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authorHugh Dickins <hugh@veritas.com>2005-10-29 21:16:03 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2005-10-30 00:40:37 -0400
commitfc2acab31be8e869b2d5f6de12f557f6f054f19c (patch)
tree60cf419f5e88c3c46d39675a14649ea1e5849f03
parent4d6ddfa9242bc3d27fb0f7248f6fdee0299c731f (diff)
[PATCH] mm: tlb_finish_mmu forget rss
zap_pte_range has been counting the pages it frees in tlb->freed, then tlb_finish_mmu has used that to update the mm's rss. That got stranger when I added anon_rss, yet updated it by a different route; and stranger when rss and anon_rss became mm_counters with special access macros. And it would no longer be viable if we're relying on page_table_lock to stabilize the mm_counter, but calling tlb_finish_mmu outside that lock. Remove the mmu_gather's freed field, let tlb_finish_mmu stick to its own business, just decrement the rss mm_counter in zap_pte_range (yes, there was some point to batching the update, and a subsequent patch restores that). And forget the anal paranoia of first reading the counter to avoid going negative - if rss does go negative, just fix that bug. Remove the mmu_gather's flushes and avoided_flushes from arm and arm26: no use was being made of them. But arm26 alone was actually using the freed, in the way some others use need_flush: give it a need_flush. arm26 seems to prefer spaces to tabs here: respect that. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/sparc64/mm/tlb.c3
-rw-r--r--include/asm-arm/tlb.h15
-rw-r--r--include/asm-arm26/tlb.h35
-rw-r--r--include/asm-generic/tlb.h9
-rw-r--r--include/asm-ia64/tlb.h9
-rw-r--r--include/asm-sparc64/tlb.h14
-rw-r--r--mm/memory.c2
7 files changed, 18 insertions, 69 deletions
diff --git a/arch/sparc64/mm/tlb.c b/arch/sparc64/mm/tlb.c
index 6a43f7cd090e..8b104be4662b 100644
--- a/arch/sparc64/mm/tlb.c
+++ b/arch/sparc64/mm/tlb.c
@@ -18,8 +18,7 @@
18 18
19/* Heavily inspired by the ppc64 code. */ 19/* Heavily inspired by the ppc64 code. */
20 20
21DEFINE_PER_CPU(struct mmu_gather, mmu_gathers) = 21DEFINE_PER_CPU(struct mmu_gather, mmu_gathers) = { 0, };
22 { NULL, 0, 0, 0, 0, 0, { 0 }, { NULL }, };
23 22
24void flush_tlb_pending(void) 23void flush_tlb_pending(void)
25{ 24{
diff --git a/include/asm-arm/tlb.h b/include/asm-arm/tlb.h
index a35ab0f2e25e..f49bfb78c221 100644
--- a/include/asm-arm/tlb.h
+++ b/include/asm-arm/tlb.h
@@ -27,11 +27,7 @@
27 */ 27 */
28struct mmu_gather { 28struct mmu_gather {
29 struct mm_struct *mm; 29 struct mm_struct *mm;
30 unsigned int freed;
31 unsigned int fullmm; 30 unsigned int fullmm;
32
33 unsigned int flushes;
34 unsigned int avoided_flushes;
35}; 31};
36 32
37DECLARE_PER_CPU(struct mmu_gather, mmu_gathers); 33DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
@@ -42,7 +38,6 @@ tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
42 struct mmu_gather *tlb = &get_cpu_var(mmu_gathers); 38 struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);
43 39
44 tlb->mm = mm; 40 tlb->mm = mm;
45 tlb->freed = 0;
46 tlb->fullmm = full_mm_flush; 41 tlb->fullmm = full_mm_flush;
47 42
48 return tlb; 43 return tlb;
@@ -51,16 +46,8 @@ tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
51static inline void 46static inline void
52tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) 47tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
53{ 48{
54 struct mm_struct *mm = tlb->mm;
55 unsigned long freed = tlb->freed;
56 int rss = get_mm_counter(mm, rss);
57
58 if (rss < freed)
59 freed = rss;
60 add_mm_counter(mm, rss, -freed);
61
62 if (tlb->fullmm) 49 if (tlb->fullmm)
63 flush_tlb_mm(mm); 50 flush_tlb_mm(tlb->mm);
64 51
65 /* keep the page table cache within bounds */ 52 /* keep the page table cache within bounds */
66 check_pgt_cache(); 53 check_pgt_cache();
diff --git a/include/asm-arm26/tlb.h b/include/asm-arm26/tlb.h
index c7d54ca0a239..08ddd85b8d35 100644
--- a/include/asm-arm26/tlb.h
+++ b/include/asm-arm26/tlb.h
@@ -10,11 +10,8 @@
10 */ 10 */
11struct mmu_gather { 11struct mmu_gather {
12 struct mm_struct *mm; 12 struct mm_struct *mm;
13 unsigned int freed; 13 unsigned int need_flush;
14 unsigned int fullmm; 14 unsigned int fullmm;
15
16 unsigned int flushes;
17 unsigned int avoided_flushes;
18}; 15};
19 16
20DECLARE_PER_CPU(struct mmu_gather, mmu_gathers); 17DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
@@ -25,8 +22,8 @@ tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
25 struct mmu_gather *tlb = &get_cpu_var(mmu_gathers); 22 struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);
26 23
27 tlb->mm = mm; 24 tlb->mm = mm;
28 tlb->freed = 0; 25 tlb->need_flush = 0;
29 tlb->fullmm = full_mm_flush; 26 tlb->fullmm = full_mm_flush;
30 27
31 return tlb; 28 return tlb;
32} 29}
@@ -34,20 +31,8 @@ tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
34static inline void 31static inline void
35tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) 32tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
36{ 33{
37 struct mm_struct *mm = tlb->mm; 34 if (tlb->need_flush)
38 unsigned long freed = tlb->freed; 35 flush_tlb_mm(tlb->mm);
39 int rss = get_mm_counter(mm, rss);
40
41 if (rss < freed)
42 freed = rss;
43 add_mm_counter(mm, rss, -freed);
44
45 if (freed) {
46 flush_tlb_mm(mm);
47 tlb->flushes++;
48 } else {
49 tlb->avoided_flushes++;
50 }
51 36
52 /* keep the page table cache within bounds */ 37 /* keep the page table cache within bounds */
53 check_pgt_cache(); 38 check_pgt_cache();
@@ -65,7 +50,13 @@ tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
65 } while (0) 50 } while (0)
66#define tlb_end_vma(tlb,vma) do { } while (0) 51#define tlb_end_vma(tlb,vma) do { } while (0)
67 52
68#define tlb_remove_page(tlb,page) free_page_and_swap_cache(page) 53static inline void
54tlb_remove_page(struct mmu_gather *tlb, struct page *page)
55{
56 tlb->need_flush = 1;
57 free_page_and_swap_cache(page);
58}
59
69#define pte_free_tlb(tlb,ptep) pte_free(ptep) 60#define pte_free_tlb(tlb,ptep) pte_free(ptep)
70#define pmd_free_tlb(tlb,pmdp) pmd_free(pmdp) 61#define pmd_free_tlb(tlb,pmdp) pmd_free(pmdp)
71 62
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 5d352a70f004..cdd4145243cd 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -42,7 +42,6 @@ struct mmu_gather {
42 unsigned int nr; /* set to ~0U means fast mode */ 42 unsigned int nr; /* set to ~0U means fast mode */
43 unsigned int need_flush;/* Really unmapped some ptes? */ 43 unsigned int need_flush;/* Really unmapped some ptes? */
44 unsigned int fullmm; /* non-zero means full mm flush */ 44 unsigned int fullmm; /* non-zero means full mm flush */
45 unsigned long freed;
46 struct page * pages[FREE_PTE_NR]; 45 struct page * pages[FREE_PTE_NR];
47}; 46};
48 47
@@ -63,7 +62,6 @@ tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
63 tlb->nr = num_online_cpus() > 1 ? 0U : ~0U; 62 tlb->nr = num_online_cpus() > 1 ? 0U : ~0U;
64 63
65 tlb->fullmm = full_mm_flush; 64 tlb->fullmm = full_mm_flush;
66 tlb->freed = 0;
67 65
68 return tlb; 66 return tlb;
69} 67}
@@ -88,13 +86,6 @@ tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
88static inline void 86static inline void
89tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) 87tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
90{ 88{
91 int freed = tlb->freed;
92 struct mm_struct *mm = tlb->mm;
93 int rss = get_mm_counter(mm, rss);
94
95 if (rss < freed)
96 freed = rss;
97 add_mm_counter(mm, rss, -freed);
98 tlb_flush_mmu(tlb, start, end); 89 tlb_flush_mmu(tlb, start, end);
99 90
100 /* keep the page table cache within bounds */ 91 /* keep the page table cache within bounds */
diff --git a/include/asm-ia64/tlb.h b/include/asm-ia64/tlb.h
index 0bbd79f6a793..834370b9dea1 100644
--- a/include/asm-ia64/tlb.h
+++ b/include/asm-ia64/tlb.h
@@ -60,7 +60,6 @@ struct mmu_gather {
60 unsigned int nr; /* == ~0U => fast mode */ 60 unsigned int nr; /* == ~0U => fast mode */
61 unsigned char fullmm; /* non-zero means full mm flush */ 61 unsigned char fullmm; /* non-zero means full mm flush */
62 unsigned char need_flush; /* really unmapped some PTEs? */ 62 unsigned char need_flush; /* really unmapped some PTEs? */
63 unsigned long freed; /* number of pages freed */
64 unsigned long start_addr; 63 unsigned long start_addr;
65 unsigned long end_addr; 64 unsigned long end_addr;
66 struct page *pages[FREE_PTE_NR]; 65 struct page *pages[FREE_PTE_NR];
@@ -147,7 +146,6 @@ tlb_gather_mmu (struct mm_struct *mm, unsigned int full_mm_flush)
147 */ 146 */
148 tlb->nr = (num_online_cpus() == 1) ? ~0U : 0; 147 tlb->nr = (num_online_cpus() == 1) ? ~0U : 0;
149 tlb->fullmm = full_mm_flush; 148 tlb->fullmm = full_mm_flush;
150 tlb->freed = 0;
151 tlb->start_addr = ~0UL; 149 tlb->start_addr = ~0UL;
152 return tlb; 150 return tlb;
153} 151}
@@ -159,13 +157,6 @@ tlb_gather_mmu (struct mm_struct *mm, unsigned int full_mm_flush)
159static inline void 157static inline void
160tlb_finish_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long end) 158tlb_finish_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long end)
161{ 159{
162 unsigned long freed = tlb->freed;
163 struct mm_struct *mm = tlb->mm;
164 unsigned long rss = get_mm_counter(mm, rss);
165
166 if (rss < freed)
167 freed = rss;
168 add_mm_counter(mm, rss, -freed);
169 /* 160 /*
170 * Note: tlb->nr may be 0 at this point, so we can't rely on tlb->start_addr and 161 * Note: tlb->nr may be 0 at this point, so we can't rely on tlb->start_addr and
171 * tlb->end_addr. 162 * tlb->end_addr.
diff --git a/include/asm-sparc64/tlb.h b/include/asm-sparc64/tlb.h
index 5d194eae870c..66138d959df5 100644
--- a/include/asm-sparc64/tlb.h
+++ b/include/asm-sparc64/tlb.h
@@ -27,7 +27,6 @@ struct mmu_gather {
27 unsigned int need_flush; 27 unsigned int need_flush;
28 unsigned int fullmm; 28 unsigned int fullmm;
29 unsigned int tlb_nr; 29 unsigned int tlb_nr;
30 unsigned long freed;
31 unsigned long vaddrs[TLB_BATCH_NR]; 30 unsigned long vaddrs[TLB_BATCH_NR];
32 struct page *pages[FREE_PTE_NR]; 31 struct page *pages[FREE_PTE_NR];
33}; 32};
@@ -51,7 +50,6 @@ static inline struct mmu_gather *tlb_gather_mmu(struct mm_struct *mm, unsigned i
51 mp->mm = mm; 50 mp->mm = mm;
52 mp->pages_nr = num_online_cpus() > 1 ? 0U : ~0U; 51 mp->pages_nr = num_online_cpus() > 1 ? 0U : ~0U;
53 mp->fullmm = full_mm_flush; 52 mp->fullmm = full_mm_flush;
54 mp->freed = 0;
55 53
56 return mp; 54 return mp;
57} 55}
@@ -78,19 +76,11 @@ extern void smp_flush_tlb_mm(struct mm_struct *mm);
78 76
79static inline void tlb_finish_mmu(struct mmu_gather *mp, unsigned long start, unsigned long end) 77static inline void tlb_finish_mmu(struct mmu_gather *mp, unsigned long start, unsigned long end)
80{ 78{
81 unsigned long freed = mp->freed;
82 struct mm_struct *mm = mp->mm;
83 unsigned long rss = get_mm_counter(mm, rss);
84
85 if (rss < freed)
86 freed = rss;
87 add_mm_counter(mm, rss, -freed);
88
89 tlb_flush_mmu(mp); 79 tlb_flush_mmu(mp);
90 80
91 if (mp->fullmm) { 81 if (mp->fullmm) {
92 if (CTX_VALID(mm->context)) 82 if (CTX_VALID(mp->mm->context))
93 do_flush_tlb_mm(mm); 83 do_flush_tlb_mm(mp->mm);
94 mp->fullmm = 0; 84 mp->fullmm = 0;
95 } else 85 } else
96 flush_tlb_pending(); 86 flush_tlb_pending();
diff --git a/mm/memory.c b/mm/memory.c
index 585bb4e0b97f..51eb38574830 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -582,7 +582,7 @@ static void zap_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
582 if (pte_young(ptent)) 582 if (pte_young(ptent))
583 mark_page_accessed(page); 583 mark_page_accessed(page);
584 } 584 }
585 tlb->freed++; 585 dec_mm_counter(tlb->mm, rss);
586 page_remove_rmap(page); 586 page_remove_rmap(page);
587 tlb_remove_page(tlb, page); 587 tlb_remove_page(tlb, page);
588 continue; 588 continue;