TLB flush counters gone in 2.5.35-bk?

From: Roberto Nibali (ratz@drugphish.ch)
Date: Tue Sep 17 2002 - 10:43:29 EST

Hello,

I was just browsing over the latest bk tree when I saw the following change:

--- a/include/asm-generic/tlb.h Thu Aug 29 13:27:24 2002
+++ b/include/asm-generic/tlb.h Mon Sep 9 14:58:18 2002
@@ -21,7 +21,7 @@
   * and page free order so much..
   */
  #ifdef CONFIG_SMP
- #define FREE_PTE_NR 507
+ #define FREE_PTE_NR 506
    #define tlb_fast_mode(tlb) ((tlb)->nr == ~0U)
  #else
    #define FREE_PTE_NR 1
@@ -40,8 +40,6 @@
         unsigned int fullmm; /* non-zero means full mm flush */
         unsigned long freed;
         struct page * pages[FREE_PTE_NR];
- unsigned long flushes;/* stats: count avoided flushes */
- unsigned long avoided_flushes;
  } mmu_gather_t;

  /* Users of the generic TLB shootdown code must declare this storage
space. */
@@ -67,17 +65,10 @@

  static inline void tlb_flush_mmu(mmu_gather_t *tlb, unsigned long
start, unsigned long en
d)
  {
- unsigned long nr;
-
- if (!tlb->need_flush) {
- tlb->avoided_flushes++;
+ if (!tlb->need_flush)
                 return;
- }
         tlb->need_flush = 0;
- tlb->flushes++;
-
         tlb_flush(tlb);
- nr = tlb->nr;
         if (!tlb_fast_mode(tlb)) {
                 free_pages_and_swap_cache(tlb->pages, tlb->nr);
                 tlb->nr = 0;

Why was that done? I'm actually about to conduct some tests where I
think that I need this information to check the L1 <-> L2 caching size
influence on kernel data structures. What is the problem with the
existing counters, did I miss some discussion on LKML?

Best regards,
Roberto Nibali, ratz 

-- 
echo '[q]sa[ln0=aln256%Pln256/snlbx]sb3135071790101768542287578439snlbxq'|dc

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This archive was generated by hypermail 2b29 : Mon Sep 23 2002 - 22:00:19 EST