Subject: Re: commit dd4cf8c9e1f4 leads to failed boot

From: "Aithal, Srikanth" <[email-masked]>
Date: Wed, 23 Apr 2025 20:49:08 +0530

On 4/23/2025 7:48 PM, Paul E. McKenney wrote:
> On Wed, Apr 23, 2025 at 07:09:42PM +0530, Aithal, Srikanth wrote:
>> On 4/23/2025 5:24 PM, Bert Karwatzki wrote:
>>> Since linux next-20250422 booting fails on my MSI Alpha 15 Laptop runnning
>>> debian sid. When booting kernel message appear on screen but no messages from
>>> init (systemd). There are also no logs written even thought emergency sync
>>> via magic sysrq works (a message is printed on screen), presumably because
>>> / is not mounted. I bisected this (from 6.15-rc3 to next-20250422) and found
>>> commit dd4cf8c9e1f4 as the first bad commit.
>>> Reverting commit dd4cf8c9e1f4 in next-20250422 fixes the issue.
>>
>>
>> Hello,
>>
>> On AMD platform as well boot failed starting next-20250422, bisecting the
>> issue led me to same commit dd4cf8c9e1f4. I have attached kernel config and
>> logs.
> 
> Thank you all for the bisection and the report!
> 
> Please check out the predecessor of commit dd4cf8c9e1f4 ("ratelimit:
> Force re-initialization when rate-limiting re-enabled"):
> 
> 13fa70e052dd ("ratelimit: Allow zero ->burst to disable ratelimiting")
> 
> Then please apply the patch shown below, and let me know what happens?
> (Yes, I should have split that commit up...)
> 
> 							Thanx, Paul
> 
> ------------------------------------------------------------------------
> 
> diff --git a/lib/ratelimit.c b/lib/ratelimit.c
> index 04f16b8e24575..13ed636642270 100644
> --- a/lib/ratelimit.c
> +++ b/lib/ratelimit.c
> @@ -35,7 +35,7 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func)
>   	unsigned long flags;
>   	int ret;
>   
> -	if (!interval || !burst)
> +	if (interval <= 0 || burst <= 0)
>   		return 1;
>   
>   	/*

I applied above patch on top of 13fa70e052dd ("ratelimit: Allow zero 
->burst to disable ratelimiting") [linux-20250423]. This is fixing the 
boot issue.

Tested-by: Srikanth Aithal <[email-masked]>