[patch 1/5] avoid tlb gather restarts.

[Martin Schwidefsky <schwidefsky@de.ibm.com>]

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

If need_resched() is false it is unnecessary to call tlb_finish_mmu()
and tlb_gather_mmu() for each vma in unmap_vmas(). Moving the tlb gather
restart under the if that contains the cond_resched() will avoid
unnecessary tlb flush operations that are triggered by tlb_finish_mmu() 
and tlb_gather_mmu().

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 mm/memory.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff -urpN linux-2.6/mm/memory.c linux-2.6-patched/mm/memory.c
--- linux-2.6/mm/memory.c	2007-06-29 15:44:08.000000000 +0200
+++ linux-2.6-patched/mm/memory.c	2007-06-29 15:44:08.000000000 +0200
@@ -851,19 +851,18 @@ unsigned long unmap_vmas(struct mmu_gath
 				break;
 			}
 
-			tlb_finish_mmu(*tlbp, tlb_start, start);
-
 			if (need_resched() ||
 				(i_mmap_lock && need_lockbreak(i_mmap_lock))) {
+				tlb_finish_mmu(*tlbp, tlb_start, start);
 				if (i_mmap_lock) {
 					*tlbp = NULL;
 					goto out;
 				}
 				cond_resched();
+				*tlbp = tlb_gather_mmu(vma->vm_mm, fullmm);
+				tlb_start_valid = 0;
 			}
 
-			*tlbp = tlb_gather_mmu(vma->vm_mm, fullmm);
-			tlb_start_valid = 0;
 			zap_work = ZAP_BLOCK_SIZE;
 		}
 	}

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/