From: Jason Gunthorpe <jgg@ziepe.ca>
To: David Woodhouse <dwmw2@infradead.org>
Cc: "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>,
"Michal Hocko" <mhocko@suse.com>,
"Sebastian Andrzej Siewior" <bigeasy@linutronix.de>,
"Clark Williams" <clrkwllms@kernel.org>,
"Steven Rostedt" <rostedt@goodmis.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: Tue, 11 Aug 2026 12:29:14 -0300 [thread overview]
Message-ID: <20260811152914.GI544626@ziepe.ca> (raw)
In-Reply-To: <a552b227e18ddbb3fa1f2edf2d1cb30ee6ccff13.camel@infradead.org>
On Tue, Aug 11, 2026 at 03:33:18PM +0100, David Woodhouse wrote:
> > At the cost of completely destroying the mm shootdown performance with
> > 1s RCU grace period waits every mm operation. No thanks.
>
> I feel like we're not talking about the same things here.
>
> The KVM patch which this enables does *not* behave as you have
> described. Have you looked at it?
It does, it calls synchronize_rcu() from
kvm_mmu_notifier_invalidate_range_start() - don't do that...
> Nobody's suggesting that we force any *other* MMU notifiers to do
> anything that they don't do today.
Sure, but nobody should implement their own notifiers with such a
heavy locking primitive.
Jason
next prev parent reply other threads:[~2026-08-11 15:29 UTC|newest]
Thread overview: 21+ 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
2026-08-11 14:21 ` David Woodhouse
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
2026-08-11 15:29 ` Jason Gunthorpe [this message]
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 20:29 ` David Woodhouse
2026-08-11 15:12 ` David Hildenbrand (Arm)
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