,8 @@ pmap_change_attr(vm_offset_t va, vm_size_t size, int mode) npte |= pmap_cache_bits(mode, 0); } while (npte != opte && !atomic_cmpset_int((u_int *)pte, opte, npte)); + if (npte != opte) + changed = TRUE; tmpva += PAGE_SIZE; size -= PAGE_SIZE; } @@ -4530,10 +4535,12 @@ pmap_change_attr(vm_offset_t va, vm_size_t size, int mode) * Flush CPU caches to make sure any data isn't cached that shouldn't * be, etc. */ - pmap_invalidate_range(kernel_pmap, base, tmpva); - /* If "Self Snoop" is supported, do nothing. */ - if (!(cpu_feature & CPUID_SS)) - pmap_invalidate_cache(); + if (changed) { + pmap_invalidate_range(kernel_pmap, base, tmpva); + /* If "Self Snoop" is supported, do nothing. */ + if (!(cpu_feature & CPUID_SS)) + pmap_invalidate_cache(); + } return (0); } |
