From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Michael Ellerman <mpe@ellerman.id.au>, Qian Cai <cai@redhat.com>
Cc: Oliver O'Halloran <oohall@gmail.com>,
linuxppc-dev@lists.ozlabs.org, Paul Mackerras <paulus@samba.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] powerpc/eeh_cache: Fix a possible debugfs deadlock
Date: Wed, 4 Nov 2020 22:38:30 +1100 (AEDT) [thread overview]
Message-ID: <160448988321.674824.1925161464513848358.b4-ty@ellerman.id.au> (raw)
In-Reply-To: <20201028152717.8967-1-cai@redhat.com>
On Wed, 28 Oct 2020 11:27:17 -0400, Qian Cai wrote:
> Lockdep complains that a possible deadlock below in
> eeh_addr_cache_show() because it is acquiring a lock with IRQ enabled,
> but eeh_addr_cache_insert_dev() needs to acquire the same lock with IRQ
> disabled. Let's just make eeh_addr_cache_show() acquire the lock with
> IRQ disabled as well.
>
> CPU0 CPU1
> ---- ----
> lock(&pci_io_addr_cache_root.piar_lock);
> local_irq_disable();
> lock(&tp->lock);
> lock(&pci_io_addr_cache_root.piar_lock);
> <Interrupt>
> lock(&tp->lock);
>
> [...]
Applied to powerpc/fixes.
[1/1] powerpc/eeh_cache: Fix a possible debugfs deadlock
https://git.kernel.org/powerpc/c/fd552e0542b4532483289cce48fdbd27b692984b
cheers
WARNING: multiple messages have this Message-ID (diff)
From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Michael Ellerman <mpe@ellerman.id.au>, Qian Cai <cai@redhat.com>
Cc: linuxppc-dev@lists.ozlabs.org,
Oliver O'Halloran <oohall@gmail.com>,
linux-kernel@vger.kernel.org, Paul Mackerras <paulus@samba.org>
Subject: Re: [PATCH] powerpc/eeh_cache: Fix a possible debugfs deadlock
Date: Wed, 4 Nov 2020 22:38:30 +1100 (AEDT) [thread overview]
Message-ID: <160448988321.674824.1925161464513848358.b4-ty@ellerman.id.au> (raw)
In-Reply-To: <20201028152717.8967-1-cai@redhat.com>
On Wed, 28 Oct 2020 11:27:17 -0400, Qian Cai wrote:
> Lockdep complains that a possible deadlock below in
> eeh_addr_cache_show() because it is acquiring a lock with IRQ enabled,
> but eeh_addr_cache_insert_dev() needs to acquire the same lock with IRQ
> disabled. Let's just make eeh_addr_cache_show() acquire the lock with
> IRQ disabled as well.
>
> CPU0 CPU1
> ---- ----
> lock(&pci_io_addr_cache_root.piar_lock);
> local_irq_disable();
> lock(&tp->lock);
> lock(&pci_io_addr_cache_root.piar_lock);
> <Interrupt>
> lock(&tp->lock);
>
> [...]
Applied to powerpc/fixes.
[1/1] powerpc/eeh_cache: Fix a possible debugfs deadlock
https://git.kernel.org/powerpc/c/fd552e0542b4532483289cce48fdbd27b692984b
cheers
next prev parent reply other threads:[~2020-11-04 11:38 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-28 15:27 [PATCH] powerpc/eeh_cache: Fix a possible debugfs deadlock Qian Cai
2020-10-28 15:27 ` Qian Cai
2020-10-29 5:57 ` Oliver O'Halloran
2020-10-29 5:57 ` Oliver O'Halloran
2020-11-04 11:38 ` Michael Ellerman [this message]
2020-11-04 11:38 ` Michael Ellerman
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