From: Guangbo Cui <jckeep.cuiguangbo@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Clark Williams <clrkwllms@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
Boqun Feng <boqun.feng@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Bjorn Helgaas <bhelgaas@google.com>,
Waiman Long <longman@redhat.com>,
linux-rt-devel@lists.linux.dev, linux-kernel@vger.kernel.org,
linux-pci@vger.kernel.org
Subject: Re: [PATCH v4 2/2] PCI/aer_inject: Convert inject_lock to raw_spinlock_t
Date: Thu, 6 Nov 2025 13:08:22 +0000 [thread overview]
Message-ID: <aQydxtOtgPTPxL_9@2a2a0ba7cec8> (raw)
In-Reply-To: <20251103192709.GV1386988@noisy.programming.kicks-ass.net>
On Mon, Nov 03, 2025 at 08:27:09PM +0100, Peter Zijlstra wrote:
> On Mon, Nov 03, 2025 at 08:21:20PM +0100, Peter Zijlstra wrote:
> > On Sun, Nov 02, 2025 at 10:57:06AM +0000, Guangbo Cui wrote:
> > > The AER injection path may run in interrupt-disabled context while
> > > holding inject_lock. On PREEMPT_RT kernels, spinlock_t becomes a
> > > sleeping lock, so it must not be taken while a raw_spinlock_t is held.
> > > Doing so violates lock ordering rules and trigger lockdep reports
> > > such as “Invalid wait context”.
> > >
> > > Convert inject_lock to raw_spinlock_t to ensure non-sleeping locking
> > > semantics. The protected list is bounded and used only for debugging,
> > > so raw locking will not cause latency issues.
> >
> > Bounded how?
> >
> + scoped_guard (raw_spinlock_irqsave, &inject_lock) {
> + if (ops == &aer_inj_pci_ops)
> + break;
> + pci_bus_ops_init(bus_ops, bus, ops);
> + list_add(&bus_ops->list, &pci_bus_ops_list);
> + bus_ops = NULL;
> + }
I found that there are two styles of calling scoped_guard in the kernel:
1. scoped_guard (...)
2. scoped_guard(...)
Is there any coding convention or guideline regarding this?
> + rperr->root_status |= PCI_ERR_ROOT_COR_RCV;
> + rperr->source_id &= 0xffff0000;
> + rperr->source_id |= PCI_DEVID(einj->bus, devfn);
> + }
> + if (einj->uncor_status) {
> + if (rperr->root_status & PCI_ERR_ROOT_UNCOR_RCV)
> + rperr->root_status |= PCI_ERR_ROOT_MULTI_UNCOR_RCV;
> + if (sever & einj->uncor_status) {
> + rperr->root_status |= PCI_ERR_ROOT_FATAL_RCV;
> + if (!(rperr->root_status & PCI_ERR_ROOT_UNCOR_RCV))
> + rperr->root_status |= PCI_ERR_ROOT_FIRST_FATAL;
> + } else
> + rperr->root_status |= PCI_ERR_ROOT_NONFATAL_RCV;
> + rperr->root_status |= PCI_ERR_ROOT_UNCOR_RCV;
> + rperr->source_id &= 0x0000ffff;
> + rperr->source_id |= PCI_DEVID(einj->bus, devfn) << 16;
> + }
> }
> - raw_spin_unlock_irqrestore(&inject_lock, flags);
>
> if (aer_mask_override) {
> pci_write_config_dword(dev, pos_cap_err + PCI_ERR_COR_MASK,
LGTM, If there are no objections, I’ll include these two patches in the
next version of the patchset and add your Signed-off-by tag.
Best regards,
Guangbo
next prev parent reply other threads:[~2025-11-06 13:08 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-02 10:57 [PATCH v4 0/2] PCI/aer_inject: Adjust locking for PREEMPT_RT Guangbo Cui
2025-11-02 10:57 ` [PATCH v4 1/2] PCI/aer_inject: Remove unnecessary lock in aer_inject_exit Guangbo Cui
2025-11-02 10:57 ` [PATCH v4 2/2] PCI/aer_inject: Convert inject_lock to raw_spinlock_t Guangbo Cui
2025-11-03 19:21 ` Peter Zijlstra
2025-11-03 19:27 ` Peter Zijlstra
2025-11-06 13:08 ` Guangbo Cui [this message]
2025-11-06 14:05 ` Peter Zijlstra
2025-11-11 14:39 ` Sebastian Andrzej Siewior
2025-11-03 20:02 ` Sebastian Andrzej Siewior
2025-11-03 20:29 ` Peter Zijlstra
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