From: Jiang Liu <liuj97@gmail.com>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: Don Dutile <ddutile@redhat.com>, Yinghai Lu <yinghai@kernel.org>,
Greg KH <gregkh@linuxfoundation.org>,
Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>,
Jiang Liu <jiang.liu@huawei.com>,
Taku Izumi <izumi.taku@jp.fujitsu.com>,
"Rafael J . Wysocki" <rjw@sisk.pl>,
Yijing Wang <wangyijing@huawei.com>,
Xinwei Hu <huxinwei@huawei.com>,
linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org
Subject: Re: [RFC PATCH v1 06/22] PCI: use a global lock to serialize PCI root bridge hotplug operations
Date: Mon, 17 Sep 2012 23:51:22 +0800 [thread overview]
Message-ID: <505746FA.5030904@gmail.com> (raw)
In-Reply-To: <CAErSpo4=cakjCQ_Z_nUa2xZQr9KV72kxtsgrW0cjeFN=ktb8zQ@mail.gmail.com>
>>> I'm not sure why you didn't add a pci_host_bridge_hotplug_lock() in
>>> the sba_init() path, since it looks similar to the drm_open_helper()
>>> path above. But in any case, I think that would be the wrong thing to
>>> do because it would fix the superficial problem while leaving the
>>> deeper problem of host bridge hot-add not setting the iommu pointer.
>
>> sba_init is called during system initialization stages through subsys_initcall,
>> so no extra protection for it.
>
> OK, I see your reasoning. But I don't agree :) All the users of an
> interface should use the same locking scheme, even if they're at
> boot-time where we "know" we don't need it. It's too hard to analyze
> differences, and code gets copied from one place to somewhere else
> where it might not be appropriate.
Hi Bjorn,
"All the users of an interface should use the same locking scheme", a really
good design pattern to follow. It's so easy for everybody to remove the __init
modifier without noticing the design limitation.
--Gerry
next prev parent reply other threads:[~2012-09-17 15:51 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-07 16:10 [RFC PATCH v1 00/22] introduce PCI bus lock to serialize PCI hotplug operations Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 01/22] PCI: use pci_get_domain_bus_and_slot() to avoid race conditions Jiang Liu
2012-09-11 22:00 ` Bjorn Helgaas
2012-09-12 8:37 ` Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 02/22] PCI: trivial cleanups for drivers/pci/remove.c Jiang Liu
2012-09-11 22:03 ` Bjorn Helgaas
2012-09-12 8:50 ` Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 03/22] PCI: change PCI device management code to better follow device model Jiang Liu
2012-09-11 22:03 ` Bjorn Helgaas
2012-08-07 16:10 ` [RFC PATCH v1 04/22] PCI: split PCI bus device registration into two stages Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 05/22] PCI: introduce pci_bus_{get|put}() to manage PCI bus reference count Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 06/22] PCI: use a global lock to serialize PCI root bridge hotplug operations Jiang Liu
2012-09-11 22:57 ` Bjorn Helgaas
2012-09-12 15:42 ` Jiang Liu
2012-09-12 16:51 ` Bjorn Helgaas
2012-09-13 16:00 ` [PATCH 1/2] PCI: introduce root bridge hotplug safe interfaces to walk root buses Jiang Liu
2012-09-13 17:40 ` Bjorn Helgaas
2012-09-17 15:55 ` Jiang Liu
2012-09-17 16:24 ` Bjorn Helgaas
2012-09-18 21:39 ` Bjorn Helgaas
2012-09-21 16:07 ` [PATCH v4] PCI: introduce two interfaces to walk PCI buses Jiang Liu
2012-09-26 20:14 ` Bjorn Helgaas
2012-09-13 16:00 ` [PATCH 2/2] PCI: remove host bridge hotplug unsafe interface pci_get_next_bus() Jiang Liu
2012-09-17 15:51 ` Jiang Liu [this message]
2012-09-20 18:49 ` [RFC PATCH v1 06/22] PCI: use a global lock to serialize PCI root bridge hotplug operations Paul E. McKenney
2012-08-07 16:10 ` [RFC PATCH v1 07/22] PCI: introduce PCI bus lock to serialize PCI " Jiang Liu
2012-09-11 23:24 ` Bjorn Helgaas
2012-08-07 16:10 ` [RFC PATCH v1 08/22] PCI: introduce hotplug safe search interfaces for PCI bus/device Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 09/22] PCI: enhance PCI probe logic to support PCI bus lock mechanism Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 10/22] PCI: enhance PCI bus specific " Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 11/22] PCI: enhance PCI resource assignment " Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 12/22] PCI: enhance PCI remove " Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 13/22] PCI: make each PCI device hold a reference to its parent PCI bus Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 14/22] PCI/sysfs: use PCI bus lock to avoid race conditions Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 15/22] PCI/eeepc: " Jiang Liu
2012-09-11 23:18 ` Bjorn Helgaas
2012-09-12 14:24 ` [PATCH] eeepc-laptop: fix device reference count leakage in eeepc_rfkill_hotplug() Jiang Liu
2012-09-12 19:59 ` Bjorn Helgaas
2012-08-07 16:10 ` [RFC PATCH v1 16/22] PCI/asus-wmi: use PCI bus lock to avoid race conditions Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 17/22] PCI/pciehp: " Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 18/22] PCI/acpiphp: " Jiang Liu
2012-08-07 16:10 ` [RFC PATCH v1 19/22] PCI/x86: enable PCI bus lock mechanism for x86 platforms Jiang Liu
2012-09-11 23:22 ` Bjorn Helgaas
2012-09-12 9:56 ` Jiang Liu
2012-08-07 16:11 ` [RFC PATCH v1 20/22] PCI/IA64: enable PCI bus lock mechanism for IA64 platforms Jiang Liu
2012-08-07 16:11 ` [RFC PATCH v1 21/22] PCI: cleanups for PCI bus lock implementation Jiang Liu
2012-09-11 23:21 ` Bjorn Helgaas
2012-09-12 8:58 ` Jiang Liu
2012-08-07 16:11 ` [RFC PATCH v1 22/22] PCI: unexport pci_root_buses Jiang Liu
2012-08-07 18:11 ` [RFC PATCH v1 00/22] introduce PCI bus lock to serialize PCI hotplug operations Don Dutile
2012-08-08 15:49 ` Jiang Liu
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