Re: [PATCH v3 13/35] lib: add allocation tagging support for memory allocation profiling

Kent Overstreet
2024-02-16T23:26:20Z

On Mon, Feb 12, 2024 at 02:40:12PM -0800, Kees Cook wrote:
> On Mon, Feb 12, 2024 at 01:38:59PM -0800, Suren Baghdasaryan wrote:
> > diff --git a/include/linux/sched.h b/include/linux/sched.h
> > index ffe8f618ab86..da68a10517c8 100644
> > --- a/include/linux/sched.h
> > +++ b/include/linux/sched.h
> > @@ -770,6 +770,10 @@ struct task_struct {
> > unsigned int flags;
> > unsigned int ptrace;
> >
> > +#ifdef CONFIG_MEM_ALLOC_PROFILING
> > + struct alloc_tag *alloc_tag;
> > +#endif
>
> Normally scheduling is very sensitive to having anything early in
> task_struct. I would suggest moving this the CONFIG_SCHED_CORE ifdef
> area.

This is even hotter than the scheduler members; we actually do want it
up front.