Re: [PATCH 2/3] mm: Extract might_alloc() debug check

From: Daniel Vetter <daniel.vetter@ffwll.ch>
To: Randy Dunlap <rdunlap@infradead.org>
Cc: DRI Development <dri-devel@lists.freedesktop.org>,
	Intel Graphics Development <intel-gfx@lists.freedesktop.org>,
	Linux MM <linux-mm@kvack.org>,
	linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>,
	Vlastimil Babka <vbabka@suse.cz>,
	"Paul E . McKenney" <paulmck@kernel.org>,
	Christoph Lameter <cl@linux.com>,
	Pekka Enberg <penberg@kernel.org>,
	David Rientjes <rientjes@google.com>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	Michel Lespinasse <walken@google.com>,
	Waiman Long <longman@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Dave Chinner <david@fromorbit.com>, Qian Cai <cai@lca.pw>,
	"Matthew Wilcox (Oracle)" <willy@infradead.org>,
	Daniel Vetter <daniel.vetter@intel.com>
Subject: Re: [PATCH 2/3] mm: Extract might_alloc() debug check
Date: Fri, 20 Nov 2020 18:31:41 +0100	[thread overview]
Message-ID: <CAKMK7uH1NAU1KLNzeYeB=Ri9S8A9UGcHSufh5iCtwUoTChvP2A@mail.gmail.com> (raw)
In-Reply-To: <bfe3b1a4-9cc0-358f-a62e-b6d9a68e735a@infradead.org>

On Fri, Nov 20, 2020 at 6:20 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>
> Hi,
>
> On 11/20/20 1:54 AM, Daniel Vetter wrote:
> > diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
> > index d5ece7a9a403..f94405d43fd1 100644
> > --- a/include/linux/sched/mm.h
> > +++ b/include/linux/sched/mm.h
> > @@ -180,6 +180,22 @@ static inline void fs_reclaim_acquire(gfp_t gfp_mask) { }
> >  static inline void fs_reclaim_release(gfp_t gfp_mask) { }
> >  #endif
> >
> > +/**
> > + * might_alloc - Marks possible allocation sites
>
>                     Mark
>
> > + * @gfp_mask: gfp_t flags that would be use to allocate
>
>                                            used
>
> > + *
> > + * Similar to might_sleep() and other annotations this can be used in functions
>
>                                          annotations,
>
> > + * that might allocate, but often dont. Compiles to nothing without
>
>                                      don't.
>
> > + * CONFIG_LOCKDEP. Includes a conditional might_sleep() if @gfp allows blocking.
>
> ?                                            might_sleep_if() if

That's one if too many, I'll do the others for next round. Thanks for
taking a look.
-Daniel

>
> > + */
> > +static inline void might_alloc(gfp_t gfp_mask)
> > +{
> > +     fs_reclaim_acquire(gfp_mask);
> > +     fs_reclaim_release(gfp_mask);
> > +
> > +     might_sleep_if(gfpflags_allow_blocking(gfp_mask));
> > +}
>
>
> --
> ~Randy
>


-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch