A system that supports resource monitoring may have multiple resources
while not all of these resources are capable of monitoring. Monitoring
related state is initialized only for resources that are capable of
monitoring and correspondingly this state should subsequently only be
removed from these resources that are capable of monitoring.
domain_add_cpu() calls domain_setup_mon_state() only when r->mon_capable
is true where it will initialize d->mbm_over. However,
domain_remove_cpu() calls cancel_delayed_work(&d->mbm_over) without
checking r->mon_capable resulting in an attempt to cancel d->mbm_over on
all resources, even those that never initialized d->mbm_over because
they are not capable of monitoring. Hence, it triggers a debugobjects
warning when offlining CPUs because those timer debugobjects are never
initialized.
ODEBUG: assert_init not available (active state 0) object type:
timer_list hint: 0x0
WARNING: CPU: 143 PID: 789 at lib/debugobjects.c:484
debug_print_object+0xfe/0x140
Hardware name: HP Synergy 680 Gen9/Synergy 680 Gen9 Compute Module, BIOS
I40 05/23/2018
RIP: 0010:debug_print_object+0xfe/0x140
Call Trace:
debug_object_assert_init+0x1f5/0x240
del_timer+0x6f/0xf0
try_to_grab_pending+0x42/0x3c0
cancel_delayed_work+0x7d/0x150
resctrl_offline_cpu+0x3c0/0x520
cpuhp_invoke_callback+0x197/0x1120
cpuhp_thread_fun+0x252/0x2f0
smpboot_thread_fn+0x255/0x440
kthread+0x1e6/0x210
ret_from_fork+0x3a/0x50
Fixes: e33026831bdb ("x86/intel_rdt/mbm: Handle counter overflow")
Signed-off-by: Qian Cai <[email protected]>
---
v2: update the commit log thanks to Reinette.
arch/x86/kernel/cpu/resctrl/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 03eb90d00af0..89049b343c7a 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -618,7 +618,7 @@ static void domain_remove_cpu(int cpu, struct rdt_resource *r)
if (static_branch_unlikely(&rdt_mon_enable_key))
rmdir_mondata_subdir_allrdtgrp(r, d->id);
list_del(&d->list);
- if (is_mbm_enabled())
+ if (r->mon_capable && is_mbm_enabled())
cancel_delayed_work(&d->mbm_over);
if (is_llc_occupancy_enabled() && has_busy_rmid(r, d)) {
/*
--
2.21.0 (Apple Git-122.2)
Hi Qian,
On 12/10/2019 7:30 PM, Qian Cai wrote:
> A system that supports resource monitoring may have multiple resources
> while not all of these resources are capable of monitoring. Monitoring
> related state is initialized only for resources that are capable of
> monitoring and correspondingly this state should subsequently only be
> removed from these resources that are capable of monitoring.
>
> domain_add_cpu() calls domain_setup_mon_state() only when r->mon_capable
> is true where it will initialize d->mbm_over. However,
> domain_remove_cpu() calls cancel_delayed_work(&d->mbm_over) without
> checking r->mon_capable resulting in an attempt to cancel d->mbm_over on
> all resources, even those that never initialized d->mbm_over because
> they are not capable of monitoring. Hence, it triggers a debugobjects
> warning when offlining CPUs because those timer debugobjects are never
> initialized.
>
> ODEBUG: assert_init not available (active state 0) object type:
> timer_list hint: 0x0
> WARNING: CPU: 143 PID: 789 at lib/debugobjects.c:484
> debug_print_object+0xfe/0x140
> Hardware name: HP Synergy 680 Gen9/Synergy 680 Gen9 Compute Module, BIOS
> I40 05/23/2018
> RIP: 0010:debug_print_object+0xfe/0x140
> Call Trace:
> debug_object_assert_init+0x1f5/0x240
> del_timer+0x6f/0xf0
> try_to_grab_pending+0x42/0x3c0
> cancel_delayed_work+0x7d/0x150
> resctrl_offline_cpu+0x3c0/0x520
> cpuhp_invoke_callback+0x197/0x1120
> cpuhp_thread_fun+0x252/0x2f0
> smpboot_thread_fn+0x255/0x440
> kthread+0x1e6/0x210
> ret_from_fork+0x3a/0x50
>
> Fixes: e33026831bdb ("x86/intel_rdt/mbm: Handle counter overflow")
> Signed-off-by: Qian Cai <[email protected]>
> ---
Thank you very much.
Acked-by: Reinette Chatre <[email protected]>
Reinette
The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: e278af89f1ba0a9ef20947db6afc2c9afa37e85b
Gitweb: https://git.kernel.org/tip/e278af89f1ba0a9ef20947db6afc2c9afa37e85b
Author: Qian Cai <[email protected]>
AuthorDate: Tue, 10 Dec 2019 22:30:42 -05:00
Committer: Borislav Petkov <[email protected]>
CommitterDate: Mon, 30 Dec 2019 19:25:59 +01:00
x86/resctrl: Fix an imbalance in domain_remove_cpu()
A system that supports resource monitoring may have multiple resources
while not all of these resources are capable of monitoring. Monitoring
related state is initialized only for resources that are capable of
monitoring and correspondingly this state should subsequently only be
removed from these resources that are capable of monitoring.
domain_add_cpu() calls domain_setup_mon_state() only when r->mon_capable
is true where it will initialize d->mbm_over. However,
domain_remove_cpu() calls cancel_delayed_work(&d->mbm_over) without
checking r->mon_capable resulting in an attempt to cancel d->mbm_over on
all resources, even those that never initialized d->mbm_over because
they are not capable of monitoring. Hence, it triggers a debugobjects
warning when offlining CPUs because those timer debugobjects are never
initialized:
ODEBUG: assert_init not available (active state 0) object type:
timer_list hint: 0x0
WARNING: CPU: 143 PID: 789 at lib/debugobjects.c:484
debug_print_object
Hardware name: HP Synergy 680 Gen9/Synergy 680 Gen9 Compute Module, BIOS I40 05/23/2018
RIP: 0010:debug_print_object
Call Trace:
debug_object_assert_init
del_timer
try_to_grab_pending
cancel_delayed_work
resctrl_offline_cpu
cpuhp_invoke_callback
cpuhp_thread_fun
smpboot_thread_fn
kthread
ret_from_fork
Fixes: e33026831bdb ("x86/intel_rdt/mbm: Handle counter overflow")
Signed-off-by: Qian Cai <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Acked-by: Reinette Chatre <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: Tony Luck <[email protected]>
Cc: Vikas Shivappa <[email protected]>
Cc: x86-ml <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
---
arch/x86/kernel/cpu/resctrl/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 03eb90d..89049b3 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -618,7 +618,7 @@ static void domain_remove_cpu(int cpu, struct rdt_resource *r)
if (static_branch_unlikely(&rdt_mon_enable_key))
rmdir_mondata_subdir_allrdtgrp(r, d->id);
list_del(&d->list);
- if (is_mbm_enabled())
+ if (r->mon_capable && is_mbm_enabled())
cancel_delayed_work(&d->mbm_over);
if (is_llc_occupancy_enabled() && has_busy_rmid(r, d)) {
/*