From: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@kernel.org>,
"Liam R . Howlett" <Liam.Howlett@oracle.com>,
Vlastimil Babka <vbabka@suse.cz>, Mike Rapoport <rppt@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
Michal Hocko <mhocko@suse.com>,
Shakeel Butt <shakeel.butt@linux.dev>,
Jann Horn <jannh@google.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-rt-devel@lists.linux.dev, Ingo Molnar <mingo@redhat.com>,
Will Deacon <will@kernel.org>, Boqun Feng <boqun.feng@gmail.com>,
Waiman Long <longman@redhat.com>,
Clark Williams <clrkwllms@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH RESEND 1/3] locking: add rwsem_is_write_locked(), update non-lockdep asserts
Date: Fri, 16 Jan 2026 16:56:09 +0000 [thread overview]
Message-ID: <75459722-0bb9-49a3-82e5-e034307b09e0@lucifer.local> (raw)
In-Reply-To: <20260116164139.8Sm2sJxG@linutronix.de>
On Fri, Jan 16, 2026 at 05:41:39PM +0100, Sebastian Andrzej Siewior wrote:
> On 2026-01-16 16:21:29 [+0000], Lorenzo Stoakes wrote:
> > On Fri, Jan 16, 2026 at 04:57:43PM +0100, Sebastian Andrzej Siewior wrote:
> > > On 2026-01-16 15:50:24 [+0000], Lorenzo Stoakes wrote:
> > > > No, but we need to be able to assert that one of two locks are held and we
> > > > don't want the failure of one being held to cause an assert when the other
> > > > isn't.
> > >
> > > But why don't you use the lockdep based check? That assert only ensures
> >
> > Not sure what you mean, the checks I'm adding don't exist yet.
>
> The checks you add are not lockdep.
I understand that thanks (?)
I'm not sure responding point by point is productive here, so let me
summarise:
We often run code locally without lockdep, testing isn't always ideal
across mm and these asserts are gated by CONFIG_DEBUG_VM anyway so yes I
want a non-lockdep version also.
Note that existing mm lock asserts already work this way, so that's
consistent (though mmap asserts are also at runtime...)
I can't just use existing asserts because I need to test that EITHER one
lock OR the other is held. If there's a way to do that with lockdep in a
way other than what I have suggested, I am more than happy to hear it?
If not I'll respin this with both a lockdep + not-lockdep version.
What you're suggesting, just using the existing lockdep asserts, won't work
unless I'm missing something, because of this _either_ lock requirement.
But if there is an existing solution that you can point me at I'd be more
than happy to use it.
Thanks, Lorenzo
next prev parent reply other threads:[~2026-01-16 16:56 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-16 13:36 [PATCH RESEND 0/3] add and use vma_assert_stabilised() helper Lorenzo Stoakes
2026-01-16 13:36 ` [PATCH RESEND 1/3] locking: add rwsem_is_write_locked(), update non-lockdep asserts Lorenzo Stoakes
2026-01-16 15:08 ` Zi Yan
2026-01-16 16:29 ` Lorenzo Stoakes
2026-01-16 15:12 ` Peter Zijlstra
2026-01-16 15:50 ` Lorenzo Stoakes
2026-01-16 15:57 ` Sebastian Andrzej Siewior
2026-01-16 16:21 ` Lorenzo Stoakes
2026-01-16 16:41 ` Sebastian Andrzej Siewior
2026-01-16 16:56 ` Lorenzo Stoakes [this message]
2026-01-17 2:30 ` Boqun Feng
2026-01-16 13:36 ` [PATCH RESEND 2/3] mm/vma: add vma_is_*_locked() helpers Lorenzo Stoakes
2026-01-16 13:36 ` [PATCH RESEND 3/3] mm: add + use vma_is_stabilised(), vma_assert_stabilised() helpers Lorenzo Stoakes
2026-01-16 20:45 ` Zi Yan
2026-01-16 20:47 ` Zi Yan
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