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

[Baoquan He]

Hi Atsushi,

I have got the test machine where bug reported and did a test. The
changed code can make elf dump successful.

Thanks
Baoquan


On 04/14/14 at 04:02pm, Baoquan He wrote:
> 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
> 
> 
> _______________________________________________
> kexec mailing list
> kexec at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec