[PATCH 2/2] Git rid of overrun adjustments
Petr Tesarik
ptesarik at suse.cz
Fri Apr 4 05:56:09 EDT 2014
Thanks to the previous commit, __exclude_unnecessary_pages does not
require any specific size of the cycle.
Signed-off-by: Petr Tesarik <ptesarik at suse.cz>
---
makedumpfile.c | 59 ----------------------------------------------------------
1 file changed, 59 deletions(-)
diff --git a/makedumpfile.c b/makedumpfile.c
index 61ee886..2a5458b 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -88,7 +88,6 @@ do { \
*ptr_long_table = value; \
} while (0)
-static void check_cyclic_buffer_overrun(void);
static void setup_page_is_buddy(void);
void
@@ -3251,9 +3250,6 @@ out:
!sadump_generate_elf_note_from_dumpfile())
return FALSE;
- if (info->flag_cyclic && info->dump_level & DL_EXCLUDE_FREE)
- check_cyclic_buffer_overrun();
-
} else {
if (!get_mem_map_without_mm())
return FALSE;
@@ -4271,61 +4267,6 @@ exclude_free_page(struct cycle *cycle)
}
/*
- * Let C be a cyclic buffer size and B a bitmap size used for
- * representing maximum block size managed by buddy allocator.
- *
- * For some combinations of C and B, clearing operation can overrun
- * the cyclic buffer. Let's consider three cases.
- *
- * - If C == B, this is trivially safe.
- *
- * - If B > C, overrun can easily happen.
- *
- * - In case of C > B, if C mod B != 0, then there exist n > m > 0,
- * B > b > 0 such that n x C = m x B + b. This means that clearing
- * operation overruns cyclic buffer (B - b)-bytes in the
- * combination of n-th cycle and m-th block.
- *
- * Note that C mod B != 0 iff (m x C) mod B != 0 for some m.
- *
- * If C == B, C mod B == 0 always holds. Again, if B > C, C mod B != 0
- * always holds. Hence, it's always sufficient to check the condition
- * C mod B != 0 in order to determine whether overrun can happen or
- * not.
- *
- * The bitmap size used for maximum block size B is calculated from
- * MAX_ORDER as:
- *
- * B := DIVIDE_UP((1 << (MAX_ORDER - 1)), BITS_PER_BYTE)
- *
- * Normally, MAX_ORDER is 11 at default. This is configurable through
- * CONFIG_FORCE_MAX_ZONEORDER.
- */
-static void
-check_cyclic_buffer_overrun(void)
-{
- int max_order = ARRAY_LENGTH(zone.free_area);
- int max_order_nr_pages = 1 << (max_order - 1);
- unsigned long max_block_size = divideup(max_order_nr_pages, BITPERBYTE);
-
- if (info->bufsize_cyclic % max_block_size) {
- unsigned long bufsize;
-
- if (max_block_size > info->bufsize_cyclic) {
- MSG("WARNING: some free pages are not filtered.\n");
- return;
- }
-
- bufsize = info->bufsize_cyclic;
- info->bufsize_cyclic = round(bufsize, max_block_size);
- info->pfn_cyclic = info->bufsize_cyclic * BITPERBYTE;
-
- MSG("cyclic buffer size has been changed: %lu => %lu\n",
- bufsize, info->bufsize_cyclic);
- }
-}
-
-/*
* For the kernel versions from v2.6.17 to v2.6.37.
*/
static int
--
1.8.4.5
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