Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757170Ab3EAUdG (ORCPT ); Wed, 1 May 2013 16:33:06 -0400 Received: from g6t0186.atlanta.hp.com ([15.193.32.63]:6852 "EHLO g6t0186.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755278Ab3EAUdD (ORCPT ); Wed, 1 May 2013 16:33:03 -0400 Message-ID: <1367439612.16154.166.camel@misato.fc.hp.com> Subject: Re: [PATCH 3/3 RFC] ACPI / hotplug: Use device offline/online for graceful hot-removal From: Toshi Kani To: "Rafael J. Wysocki" Cc: Greg Kroah-Hartman , ACPI Devel Maling List , LKML , isimatu.yasuaki@jp.fujitsu.com, vasilis.liaskovitis@profitbricks.com Date: Wed, 01 May 2013 14:20:12 -0600 In-Reply-To: <1513537.Pdbg9h7lkq@vostro.rjw.lan> References: <1576321.HU0tZ4cGWk@vostro.rjw.lan> <2740694.MNypEzdXxd@vostro.rjw.lan> <1367365778.16154.144.camel@misato.fc.hp.com> <1513537.Pdbg9h7lkq@vostro.rjw.lan> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4 (3.6.4-3.fc18) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3388 Lines: 80 On Wed, 2013-05-01 at 17:05 +0200, Rafael J. Wysocki wrote: > On Tuesday, April 30, 2013 05:49:38 PM Toshi Kani wrote: > > On Mon, 2013-04-29 at 14:29 +0200, Rafael J. Wysocki wrote: > > > From: Rafael J. Wysocki > > > > > > Modify the generic ACPI hotplug code to be able to check if devices > > > scheduled for hot-removal may be gracefully removed from the system > > > using the device offline/online mechanism introduced previously. > > > > > > Namely, make acpi_scan_hot_remove() which handles device hot-removal > > > call device_offline() for all physical companions of the ACPI device > > > nodes involved in the operation and check the results. If any of > > > the device_offline() calls fails, the function will not progress to > > > the removal phase (which cannot be aborted), unless its (new) force > > > argument is set (in case of a failing offline it will put the devices > > > offlined by it back online). > > > > > > In support of the 'forced' hot-removal, add a new sysfs attribute > > > 'force_remove' that will reside in every ACPI hotplug profile > > > present under /sys/firmware/acpi/hotplug/. > > > > > > Signed-off-by: Rafael J. Wysocki > > > --- > > > Documentation/ABI/testing/sysfs-firmware-acpi | 9 +- > > > drivers/acpi/internal.h | 2 > > > drivers/acpi/scan.c | 97 ++++++++++++++++++++++++-- > > > drivers/acpi/sysfs.c | 27 +++++++ > > > include/acpi/acpi_bus.h | 3 > > > 5 files changed, 131 insertions(+), 7 deletions(-) > > > > > : > > > Index: linux-pm/drivers/acpi/scan.c > > > =================================================================== > > > --- linux-pm.orig/drivers/acpi/scan.c > > > +++ linux-pm/drivers/acpi/scan.c > > > @@ -120,7 +120,61 @@ acpi_device_modalias_show(struct device > > > } > > > static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL); > > > > > > -static int acpi_scan_hot_remove(struct acpi_device *device) > > > +static acpi_status acpi_bus_offline_companions(acpi_handle handle, u32 lvl, > > > + void *data, void **ret_p) > > > +{ > > > + struct acpi_device *device = NULL; > > > + struct acpi_device_physical_node *pn; > > > + bool force = *((bool *)data); > > > + acpi_status status = AE_OK; > > > + > > > + if (acpi_bus_get_device(handle, &device)) > > > + return AE_OK; > > > + > > > + mutex_lock(&device->physical_node_lock); > > > + > > > + list_for_each_entry(pn, &device->physical_node_list, node) { > > > > I do not think physical_node_list is set for ACPI processor devices, so > > this code is NOP at this point. I think properly initializing > > physical_node_list for CPU and memblk is one of the key items in this > > approach. > > It surely is. :-) > > I've almost done that for CPUs, but that still requires some more work. > Hopefully, it'll be mostly done later this week. Cool! > Memory will take some more time I guess, though. Yes, memory has an ordering issue when using glue.c. https://lkml.org/lkml/2013/3/26/398 Thanks, -Toshi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/