[PATCH] makedumpfile: change the wrong code to calculate bufsize_cyclic for elf dump

[Baoquan He]

In case elf dump, the code to calculate the cyclic buffer size is
not correct. Since elf need bitmap1/2, so the needed memory for
bufsize_cyclic need be double. Hence free size should be 40% of
free memory, however the needed_size which free_size is compared
with should be info->max_mapnr / BITPERBYTE, but not 2 times of it.

Because of this, in case of free memory in 2nd kernel is not too much,
OOM will happen very often.

Signed-off-by: Baoquan He <bhe at redhat.com>
---
 makedumpfile.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/makedumpfile.c b/makedumpfile.c
index 75092a8..01ec516 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -9010,7 +9010,7 @@ calculate_cyclic_buffer_size(void) {
 	 */
 	if (info->flag_elf_dumpfile) {
 		free_size = get_free_memory_size() * 0.4;
-		needed_size = (info->max_mapnr * 2) / BITPERBYTE;
+		needed_size = info->max_mapnr / BITPERBYTE;
 	} else {
 		free_size = get_free_memory_size() * 0.8;
 		needed_size = info->max_mapnr / BITPERBYTE;
-- 
1.8.5.3