Re: [PATCH] perf/x86/intel/rapl: Rename rapl_cpu_prepare() to rapl_cpu_starting()
On 01/30/2017 11:56 AM, Thomas Gleixner wrote: On Mon, 30 Jan 2017, Yasuaki Ishimatsu wrote: Hi Thomas, Do you have any idea to fix the issue? If you have the idea, please send me the patch. Yes, I have a patch, but need to do some tests and get changelogs written. Will keep you updated. Great!! I wait for your patch. Thanks, Yasuaki Ishimatsu Thanks, tglx
Re: [PATCH] perf/x86/intel/rapl: Rename rapl_cpu_prepare() to rapl_cpu_starting()
On Mon, 30 Jan 2017, Yasuaki Ishimatsu wrote: > Hi Thomas, > > Do you have any idea to fix the issue? > If you have the idea, please send me the patch. Yes, I have a patch, but need to do some tests and get changelogs written. Will keep you updated. Thanks, tglx
Re: [PATCH] perf/x86/intel/rapl: Rename rapl_cpu_prepare() to rapl_cpu_starting()
Hi Thomas, Do you have any idea to fix the issue? If you have the idea, please send me the patch. Thanks, Yasuaki Ishimatsu On 01/24/2017 02:54 PM, Thomas Gleixner wrote: On Tue, 24 Jan 2017, Yasuaki Ishimatsu wrote: rapl_cpu_prepare() must be called after logical package id of CPU is set by topology_update_package_map(). But when onlining hot-added CPU, rapl_cpu_prepare() is called before setting logical package id of the hot-added CPU. So cpu_to_rapl_pmu() in rapl_cpu_prepare() finds a rapl_pmu of wrong logical package id and rapl_cpu_prepare() initializes the wrong rapl_pmu. After that logical package id of the hot-added CPU is set by topology_update_package_map(). But rapl_cpu_prepare() does not initialize pmu of the logical package id of the hot-added CPU. So when calling rapl_cpu_online(), cpu_to_rapl_pmu() returns NULL and the following NULL pointer dereference occurs. BUG: unable to handle kernel NULL pointer dereference at 0008 IP: rapl_cpu_online+0x8d/0xb0 Call Trace: ? rapl_cpu_offline+0xc0/0xc0 cpuhp_invoke_callback+0x8d/0x3f0 cpuhp_up_callbacks+0x37/0xb0 cpuhp_thread_fun+0xc9/0xe0 smpboot_thread_fn+0x110/0x160 kthread+0x101/0x140 ? sort_range+0x30/0x30 ? kthread_park+0x90/0x90 ret_from_fork+0x25/0x30 The patch renames rapl_cpu_prepare() to rapl_cpu_starting() and changes the position of cpuhp_state so that rapl_cpu_starting() is called after topology_update_package_map(). Does not work. You cannot call that callback in the starting context. It does allocations. This needs be fixed in a different way. I'll have a look tomorrow. Thanks, tglx
Re: [PATCH] perf/x86/intel/rapl: Rename rapl_cpu_prepare() to rapl_cpu_starting()
Hi Thomas, Thank you for your review. I'm not familiar with the component. So I need your help to fix the issue. Thanks, Yasuaki Ishimatsu On 01/24/2017 02:54 PM, Thomas Gleixner wrote: On Tue, 24 Jan 2017, Yasuaki Ishimatsu wrote: rapl_cpu_prepare() must be called after logical package id of CPU is set by topology_update_package_map(). But when onlining hot-added CPU, rapl_cpu_prepare() is called before setting logical package id of the hot-added CPU. So cpu_to_rapl_pmu() in rapl_cpu_prepare() finds a rapl_pmu of wrong logical package id and rapl_cpu_prepare() initializes the wrong rapl_pmu. After that logical package id of the hot-added CPU is set by topology_update_package_map(). But rapl_cpu_prepare() does not initialize pmu of the logical package id of the hot-added CPU. So when calling rapl_cpu_online(), cpu_to_rapl_pmu() returns NULL and the following NULL pointer dereference occurs. BUG: unable to handle kernel NULL pointer dereference at 0008 IP: rapl_cpu_online+0x8d/0xb0 Call Trace: ? rapl_cpu_offline+0xc0/0xc0 cpuhp_invoke_callback+0x8d/0x3f0 cpuhp_up_callbacks+0x37/0xb0 cpuhp_thread_fun+0xc9/0xe0 smpboot_thread_fn+0x110/0x160 kthread+0x101/0x140 ? sort_range+0x30/0x30 ? kthread_park+0x90/0x90 ret_from_fork+0x25/0x30 The patch renames rapl_cpu_prepare() to rapl_cpu_starting() and changes the position of cpuhp_state so that rapl_cpu_starting() is called after topology_update_package_map(). Does not work. You cannot call that callback in the starting context. It does allocations. This needs be fixed in a different way. I'll have a look tomorrow. Thanks, tglx
Re: [PATCH] perf/x86/intel/rapl: Rename rapl_cpu_prepare() to rapl_cpu_starting()
On Tue, 24 Jan 2017, Yasuaki Ishimatsu wrote: > rapl_cpu_prepare() must be called after logical package id of CPU > is set by topology_update_package_map(). > > But when onlining hot-added CPU, rapl_cpu_prepare() is called before > setting logical package id of the hot-added CPU. So cpu_to_rapl_pmu() > in rapl_cpu_prepare() finds a rapl_pmu of wrong logical package id and > rapl_cpu_prepare() initializes the wrong rapl_pmu. > > After that logical package id of the hot-added CPU is set by > topology_update_package_map(). But rapl_cpu_prepare() does > not initialize pmu of the logical package id of the hot-added CPU. > So when calling rapl_cpu_online(), cpu_to_rapl_pmu() returns NULL and > the following NULL pointer dereference occurs. > > BUG: unable to handle kernel NULL pointer dereference at 0008 > IP: rapl_cpu_online+0x8d/0xb0 > > Call Trace: >? rapl_cpu_offline+0xc0/0xc0 >cpuhp_invoke_callback+0x8d/0x3f0 >cpuhp_up_callbacks+0x37/0xb0 >cpuhp_thread_fun+0xc9/0xe0 >smpboot_thread_fn+0x110/0x160 >kthread+0x101/0x140 >? sort_range+0x30/0x30 >? kthread_park+0x90/0x90 >ret_from_fork+0x25/0x30 > > The patch renames rapl_cpu_prepare() to rapl_cpu_starting() and changes > the position of cpuhp_state so that rapl_cpu_starting() is called > after topology_update_package_map(). Does not work. You cannot call that callback in the starting context. It does allocations. This needs be fixed in a different way. I'll have a look tomorrow. Thanks, tglx
[PATCH] perf/x86/intel/rapl: Rename rapl_cpu_prepare() to rapl_cpu_starting()
rapl_cpu_prepare() must be called after logical package id of CPU
is set by topology_update_package_map().
But when onlining hot-added CPU, rapl_cpu_prepare() is called before
setting logical package id of the hot-added CPU. So cpu_to_rapl_pmu()
in rapl_cpu_prepare() finds a rapl_pmu of wrong logical package id and
rapl_cpu_prepare() initializes the wrong rapl_pmu.
After that logical package id of the hot-added CPU is set by
topology_update_package_map(). But rapl_cpu_prepare() does
not initialize pmu of the logical package id of the hot-added CPU.
So when calling rapl_cpu_online(), cpu_to_rapl_pmu() returns NULL and
the following NULL pointer dereference occurs.
BUG: unable to handle kernel NULL pointer dereference at 0008
IP: rapl_cpu_online+0x8d/0xb0
Call Trace:
? rapl_cpu_offline+0xc0/0xc0
cpuhp_invoke_callback+0x8d/0x3f0
cpuhp_up_callbacks+0x37/0xb0
cpuhp_thread_fun+0xc9/0xe0
smpboot_thread_fn+0x110/0x160
kthread+0x101/0x140
? sort_range+0x30/0x30
? kthread_park+0x90/0x90
ret_from_fork+0x25/0x30
The patch renames rapl_cpu_prepare() to rapl_cpu_starting() and changes
the position of cpuhp_state so that rapl_cpu_starting() is called
after topology_update_package_map().
Fixes: 9de8d686955b ("perf/x86/intel/rapl: Convert it to a per package
facility")
Signed-off-by: Yasuaki Ishimatsu
CC: Thomas Gleixner
---
arch/x86/events/intel/rapl.c | 11 ++-
include/linux/cpuhotplug.h | 2 +-
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/arch/x86/events/intel/rapl.c b/arch/x86/events/intel/rapl.c
index 17c3564..f762cd6 100644
--- a/arch/x86/events/intel/rapl.c
+++ b/arch/x86/events/intel/rapl.c
@@ -598,7 +598,7 @@ static int rapl_cpu_online(unsigned int cpu)
return 0;
}
-static int rapl_cpu_prepare(unsigned int cpu)
+static int rapl_cpu_starting(unsigned int cpu)
{
struct rapl_pmu *pmu = cpu_to_rapl_pmu(cpu);
@@ -804,8 +804,9 @@ static int __init rapl_pmu_init(void)
* Install callbacks. Core will call them for each online cpu.
*/
- ret = cpuhp_setup_state(CPUHP_PERF_X86_RAPL_PREP,
"perf/x86/rapl:prepare",
- rapl_cpu_prepare, NULL);
+ ret = cpuhp_setup_state(CPUHP_AP_PERF_X86_RAPL_STARTING,
+ "perf/x86/rapl:starting",
+ rapl_cpu_starting, NULL);
if (ret)
goto out;
@@ -825,7 +826,7 @@ static int __init rapl_pmu_init(void)
out2:
cpuhp_remove_state(CPUHP_AP_PERF_X86_RAPL_ONLINE);
out1:
- cpuhp_remove_state(CPUHP_PERF_X86_RAPL_PREP);
+ cpuhp_remove_state(CPUHP_AP_PERF_X86_RAPL_STARTING);
out:
pr_warn("Initialization failed (%d), disabled\n", ret);
cleanup_rapl_pmus();
@@ -836,7 +837,7 @@ static int __init rapl_pmu_init(void)
static void __exit intel_rapl_exit(void)
{
cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_RAPL_ONLINE);
- cpuhp_remove_state_nocalls(CPUHP_PERF_X86_RAPL_PREP);
+ cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_RAPL_STARTING);
perf_pmu_unregister(&rapl_pmus->pmu);
cleanup_rapl_pmus();
}
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index d936a00..63da322 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -10,7 +10,6 @@ enum cpuhp_state {
CPUHP_PERF_X86_PREPARE,
CPUHP_PERF_X86_UNCORE_PREP,
CPUHP_PERF_X86_AMD_UNCORE_PREP,
- CPUHP_PERF_X86_RAPL_PREP,
CPUHP_PERF_BFIN,
CPUHP_PERF_POWER,
CPUHP_PERF_SUPERH,
@@ -90,6 +89,7 @@ enum cpuhp_state {
CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
CPUHP_AP_PERF_X86_STARTING,
CPUHP_AP_PERF_X86_AMD_IBS_STARTING,
+ CPUHP_AP_PERF_X86_RAPL_STARTING,
CPUHP_AP_PERF_X86_CQM_STARTING,
CPUHP_AP_PERF_X86_CSTATE_STARTING,
CPUHP_AP_PERF_XTENSA_STARTING,
--
1.8.3.1
