[PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-25 Thread Rafael J. Wysocki
From: Rafael J. Wysocki There are two mutexes, device_hotplug_lock and acpi_scan_lock, held around the acpi_bus_trim() call in acpi_scan_hot_remove() which generally removes devices (it removes ACPI device objects at least, but it may also remove "physical" device objects through .detach() callba

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-25 Thread Gu Zheng
Hi Rafael, On 08/26/2013 04:09 AM, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > There are two mutexes, device_hotplug_lock and acpi_scan_lock, held > around the acpi_bus_trim() call in acpi_scan_hot_remove() which > generally removes devices (it removes ACPI device objects at least, >

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-26 Thread Rafael J. Wysocki
On Monday, August 26, 2013 11:13:13 AM Gu Zheng wrote: > Hi Rafael, Hi, > On 08/26/2013 04:09 AM, Rafael J. Wysocki wrote: > > > From: Rafael J. Wysocki > > > > There are two mutexes, device_hotplug_lock and acpi_scan_lock, held > > around the acpi_bus_trim() call in acpi_scan_hot_remove() whi

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-26 Thread Rafael J. Wysocki
On Monday, August 26, 2013 02:42:09 PM Rafael J. Wysocki wrote: > On Monday, August 26, 2013 11:13:13 AM Gu Zheng wrote: > > Hi Rafael, > > Hi, > > > On 08/26/2013 04:09 AM, Rafael J. Wysocki wrote: > > > > > From: Rafael J. Wysocki > > > > > > There are two mutexes, device_hotplug_lock and ac

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-26 Thread Rafael J. Wysocki
On Monday, August 26, 2013 04:43:26 PM Rafael J. Wysocki wrote: > On Monday, August 26, 2013 02:42:09 PM Rafael J. Wysocki wrote: > > On Monday, August 26, 2013 11:13:13 AM Gu Zheng wrote: > > > Hi Rafael, [...] > > OK, so the patch below is quick and dirty and overkill, but it should make the >

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-26 Thread Gu Zheng
Hi Rafael, On 08/26/2013 10:43 PM, Rafael J. Wysocki wrote: > On Monday, August 26, 2013 02:42:09 PM Rafael J. Wysocki wrote: >> On Monday, August 26, 2013 11:13:13 AM Gu Zheng wrote: >>> Hi Rafael, >> >> Hi, >> >>> On 08/26/2013 04:09 AM, Rafael J. Wysocki wrote: >>> From: Rafael J. Wysocki

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-26 Thread Gu Zheng
>>> >>> >>>[] device_remove_file+0x17/0x20 >>> >&

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-26 Thread Gu Zheng
Hi Rafael, On 08/26/2013 11:02 PM, Rafael J. Wysocki wrote: > On Monday, August 26, 2013 04:43:26 PM Rafael J. Wysocki wrote: >> On Monday, August 26, 2013 02:42:09 PM Rafael J. Wysocki wrote: >>> On Monday, August 26, 2013 11:13:13 AM Gu Zheng wrote: Hi Rafael, > > [...] > >> >> OK, so th

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-27 Thread Gu Zheng
Hi Rafael, On 08/26/2013 11:02 PM, Rafael J. Wysocki wrote: > On Monday, August 26, 2013 04:43:26 PM Rafael J. Wysocki wrote: >> On Monday, August 26, 2013 02:42:09 PM Rafael J. Wysocki wrote: >>> On Monday, August 26, 2013 11:13:13 AM Gu Zheng wrote: Hi Rafael, > > [...] > >> >> OK, so th

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-27 Thread Tejun Heo
Hello, On Tue, Aug 27, 2013 at 05:21:44PM +0800, Gu Zheng wrote: > >> OK, so the patch below is quick and dirty and overkill, but it should make > >> the > >> splat go away at least. > > > > And if this patch does make the splat go away for you, please also test the > > appended one (Tejun, than

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-27 Thread Rafael J. Wysocki
On Tuesday, August 27, 2013 02:36:44 PM Tejun Heo wrote: > Hello, > > On Tue, Aug 27, 2013 at 05:21:44PM +0800, Gu Zheng wrote: > > >> OK, so the patch below is quick and dirty and overkill, but it should > > >> make the > > >> splat go away at least. > > > > > > And if this patch does make the

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-27 Thread Toshi Kani
On Tue, 2013-08-27 at 17:21 +0800, Gu Zheng wrote: > Hi Rafael, > > On 08/26/2013 11:02 PM, Rafael J. Wysocki wrote: > > > On Monday, August 26, 2013 04:43:26 PM Rafael J. Wysocki wrote: > >> On Monday, August 26, 2013 02:42:09 PM Rafael J. Wysocki wrote: > >>> On Monday, August 26, 2013 11:13:13

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-27 Thread Gu Zheng
Hi Toshi, On 08/28/2013 05:38 AM, Toshi Kani wrote: > On Tue, 2013-08-27 at 17:21 +0800, Gu Zheng wrote: >> Hi Rafael, >> >> On 08/26/2013 11:02 PM, Rafael J. Wysocki wrote: >> >>> On Monday, August 26, 2013 04:43:26 PM Rafael J. Wysocki wrote: On Monday, August 26, 2013 02:42:09 PM Rafael J

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-28 Thread Gu Zheng
Hi Rafael, On 08/28/2013 05:45 AM, Rafael J. Wysocki wrote: > On Tuesday, August 27, 2013 02:36:44 PM Tejun Heo wrote: >> Hello, >> [...] > > I've thought about that a bit over the last several hours and I'm still > thinking that that patch is a bit overkill, because it will trigger the > restar

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-28 Thread Tejun Heo
Hello, Rafael. On Tue, Aug 27, 2013 at 11:45:46PM +0200, Rafael J. Wysocki wrote: > I've thought about that a bit over the last several hours and I'm still > thinking that that patch is a bit overkill, because it will trigger the > restart_syscall() for all cases when device_hotplug_lock is locked

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-28 Thread Rafael J. Wysocki
On Wednesday, August 28, 2013 08:24:22 AM Tejun Heo wrote: > Hello, Rafael. > > On Tue, Aug 27, 2013 at 11:45:46PM +0200, Rafael J. Wysocki wrote: > > I've thought about that a bit over the last several hours and I'm still > > thinking that that patch is a bit overkill, because it will trigger the

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-28 Thread Toshi Kani
On Wed, 2013-08-28 at 10:12 +0800, Gu Zheng wrote: > On 08/28/2013 05:38 AM, Toshi Kani wrote: : > >> > >> What about changing device_hotplug_lock and acpi_scan_lock to rwsem? like > >> the > >> attached one(With a preliminary test, it also can make the splat go > >> away).:) > > > > I am curio

Re: [PATCH] driver core / ACPI: Avoid device removal locking problems

2013-08-25 Thread Greg Kroah-Hartman
On Sun, Aug 25, 2013 at 10:09:47PM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > There are two mutexes, device_hotplug_lock and acpi_scan_lock, held > around the acpi_bus_trim() call in acpi_scan_hot_remove() which > generally removes devices (it removes ACPI device objects at lea