Re: [PATCH 1/2][Untested] ACPI / hotplug: Add demand_offline hotplugprofile flag
From: Yasuaki Ishimatsu
Date: Wed Dec 25 2013 - 23:11:29 EST
(2013/12/26 12:10), Yasuaki Ishimatsu wrote:
(2013/12/23 23:00), Rafael J. Wysocki wrote:
From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Add a new ACPI hotplug profile flag, demand_offline, such that if
set for the given ACPI device object's scan handler, it will cause
acpi_scan_hot_remove() to check if that device object's physical
companions are offline upfront and fail the hot removal if that
is not the case.
That flag will be useful to overcome a problem with containers on
some system where they can only be hot-removed after some cleanup
operations carried out by user space, which needs to be notified
of the container hot-removal before the kernel attempts to offline
devices in the container. In those cases the current implementation
of acpi_scan_hot_remove() is not sufficient, because it first tries
to offline the devices in the container and only if that is
suffcessful it tries to offline the container itself. As a result,
the container hot-removal notification is not delivered to user space
at the right time.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/acpi/scan.c | 41 +++++++++++++++++++++++++++++++++++++----
include/acpi/acpi_bus.h | 3 ++-
2 files changed, 39 insertions(+), 5 deletions(-)
Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -126,6 +126,24 @@ acpi_device_modalias_show(struct device
}
static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
+static bool acpi_scan_is_offline(struct acpi_device *adev)
+{
+ struct acpi_device_physical_node *pn;
+ bool offline = true;
+
+ mutex_lock(&adev->physical_node_lock);
+
+ list_for_each_entry(pn, &adev->physical_node_list, node)
+ if (!pn->dev->offline) {
Please check pn->dev->bus and pn->dev->bus->offline too as follow:
if (pn->dev->bus && pn->dev->bus->offline &&
!pn->dev->offline) {
Adding above check, I could remove container device by using eject sysfs.
But following messages were shown:
[ 1017.543000] ------------[ cut here ]------------
[ 1017.543000] WARNING: CPU: 0 PID: 6 at drivers/base/core.c:251 device_release+0x92/0xa0()
[ 1017.543000] Device 'ACPI0004:01' does not have a release() function, it is broken and must be fixed.
[ 1017.653000] Modules linked in: xt_CHECKSUM nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT ipmi_devintf ipt_REJECT cfg80211 xt_conntrack rfkill ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6
ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iptable_filter sg ip_tables vfat fat x86_pkg_temp_thermal coretemp iTCO_wdt iTCO_vendor_support kvm_intel
kvm crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd dm_mirror dm_region_hash dm_log dm_mod microcode lpc_ich igb sb_edac e1000e pcspkr i2c_i801
[ 1017.653000] edac_core mfd_core dca ptp pps_core shpchp ipmi_si ipmi_msghandler tpm_infineon nfsd auth_rpcgss nfs_acl lockd sunrpc xfs libcrc32c sd_mod mgag200 syscopyarea sysfillrect sysimgblt lpfc i2c_algo_bit drm_kms_helper ttm drm crc_t10dif crct10dif_common scsi_transport_fc megaraid_sas
i2c_core scsi_tgt
[ 1017.653000] CPU: 0 PID: 6 Comm: kworker/u512:0 Tainted: G W 3.13.0-rc5+ #5
[ 1017.653000] Hardware name:
[ 1017.653000] Workqueue: kacpi_hotplug acpi_hotplug_work_fn
[ 1017.653000] 0000000000000009 ffff880873a6dc68 ffffffff815d85ca ffff880873a6dcb0
[ 1017.653000] ffff880873a6dca0 ffffffff8106594d ffff8a07d221c010 ffff8a07d221c000
[ 1017.653000] ffff8808715472c0 ffff880871e91018 0000000000000103 ffff880873a6dd00
[ 1017.653000] Call Trace:
[ 1017.653000] [<ffffffff815d85ca>] dump_stack+0x45/0x56
[ 1017.653000] [<ffffffff8106594d>] warn_slowpath_common+0x7d/0xa0
[ 1017.653000] [<ffffffff810659bc>] warn_slowpath_fmt+0x4c/0x50
[ 1017.653000] [<ffffffff813ad892>] device_release+0x92/0xa0
[ 1017.653000] [<ffffffff812b7197>] kobject_cleanup+0x77/0x1b0
[ 1017.653000] [<ffffffff812b7045>] kobject_put+0x35/0x70
[ 1017.653000] [<ffffffff813ae38c>] device_unregister+0x2c/0x60
[ 1017.653000] [<ffffffff8134c87c>] container_device_detach+0x28/0x2a
[ 1017.653000] [<ffffffff81323096>] acpi_bus_trim+0x56/0x89
[ 1017.653000] [<ffffffff813246ae>] acpi_device_hotplug+0x168/0x383
[ 1017.653000] [<ffffffff8131efba>] acpi_hotplug_work_fn+0x1c/0x27
[ 1017.653000] [<ffffffff81080f1b>] process_one_work+0x17b/0x460
[ 1017.653000] [<ffffffff81081ccb>] worker_thread+0x11b/0x400
[ 1017.653000] [<ffffffff81081bb0>] ? rescuer_thread+0x3e0/0x3e0
[ 1017.653000] [<ffffffff81088a12>] kthread+0xd2/0xf0
[ 1017.653000] [<ffffffff81088940>] ? kthread_create_on_node+0x180/0x180
[ 1017.653000] [<ffffffff815e82fc>] ret_from_fork+0x7c/0xb0
[ 1017.653000] [<ffffffff81088940>] ? kthread_create_on_node+0x180/0x180
[ 1017.653000] ---[ end trace 41394323eb4b690a ]---
Thanks,
Yasuaki Ishimatsu
My container has CPU and Memory and PCI root bridge. PCI root bridge
does not has offline function (pn->dev->bus->offline). So I cannot offline
the device and pn->dev->offline of the device is always 0. Therefore,
following operation always returns -EBUSY even if I offline CPUs and
all memory sections on a container device.
echo 0 > /sys/bus/container/devices/ACPI0004:01/online
Thanks,
Yasuaki Ishimatsu
+ kobject_uevent(&pn->dev->kobj, KOBJ_CHANGE);
+ offline = false;
+ break;
+ }
+
+ mutex_unlock(&adev->physical_node_lock);
+ return offline;
+}
+
static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
void **ret_p)
{
@@ -196,12 +214,11 @@ static acpi_status acpi_bus_online(acpi_
return AE_OK;
}
-static int acpi_scan_hot_remove(struct acpi_device *device)
+static int acpi_scan_try_to_offline(struct acpi_device *device)
{
acpi_handle handle = device->handle;
- struct device *errdev;
+ struct device *errdev = NULL;
acpi_status status;
- unsigned long long sta;
/*
* Carry out two passes here and ignore errors in the first pass,
@@ -212,7 +229,6 @@ static int acpi_scan_hot_remove(struct a
*
* If the first pass is successful, the second one isn't needed, though.
*/
- errdev = NULL;
status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
NULL, acpi_bus_offline, (void *)false,
(void **)&errdev);
@@ -241,6 +257,23 @@ static int acpi_scan_hot_remove(struct a
return -EBUSY;
}
}
+ return 0;
+}
+
+static int acpi_scan_hot_remove(struct acpi_device *device)
+{
+ acpi_handle handle = device->handle;
+ unsigned long long sta;
+ acpi_status status;
+
+ if (device->handler->hotplug.demand_offline && !acpi_force_hot_remove) {
+ if (!acpi_scan_is_offline(device))
+ return -EBUSY;
+ } else {
+ int error = acpi_scan_try_to_offline(device);
+ if (error)
+ return error;
+ }
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Hot-removing device %s...\n", dev_name(&device->dev)));
Index: linux-pm/include/acpi/acpi_bus.h
===================================================================
--- linux-pm.orig/include/acpi/acpi_bus.h
+++ linux-pm/include/acpi/acpi_bus.h
@@ -91,8 +91,9 @@ struct acpi_device;
struct acpi_hotplug_profile {
struct kobject kobj;
- bool enabled:1;
int (*scan_dependent)(struct acpi_device *adev);
+ bool enabled:1;
+ bool demand_offline:1;
};
static inline struct acpi_hotplug_profile *to_acpi_hotplug_profile(
--
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