[PATCH] kdump: print a message in case crashkernel size parsing resulted in zero bytes
Bhupesh Sharma
bhsharma at redhat.com
Mon Nov 13 00:49:54 PST 2017
Hi Dave,
Cc: arm kernel mailing list for wider distribution
On 11/13/2017 11:13 AM, Dave Young wrote:
> In parse_crashkernel_mem, it silently return in case we get zero
> bytes in the parsing function. It is useful for debugging for
> adding a warning message especially sometimes kernel can not boot
> up correctly.
>
> Signed-off-by: Dave Young <dyoung at redhat.com>
> ---
> kernel/crash_core.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> --- linux-x86.orig/kernel/crash_core.c
> +++ linux-x86/kernel/crash_core.c
> @@ -108,7 +108,8 @@ static int __init parse_crashkernel_mem(
> return -EINVAL;
> }
> }
> - }
> + } else
> + pr_warn("crashkernel size resulted in zero bytes\n");
>
> return 0;
> }
>
This is a useful change as finding this debug message in the boot logs allows better debug of crashkernel related issues.
However I have one minor point:
- The comment above 'parse_crashkernel_mem' currently mentions:
* The function returns 0 on success and -EINVAL on failure.
*/
- I am wondering if we hit the WARNING case where the crashkernel size resulted in 0 bytes, then should we still be returning 0 from this function. Or, should this be replaced with 'return -EINVAL'.
- If not, can we atleast update the comment above this function to better document the return values and where having a 'return 0' should be ok, even if crashkernel size resulted in 0 bytes.
Regards,
Bhupesh
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