Re: [PATCH v14 11/13] x86/mm: do targeted broadcast flushing from tlbbatch code

[Brendan Jackman]

On Mon, Mar 03, 2025 at 01:47:42PM -0800, Dave Hansen wrote:
> >  static void broadcast_tlb_flush(struct flush_tlb_info *info)
> >  {
> >  	bool pmd = info->stride_shift == PMD_SHIFT;
> > @@ -790,6 +821,8 @@ void switch_mm_irqs_off(struct mm_struct *unused, struct mm_struct *next,
> >  	if (IS_ENABLED(CONFIG_PROVE_LOCKING))
> >  		WARN_ON_ONCE(!irqs_disabled());
> >  
> > +	tlbsync();
> 
> This one is in dire need of comments.

I have been advocating to move this to a place where it's clearer. I
also think it needs comments:

https://lore.kernel.org/all/CA+i-1C31TrceZiizC_tng_cc-zcvKsfXLAZD_XDftXnp9B2Tdw@xxxxxxxxxxxxxx/