From: Jason Gunthorpe <jgg@ziepe.ca>
To: David Woodhouse <dwmw2@infradead.org>
Cc: "Michal Hocko" <mhocko@suse.com>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"David Hildenbrand" <david@kernel.org>,
"Lorenzo Stoakes" <ljs@kernel.org>,
"Liam R. Howlett" <liam@infradead.org>,
"Vlastimil Babka" <vbabka@kernel.org>,
"Mike Rapoport" <rppt@kernel.org>,
"Suren Baghdasaryan" <surenb@google.com>,
"Sebastian Andrzej Siewior" <bigeasy@linutronix.de>,
"Clark Williams" <clrkwllms@kernel.org>,
"Simona Vetter" <simona.vetter@ffwll.ch>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Christian König" <christian.koenig@amd.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
"Sean Christopherson" <seanjc@google.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
linux-mm@kvack.org, kvm@vger.kernel.org,
linux-rt-devel@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/mmu_notifier: Remove non_block_start/end() from notifier invocation
Date: Wed, 12 Aug 2026 11:26:59 -0300 [thread overview]
Message-ID: <20260812142659.GD662699@ziepe.ca> (raw)
In-Reply-To: <a48e6e7063122b22a8083bb0792984a204f316e6.camel@infradead.org>
On Wed, Aug 12, 2026 at 03:05:43PM +0100, David Woodhouse wrote:
> the non_block_{start,end} guards around the MMU notifiers, which are
> basically never being called anyway and don't actually seem to protect
> against any real bugs.
If you think this blocked stuff is dead code then lets remove it, but
I'm pretty sure it is called and I remember seeing bug reports about
it being triggered in the wild. Vetter certainly added it because
their tests were actually triggering and they had bugs in their DRM
stack directly connected to this.
It might not trigger for your hypervisor case but we aren't here just
to make only kvm work now are we?
Jason
next prev parent reply other threads:[~2026-08-12 14:27 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-11 8:58 [PATCH] mm/mmu_notifier: Remove non_block_start/end() from notifier invocation David Woodhouse
2026-08-11 13:55 ` Jason Gunthorpe
[not found] ` <1d669aca4ffee797b9c29215382444a5b23624b3.camel@infradead.org>
2026-08-11 14:27 ` Jason Gunthorpe
2026-08-11 14:33 ` David Woodhouse
2026-08-11 14:42 ` Steven Rostedt
2026-08-11 15:24 ` David Woodhouse
2026-08-11 15:30 ` Jason Gunthorpe
2026-08-12 8:14 ` Michal Hocko
2026-08-12 8:21 ` David Woodhouse
2026-08-12 12:27 ` Jason Gunthorpe
2026-08-12 13:46 ` David Woodhouse
2026-08-12 13:49 ` Jason Gunthorpe
2026-08-12 14:05 ` David Woodhouse
2026-08-12 14:26 ` Jason Gunthorpe [this message]
2026-08-12 14:38 ` David Woodhouse
2026-08-12 14:34 ` David Woodhouse
2026-08-12 15:03 ` David Woodhouse
2026-08-12 15:49 ` David Woodhouse
2026-08-12 16:04 ` Paolo Bonzini
2026-08-12 16:07 ` Jason Gunthorpe
2026-08-12 8:13 ` Michal Hocko
2026-08-11 15:29 ` Jason Gunthorpe
2026-08-11 15:15 ` David Woodhouse
2026-08-11 15:24 ` Jason Gunthorpe
2026-08-11 15:29 ` David Woodhouse
2026-08-11 16:24 ` Jason Gunthorpe
2026-08-11 17:22 ` David Woodhouse
2026-08-11 17:26 ` Jason Gunthorpe
2026-08-11 17:59 ` David Woodhouse
2026-08-11 18:19 ` Jason Gunthorpe
2026-08-11 20:06 ` Sean Christopherson
2026-08-11 20:21 ` Paolo Bonzini
2026-08-11 21:14 ` David Woodhouse
2026-08-11 22:58 ` Sean Christopherson
2026-08-11 23:50 ` David Woodhouse
2026-08-12 10:25 ` David Woodhouse
2026-08-12 16:07 ` Sean Christopherson
2026-08-11 20:29 ` David Woodhouse
2026-08-11 15:12 ` David Hildenbrand (Arm)
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