Re: [PATCH v4 1/5] mm: Provide kernel parameter to allow disabling page init poisoning

[Pasha Tatashin]

On 9/21/18 3:41 PM, Logan Gunthorpe wrote:
> On 2018-09-21 1:04 PM, Pasha Tatashin wrote:
>>
>>> +			pr_err("vm_debug option '%c' unknown. skipped\n",
>>> +			       *str);
>>> +		}
>>> +
>>> +		str++;
>>> +	}
>>> +out:
>>> +	if (page_init_poisoning && !__page_init_poisoning)
>>> +		pr_warn("Page struct poisoning disabled by kernel command line option 'vm_debug'\n");
>>
>> New lines '\n' can be removed, they are not needed for kprintfs.
> 
> No, that's not correct.
> 
> A printk without a newline termination is not emitted
> as output until the next printk call. (To support KERN_CONT).
> Therefore removing the '\n' causes a printk to not be printed when it is
> called which can cause long delayed messages and subtle problems when
> debugging. Always keep the newline in place even though the kernel will
> add one for you if it's missing.

OK. Thank you for clarifying Logan. I've seen new lines are being
removed in other patches,

Pavel