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

[Steven Rostedt]

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.

I'm curious to what was broken. Just the user space side? Or was the kernel
side broken too?

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