Doug / smarc-fsl-linux-kernel

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Commit 51726b1222863852c46ca21ed0115b85d1edfd89

Authored by Hugh Dickins
Committed by Linus Torvalds
1 parent 6d91add09f
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

mm: replace some BUG_ONs by VM_BUG_ONs 

The swap code is over-provisioned with BUG_ONs on assorted page flags,
mostly dating back to 2.3.  They're good documentation, and guard against
developer error, but a waste of space on most systems: change them to
VM_BUG_ONs, conditional on CONFIG_DEBUG_VM.  Just delete the PagePrivate
ones: they're later, from 2.5.69, but even less interesting now.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 3 changed files with 14 additions and 17 deletions Side-by-side Diff

... ... @@ -125,8 +125,8 @@
125 125 struct bio *bio;
126 126 int ret = 0;
127 127  
128   - BUG_ON(!PageLocked(page));
129   - BUG_ON(PageUptodate(page));
  128 + VM_BUG_ON(!PageLocked(page));
  129 + VM_BUG_ON(PageUptodate(page));
130 130 bio = get_swap_bio(GFP_KERNEL, page_private(page), page,
131 131 end_swap_bio_read);
132 132 if (bio == NULL) {
... ... @@ -72,10 +72,10 @@
72 72 {
73 73 int error;
74 74  
75   - BUG_ON(!PageLocked(page));
76   - BUG_ON(PageSwapCache(page));
77   - BUG_ON(PagePrivate(page));
78   - BUG_ON(!PageSwapBacked(page));
  75 + VM_BUG_ON(!PageLocked(page));
  76 + VM_BUG_ON(PageSwapCache(page));
  77 + VM_BUG_ON(!PageSwapBacked(page));
  78 +
79 79 error = radix_tree_preload(gfp_mask);
80 80 if (!error) {
81 81 page_cache_get(page);
... ... @@ -108,10 +108,9 @@
108 108 */
109 109 void __delete_from_swap_cache(struct page *page)
110 110 {
111   - BUG_ON(!PageLocked(page));
112   - BUG_ON(!PageSwapCache(page));
113   - BUG_ON(PageWriteback(page));
114   - BUG_ON(PagePrivate(page));
  111 + VM_BUG_ON(!PageLocked(page));
  112 + VM_BUG_ON(!PageSwapCache(page));
  113 + VM_BUG_ON(PageWriteback(page));
115 114  
116 115 radix_tree_delete(&swapper_space.page_tree, page_private(page));
117 116 set_page_private(page, 0);
... ... @@ -134,8 +133,8 @@
134 133 swp_entry_t entry;
135 134 int err;
136 135  
137   - BUG_ON(!PageLocked(page));
138   - BUG_ON(!PageUptodate(page));
  136 + VM_BUG_ON(!PageLocked(page));
  137 + VM_BUG_ON(!PageUptodate(page));
139 138  
140 139 for (;;) {
141 140 entry = get_swap_page();
... ... @@ -333,7 +333,7 @@
333 333 {
334 334 int count;
335 335  
336   - BUG_ON(!PageLocked(page));
  336 + VM_BUG_ON(!PageLocked(page));
337 337 count = page_mapcount(page);
338 338 if (count <= 1 && PageSwapCache(page))
339 339 count += page_swapcount(page);
... ... @@ -350,8 +350,7 @@
350 350 struct swap_info_struct * p;
351 351 swp_entry_t entry;
352 352  
353   - BUG_ON(PagePrivate(page));
354   - BUG_ON(!PageLocked(page));
  353 + VM_BUG_ON(!PageLocked(page));
355 354  
356 355 if (!PageSwapCache(page))
357 356 return 0;
... ... @@ -432,7 +431,6 @@
432 431 if (page) {
433 432 int one_user;
434 433  
435   - BUG_ON(PagePrivate(page));
436 434 one_user = (page_count(page) == 2);
437 435 /* Only cache user (+us), or swap space full? Free it! */
438 436 /* Also recheck PageSwapCache after page is locked (above) */
... ... @@ -1209,7 +1207,7 @@
1209 1207 {
1210 1208 struct backing_dev_info *bdi;
1211 1209  
1212   - BUG_ON(!PageLocked(page)); /* It pins the swap_info_struct */
  1210 + VM_BUG_ON(!PageLocked(page)); /* It pins the swap_info_struct */
1213 1211  
1214 1212 if (PageSwapCache(page)) {
1215 1213 swp_entry_t entry = { .val = page_private(page) };