[PATCH 19/24] powerpc/mm: Add a bunch of (un)likely annotations to do_page_fault

[Benjamin Herrenschmidt]

Mostly for the failure cases

Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
---
 arch/powerpc/mm/fault.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index c5859ffd3a96..f1abdc90e330 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -400,7 +400,7 @@ static int __do_page_fault(struct pt_regs *regs, unsigned 
long address,
         * source.  If this is invalid we can skip the address space check,
         * thus avoiding the deadlock.
         */
-       if (!down_read_trylock(&mm->mmap_sem)) {
+       if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
                if (!is_user && !search_exception_tables(regs->nip))
                        return bad_area_nosemaphore(regs, address);
 
@@ -416,11 +416,11 @@ static int __do_page_fault(struct pt_regs *regs, unsigned 
long address,
        }
 
        vma = find_vma(mm, address);
-       if (!vma)
+       if (unlikely(!vma))
                return bad_area(regs, address);
-       if (vma->vm_start <= address)
+       if (likely(vma->vm_start <= address))
                goto good_area;
-       if (!(vma->vm_flags & VM_GROWSDOWN))
+       if (unlikely(!(vma->vm_flags & VM_GROWSDOWN)))
                return bad_area(regs, address);
 
        /*
@@ -453,7 +453,7 @@ static int __do_page_fault(struct pt_regs *regs, unsigned 
long address,
                if (address + 2048 < uregs->gpr[1] && !store_update_sp)
                        return bad_area(regs, address);
        }
-       if (expand_stack(vma, address))
+       if (unlikely(expand_stack(vma, address)))
                return bad_area(regs, address);
 
 good_area:
@@ -468,18 +468,18 @@ static int __do_page_fault(struct pt_regs *regs, unsigned 
long address,
                 * below wouldn't be valid on those processors. This -may-
                 * break programs compiled with a really old ABI though.
                 */
-               if (!(vma->vm_flags & VM_EXEC) &&
-                   (cpu_has_feature(CPU_FTR_NOEXECUTE) ||
-                    !(vma->vm_flags & (VM_READ | VM_WRITE))))
+               if (unlikely(!(vma->vm_flags & VM_EXEC) &&
+                            (cpu_has_feature(CPU_FTR_NOEXECUTE) ||
+                             !(vma->vm_flags & (VM_READ | VM_WRITE)))))
                        return bad_area(regs, address);
        /* a write */
        } else if (is_write) {
-               if (!(vma->vm_flags & VM_WRITE))
+               if (unlikely(!(vma->vm_flags & VM_WRITE)))
                        return bad_area(regs, address);
                flags |= FAULT_FLAG_WRITE;
        /* a read */
        } else {
-               if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
+               if (unlikely(!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))))
                        return bad_area(regs, address);
        }
 
-- 
2.13.3