Re: [PATCH v2 2/2] sched/numa: Add tracepoint that tracks the skipping of numa balancing due to cpuset memory pinning

[Libo Chen]

On 3/28/25 15:28, Libo Chen wrote:
> 
> 
> On 3/27/25 07:03, Steven Rostedt wrote:
>> On Wed, 26 Mar 2025 21:32:32 -0700
>> Libo Chen <libo.chen@xxxxxxxxxx> wrote:
>>
>>> On 3/26/25 19:06, Steven Rostedt wrote:
>>>> On Wed, 26 Mar 2025 17:40:02 -0700
>>>> Libo Chen <libo.chen@xxxxxxxxxx> wrote:
>>>>   
>>>>>> +	TP_printk("comm=%s pid=%d tgid=%d ngid=%d mem_node_allowed_mask=%lx",    
>>>>>
>>>>>
>>>>> I cannot find a way to print out nodemask_t nicely here with %*pbl.
>>>>> So I fall back to just raw hex value. Will be grateful if someone
>>>>> knows a better way to print nodemask nicely in a tracepoint    
>>>>
>>>> Ug.
>>>>
>>>> I guess I need to add support for that. Both in the boot verifier as well
>>>> as in libtraceevent.
>>>>   
>>>
>>> That will be fantastic, I think this is quite useful.
>>
> 
> Oops just saw this right now, not sure how I missed it.
>  
>> I'm curious to what was broken. Just the user space side? Or was the kernel
>> side broken too?
>>
> 
> That's a good point, I originally only tried %*pbl with trace-cmd, but I
> tested your patch without trace-cmd. So yeah %*pbl may already be working in
> the kernel, I will report back later today.
> 
> -- Libo
> 

Okay yes, it does prints out to trace log. Not seeing the output is due to the
userspace tool not the lack of check. 

-- Libo

>> I notice that i2c_write has "[%*phD]" which means it worked, and also
>> skipped out on the verification tests. This should be fixed.
>>
>> But trace-cmd and perf will not be able to print that out either.
>>
>> Now %*pbl works in the kernel (not checked), but probably doesn't work for
>> trace-cmd.
>>
>> -- Steve
>