It was found that the following warning message could be printed out when
booting the kernel on PowerPC systems that support LPAR:
[ 0.129584] WARNING: CPU: 0 PID: 1 at mm/memblock.c:1451 memblock_alloc_internal+0x5c/0x104
[ 0.129593] Modules linked in:
[ 0.129598] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.14.0-11.el9.ppc64le+debug #1
[ 0.129605] NIP: c000000002040134 LR: c00000000204011c CTR: c0000000020241a8
[ 0.129610] REGS: c000000005637760 TRAP: 0700 Not tainted (5.14.0-11.el9.ppc64le+debug)
[ 0.129616] MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 48000222 XER: 00000002
[ 0.129635] CFAR: c0000000004d1cf4 IRQMASK: 0
[ 0.129635] GPR00: c00000000204011c c000000005637a00 c000000002c94d00 0000000000000001
[ 0.129635] GPR04: 0000000000000080 0000000000000000 0000000000000000 ffffffffffffffff
[ 0.129635] GPR08: 0000000000000000 0000000000000003 c00000000205ac64 0000000000080000
[ 0.129635] GPR12: 0000000000000000 c0000000049d0000 c000000000013078 0000000000000000
[ 0.129635] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 0.129635] GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 0.129635] GPR24: c000000002003808 c00000000146f7b8 0000000000000000 0000000000000100
[ 0.129635] GPR28: c000000002d7cf80 0000000000000000 0000000000000008 0000000000000000
[ 0.129710] NIP [c000000002040134] memblock_alloc_internal+0x5c/0x104
[ 0.129717] LR [c00000000204011c] memblock_alloc_internal+0x44/0x104
[ 0.129723] Call Trace:
[ 0.129726] [c000000005637a00] [c000000005637a40] 0xc000000005637a40 (unreliable)
[ 0.129735] [c000000005637a60] [c0000000020404d8] memblock_alloc_try_nid+0x94/0xcc
[ 0.129743] [c000000005637af0] [c00000000205ac64] alloc_bootmem_cpumask_var+0x4c/0x9c
[ 0.129751] [c000000005637b60] [c0000000020242e0] __machine_initcall_pseries_pseries_cpu_hotplug_init+0x138/0x1d8
[ 0.129760] [c000000005637bf0] [c000000000012404] do_one_initcall+0xa4/0x4f0
[ 0.129768] [c000000005637cd0] [c000000002005358] do_initcalls+0x140/0x18c
[ 0.129776] [c000000005637d80] [c0000000020055b8] kernel_init_freeable+0x178/0x1d0
[ 0.129783] [c000000005637db0] [c0000000000130a0] kernel_init+0x30/0x190
[ 0.129790] [c000000005637e10] [c00000000000cef4] ret_from_kernel_thread+0x5c/0x64
The warning is printed in memblock_alloc_internal() because the slab
has been initialized when the initcalls are being processed. To
avoid the warning, change alloc_bootmem_cpumask_var() call in
pseries_cpu_hotplug_init() to alloc_cpumask_var() instead. Also
change cpumask_or() to cpumask_copy() or we will have to use
zalloc_cpumask_var().
Fixes: bd1dd4c5f528 ("powerpc/pseries: Prevent free CPU ids being reused on another node")
Signed-off-by: Waiman Long <[email protected]>
---
arch/powerpc/platforms/pseries/hotplug-cpu.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 5ab44600c8d3..e8e08d916b16 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -864,12 +864,12 @@ static int __init pseries_cpu_hotplug_init(void)
/* Processors can be added/removed only on LPAR */
if (firmware_has_feature(FW_FEATURE_LPAR)) {
for_each_node(node) {
- alloc_bootmem_cpumask_var(&node_recorded_ids_map[node]);
+ alloc_cpumask_var(&node_recorded_ids_map[node],
+ GFP_KERNEL|GFP_NOWAIT);
/* Record ids of CPU added at boot time */
- cpumask_or(node_recorded_ids_map[node],
- node_recorded_ids_map[node],
- cpumask_of_node(node));
+ cpumask_copy(node_recorded_ids_map[node],
+ cpumask_of_node(node));
}
of_reconfig_notifier_register(&pseries_smp_nb);
--
2.27.0
Waiman Long <[email protected]> writes:
> It was found that the following warning message could be printed out when
> booting the kernel on PowerPC systems that support LPAR:
>
> [ 0.129584] WARNING: CPU: 0 PID: 1 at mm/memblock.c:1451 memblock_alloc_internal+0x5c/0x104
> [ 0.129593] Modules linked in:
> [ 0.129598] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.14.0-11.el9.ppc64le+debug #1
> [ 0.129605] NIP: c000000002040134 LR: c00000000204011c CTR: c0000000020241a8
> [ 0.129610] REGS: c000000005637760 TRAP: 0700 Not tainted (5.14.0-11.el9.ppc64le+debug)
> [ 0.129616] MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 48000222 XER: 00000002
> [ 0.129635] CFAR: c0000000004d1cf4 IRQMASK: 0
> [ 0.129635] GPR00: c00000000204011c c000000005637a00 c000000002c94d00 0000000000000001
> [ 0.129635] GPR04: 0000000000000080 0000000000000000 0000000000000000 ffffffffffffffff
> [ 0.129635] GPR08: 0000000000000000 0000000000000003 c00000000205ac64 0000000000080000
> [ 0.129635] GPR12: 0000000000000000 c0000000049d0000 c000000000013078 0000000000000000
> [ 0.129635] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> [ 0.129635] GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> [ 0.129635] GPR24: c000000002003808 c00000000146f7b8 0000000000000000 0000000000000100
> [ 0.129635] GPR28: c000000002d7cf80 0000000000000000 0000000000000008 0000000000000000
> [ 0.129710] NIP [c000000002040134] memblock_alloc_internal+0x5c/0x104
> [ 0.129717] LR [c00000000204011c] memblock_alloc_internal+0x44/0x104
> [ 0.129723] Call Trace:
> [ 0.129726] [c000000005637a00] [c000000005637a40] 0xc000000005637a40 (unreliable)
> [ 0.129735] [c000000005637a60] [c0000000020404d8] memblock_alloc_try_nid+0x94/0xcc
> [ 0.129743] [c000000005637af0] [c00000000205ac64] alloc_bootmem_cpumask_var+0x4c/0x9c
> [ 0.129751] [c000000005637b60] [c0000000020242e0] __machine_initcall_pseries_pseries_cpu_hotplug_init+0x138/0x1d8
> [ 0.129760] [c000000005637bf0] [c000000000012404] do_one_initcall+0xa4/0x4f0
> [ 0.129768] [c000000005637cd0] [c000000002005358] do_initcalls+0x140/0x18c
> [ 0.129776] [c000000005637d80] [c0000000020055b8] kernel_init_freeable+0x178/0x1d0
> [ 0.129783] [c000000005637db0] [c0000000000130a0] kernel_init+0x30/0x190
> [ 0.129790] [c000000005637e10] [c00000000000cef4] ret_from_kernel_thread+0x5c/0x64
>
> The warning is printed in memblock_alloc_internal() because the slab
> has been initialized when the initcalls are being processed. To
> avoid the warning, change alloc_bootmem_cpumask_var() call in
> pseries_cpu_hotplug_init() to alloc_cpumask_var() instead. Also
> change cpumask_or() to cpumask_copy() or we will have to use
> zalloc_cpumask_var().
>
> Fixes: bd1dd4c5f528 ("powerpc/pseries: Prevent free CPU ids being reused on another node")
> Signed-off-by: Waiman Long <[email protected]>
> ---
> arch/powerpc/platforms/pseries/hotplug-cpu.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
This looks similar to the patch Nick sent recently:
https://lore.kernel.org/linuxppc-dev/[email protected]/
cheers
On 11/8/21 20:46, Nicholas Piggin wrote:
> Excerpts from Michael Ellerman's message of November 9, 2021 11:04 am:
>> Waiman Long <[email protected]> writes:
>>> It was found that the following warning message could be printed out when
>>> booting the kernel on PowerPC systems that support LPAR:
>>>
>>> [ 0.129584] WARNING: CPU: 0 PID: 1 at mm/memblock.c:1451 memblock_alloc_internal+0x5c/0x104
>>> [ 0.129593] Modules linked in:
>>> [ 0.129598] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.14.0-11.el9.ppc64le+debug #1
>>> [ 0.129605] NIP: c000000002040134 LR: c00000000204011c CTR: c0000000020241a8
>>> [ 0.129610] REGS: c000000005637760 TRAP: 0700 Not tainted (5.14.0-11.el9.ppc64le+debug)
>>> [ 0.129616] MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 48000222 XER: 00000002
>>> [ 0.129635] CFAR: c0000000004d1cf4 IRQMASK: 0
>>> [ 0.129635] GPR00: c00000000204011c c000000005637a00 c000000002c94d00 0000000000000001
>>> [ 0.129635] GPR04: 0000000000000080 0000000000000000 0000000000000000 ffffffffffffffff
>>> [ 0.129635] GPR08: 0000000000000000 0000000000000003 c00000000205ac64 0000000000080000
>>> [ 0.129635] GPR12: 0000000000000000 c0000000049d0000 c000000000013078 0000000000000000
>>> [ 0.129635] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
>>> [ 0.129635] GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
>>> [ 0.129635] GPR24: c000000002003808 c00000000146f7b8 0000000000000000 0000000000000100
>>> [ 0.129635] GPR28: c000000002d7cf80 0000000000000000 0000000000000008 0000000000000000
>>> [ 0.129710] NIP [c000000002040134] memblock_alloc_internal+0x5c/0x104
>>> [ 0.129717] LR [c00000000204011c] memblock_alloc_internal+0x44/0x104
>>> [ 0.129723] Call Trace:
>>> [ 0.129726] [c000000005637a00] [c000000005637a40] 0xc000000005637a40 (unreliable)
>>> [ 0.129735] [c000000005637a60] [c0000000020404d8] memblock_alloc_try_nid+0x94/0xcc
>>> [ 0.129743] [c000000005637af0] [c00000000205ac64] alloc_bootmem_cpumask_var+0x4c/0x9c
>>> [ 0.129751] [c000000005637b60] [c0000000020242e0] __machine_initcall_pseries_pseries_cpu_hotplug_init+0x138/0x1d8
>>> [ 0.129760] [c000000005637bf0] [c000000000012404] do_one_initcall+0xa4/0x4f0
>>> [ 0.129768] [c000000005637cd0] [c000000002005358] do_initcalls+0x140/0x18c
>>> [ 0.129776] [c000000005637d80] [c0000000020055b8] kernel_init_freeable+0x178/0x1d0
>>> [ 0.129783] [c000000005637db0] [c0000000000130a0] kernel_init+0x30/0x190
>>> [ 0.129790] [c000000005637e10] [c00000000000cef4] ret_from_kernel_thread+0x5c/0x64
>>>
>>> The warning is printed in memblock_alloc_internal() because the slab
>>> has been initialized when the initcalls are being processed. To
>>> avoid the warning, change alloc_bootmem_cpumask_var() call in
>>> pseries_cpu_hotplug_init() to alloc_cpumask_var() instead. Also
>>> change cpumask_or() to cpumask_copy() or we will have to use
>>> zalloc_cpumask_var().
>>>
>>> Fixes: bd1dd4c5f528 ("powerpc/pseries: Prevent free CPU ids being reused on another node")
>>> Signed-off-by: Waiman Long <[email protected]>
>>> ---
>>> arch/powerpc/platforms/pseries/hotplug-cpu.c | 8 ++++----
>>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> This looks similar to the patch Nick sent recently:
>>
>> https://lore.kernel.org/linuxppc-dev/[email protected]/
> Ah, you get CONFIG_CPUMASK_OFFSTACK=y if CONFIG_DEBUG_PER_CPU_MAPS=y.
> I was wondering how Waiman found it.
>
> Differences between the two patches are error checking - no big deal but
> we should just do it. And GFP_NOWAIT - is this required here?
As I have replied in another thread, I added it because it was used in
memblock_alloc_internal().
Cheers,
Longman
Waiman Long <[email protected]> writes:
> It was found that the following warning message could be printed out when
> booting the kernel on PowerPC systems that support LPAR:
>
> [ 0.129584] WARNING: CPU: 0 PID: 1 at mm/memblock.c:1451 memblock_alloc_internal+0x5c/0x104
> [ 0.129593] Modules linked in:
> [ 0.129598] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.14.0-11.el9.ppc64le+debug #1
> [ 0.129605] NIP: c000000002040134 LR: c00000000204011c CTR: c0000000020241a8
> [ 0.129610] REGS: c000000005637760 TRAP: 0700 Not tainted (5.14.0-11.el9.ppc64le+debug)
> [ 0.129616] MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 48000222 XER: 00000002
> [ 0.129635] CFAR: c0000000004d1cf4 IRQMASK: 0
> [ 0.129635] GPR00: c00000000204011c c000000005637a00 c000000002c94d00 0000000000000001
> [ 0.129635] GPR04: 0000000000000080 0000000000000000 0000000000000000 ffffffffffffffff
> [ 0.129635] GPR08: 0000000000000000 0000000000000003 c00000000205ac64 0000000000080000
> [ 0.129635] GPR12: 0000000000000000 c0000000049d0000 c000000000013078 0000000000000000
> [ 0.129635] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> [ 0.129635] GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> [ 0.129635] GPR24: c000000002003808 c00000000146f7b8 0000000000000000 0000000000000100
> [ 0.129635] GPR28: c000000002d7cf80 0000000000000000 0000000000000008 0000000000000000
> [ 0.129710] NIP [c000000002040134] memblock_alloc_internal+0x5c/0x104
> [ 0.129717] LR [c00000000204011c] memblock_alloc_internal+0x44/0x104
> [ 0.129723] Call Trace:
> [ 0.129726] [c000000005637a00] [c000000005637a40] 0xc000000005637a40 (unreliable)
> [ 0.129735] [c000000005637a60] [c0000000020404d8] memblock_alloc_try_nid+0x94/0xcc
> [ 0.129743] [c000000005637af0] [c00000000205ac64] alloc_bootmem_cpumask_var+0x4c/0x9c
> [ 0.129751] [c000000005637b60] [c0000000020242e0] __machine_initcall_pseries_pseries_cpu_hotplug_init+0x138/0x1d8
> [ 0.129760] [c000000005637bf0] [c000000000012404] do_one_initcall+0xa4/0x4f0
> [ 0.129768] [c000000005637cd0] [c000000002005358] do_initcalls+0x140/0x18c
> [ 0.129776] [c000000005637d80] [c0000000020055b8] kernel_init_freeable+0x178/0x1d0
> [ 0.129783] [c000000005637db0] [c0000000000130a0] kernel_init+0x30/0x190
> [ 0.129790] [c000000005637e10] [c00000000000cef4] ret_from_kernel_thread+0x5c/0x64
>
> The warning is printed in memblock_alloc_internal() because the slab
> has been initialized when the initcalls are being processed.
Looks like CONFIG_CPUMASK_OFFSTACK=y is necessary for the warning to
trigger... guess that explains how it's escaped notice.
> To
> avoid the warning, change alloc_bootmem_cpumask_var() call in
> pseries_cpu_hotplug_init() to alloc_cpumask_var() instead. Also
> change cpumask_or() to cpumask_copy() or we will have to use
> zalloc_cpumask_var().
Makes sense.
> Fixes: bd1dd4c5f528 ("powerpc/pseries: Prevent free CPU ids being reused on another node")
> Signed-off-by: Waiman Long <[email protected]>
> ---
> arch/powerpc/platforms/pseries/hotplug-cpu.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
> index 5ab44600c8d3..e8e08d916b16 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
> @@ -864,12 +864,12 @@ static int __init pseries_cpu_hotplug_init(void)
> /* Processors can be added/removed only on LPAR */
> if (firmware_has_feature(FW_FEATURE_LPAR)) {
> for_each_node(node) {
> - alloc_bootmem_cpumask_var(&node_recorded_ids_map[node]);
> + alloc_cpumask_var(&node_recorded_ids_map[node],
> + GFP_KERNEL|GFP_NOWAIT);
This isn't atomic context, so GFP_KERNEL alone should be used.
Otherwise this change looks right to me.
>
> /* Record ids of CPU added at boot time */
> - cpumask_or(node_recorded_ids_map[node],
> - node_recorded_ids_map[node],
> - cpumask_of_node(node));
> + cpumask_copy(node_recorded_ids_map[node],
> + cpumask_of_node(node));
> }
>
> of_reconfig_notifier_register(&pseries_smp_nb);
> --
> 2.27.0
On 11/8/21 18:06, Nathan Lynch wrote:
> Waiman Long <[email protected]> writes:
>
>> It was found that the following warning message could be printed out when
>> booting the kernel on PowerPC systems that support LPAR:
>>
>> [ 0.129584] WARNING: CPU: 0 PID: 1 at mm/memblock.c:1451 memblock_alloc_internal+0x5c/0x104
>> [ 0.129593] Modules linked in:
>> [ 0.129598] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.14.0-11.el9.ppc64le+debug #1
>> [ 0.129605] NIP: c000000002040134 LR: c00000000204011c CTR: c0000000020241a8
>> [ 0.129610] REGS: c000000005637760 TRAP: 0700 Not tainted (5.14.0-11.el9.ppc64le+debug)
>> [ 0.129616] MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 48000222 XER: 00000002
>> [ 0.129635] CFAR: c0000000004d1cf4 IRQMASK: 0
>> [ 0.129635] GPR00: c00000000204011c c000000005637a00 c000000002c94d00 0000000000000001
>> [ 0.129635] GPR04: 0000000000000080 0000000000000000 0000000000000000 ffffffffffffffff
>> [ 0.129635] GPR08: 0000000000000000 0000000000000003 c00000000205ac64 0000000000080000
>> [ 0.129635] GPR12: 0000000000000000 c0000000049d0000 c000000000013078 0000000000000000
>> [ 0.129635] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
>> [ 0.129635] GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
>> [ 0.129635] GPR24: c000000002003808 c00000000146f7b8 0000000000000000 0000000000000100
>> [ 0.129635] GPR28: c000000002d7cf80 0000000000000000 0000000000000008 0000000000000000
>> [ 0.129710] NIP [c000000002040134] memblock_alloc_internal+0x5c/0x104
>> [ 0.129717] LR [c00000000204011c] memblock_alloc_internal+0x44/0x104
>> [ 0.129723] Call Trace:
>> [ 0.129726] [c000000005637a00] [c000000005637a40] 0xc000000005637a40 (unreliable)
>> [ 0.129735] [c000000005637a60] [c0000000020404d8] memblock_alloc_try_nid+0x94/0xcc
>> [ 0.129743] [c000000005637af0] [c00000000205ac64] alloc_bootmem_cpumask_var+0x4c/0x9c
>> [ 0.129751] [c000000005637b60] [c0000000020242e0] __machine_initcall_pseries_pseries_cpu_hotplug_init+0x138/0x1d8
>> [ 0.129760] [c000000005637bf0] [c000000000012404] do_one_initcall+0xa4/0x4f0
>> [ 0.129768] [c000000005637cd0] [c000000002005358] do_initcalls+0x140/0x18c
>> [ 0.129776] [c000000005637d80] [c0000000020055b8] kernel_init_freeable+0x178/0x1d0
>> [ 0.129783] [c000000005637db0] [c0000000000130a0] kernel_init+0x30/0x190
>> [ 0.129790] [c000000005637e10] [c00000000000cef4] ret_from_kernel_thread+0x5c/0x64
>>
>> The warning is printed in memblock_alloc_internal() because the slab
>> has been initialized when the initcalls are being processed.
> Looks like CONFIG_CPUMASK_OFFSTACK=y is necessary for the warning to
> trigger... guess that explains how it's escaped notice.
>
>> To
>> avoid the warning, change alloc_bootmem_cpumask_var() call in
>> pseries_cpu_hotplug_init() to alloc_cpumask_var() instead. Also
>> change cpumask_or() to cpumask_copy() or we will have to use
>> zalloc_cpumask_var().
> Makes sense.
>
>
>> Fixes: bd1dd4c5f528 ("powerpc/pseries: Prevent free CPU ids being reused on another node")
>> Signed-off-by: Waiman Long <[email protected]>
>> ---
>> arch/powerpc/platforms/pseries/hotplug-cpu.c | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
>> index 5ab44600c8d3..e8e08d916b16 100644
>> --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
>> +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
>> @@ -864,12 +864,12 @@ static int __init pseries_cpu_hotplug_init(void)
>> /* Processors can be added/removed only on LPAR */
>> if (firmware_has_feature(FW_FEATURE_LPAR)) {
>> for_each_node(node) {
>> - alloc_bootmem_cpumask_var(&node_recorded_ids_map[node]);
>> + alloc_cpumask_var(&node_recorded_ids_map[node],
>> + GFP_KERNEL|GFP_NOWAIT);
> This isn't atomic context, so GFP_KERNEL alone should be used.
>
> Otherwise this change looks right to me.
I added GFP_NOWAIT because the kzalloc_node() call from
memblock_alloc_internal() uses GFP_NOWAIT. That makes sense as you don't
want to wait in an initcall. Anyway, that shouldn't really matter as
there should be enough free memory at bootup time to satisfy the request
without waiting. So GFP_NOWAIT may not be necessary.
Cheers,
Longman
Excerpts from Michael Ellerman's message of November 9, 2021 11:04 am:
> Waiman Long <[email protected]> writes:
>> It was found that the following warning message could be printed out when
>> booting the kernel on PowerPC systems that support LPAR:
>>
>> [ 0.129584] WARNING: CPU: 0 PID: 1 at mm/memblock.c:1451 memblock_alloc_internal+0x5c/0x104
>> [ 0.129593] Modules linked in:
>> [ 0.129598] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.14.0-11.el9.ppc64le+debug #1
>> [ 0.129605] NIP: c000000002040134 LR: c00000000204011c CTR: c0000000020241a8
>> [ 0.129610] REGS: c000000005637760 TRAP: 0700 Not tainted (5.14.0-11.el9.ppc64le+debug)
>> [ 0.129616] MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 48000222 XER: 00000002
>> [ 0.129635] CFAR: c0000000004d1cf4 IRQMASK: 0
>> [ 0.129635] GPR00: c00000000204011c c000000005637a00 c000000002c94d00 0000000000000001
>> [ 0.129635] GPR04: 0000000000000080 0000000000000000 0000000000000000 ffffffffffffffff
>> [ 0.129635] GPR08: 0000000000000000 0000000000000003 c00000000205ac64 0000000000080000
>> [ 0.129635] GPR12: 0000000000000000 c0000000049d0000 c000000000013078 0000000000000000
>> [ 0.129635] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
>> [ 0.129635] GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
>> [ 0.129635] GPR24: c000000002003808 c00000000146f7b8 0000000000000000 0000000000000100
>> [ 0.129635] GPR28: c000000002d7cf80 0000000000000000 0000000000000008 0000000000000000
>> [ 0.129710] NIP [c000000002040134] memblock_alloc_internal+0x5c/0x104
>> [ 0.129717] LR [c00000000204011c] memblock_alloc_internal+0x44/0x104
>> [ 0.129723] Call Trace:
>> [ 0.129726] [c000000005637a00] [c000000005637a40] 0xc000000005637a40 (unreliable)
>> [ 0.129735] [c000000005637a60] [c0000000020404d8] memblock_alloc_try_nid+0x94/0xcc
>> [ 0.129743] [c000000005637af0] [c00000000205ac64] alloc_bootmem_cpumask_var+0x4c/0x9c
>> [ 0.129751] [c000000005637b60] [c0000000020242e0] __machine_initcall_pseries_pseries_cpu_hotplug_init+0x138/0x1d8
>> [ 0.129760] [c000000005637bf0] [c000000000012404] do_one_initcall+0xa4/0x4f0
>> [ 0.129768] [c000000005637cd0] [c000000002005358] do_initcalls+0x140/0x18c
>> [ 0.129776] [c000000005637d80] [c0000000020055b8] kernel_init_freeable+0x178/0x1d0
>> [ 0.129783] [c000000005637db0] [c0000000000130a0] kernel_init+0x30/0x190
>> [ 0.129790] [c000000005637e10] [c00000000000cef4] ret_from_kernel_thread+0x5c/0x64
>>
>> The warning is printed in memblock_alloc_internal() because the slab
>> has been initialized when the initcalls are being processed. To
>> avoid the warning, change alloc_bootmem_cpumask_var() call in
>> pseries_cpu_hotplug_init() to alloc_cpumask_var() instead. Also
>> change cpumask_or() to cpumask_copy() or we will have to use
>> zalloc_cpumask_var().
>>
>> Fixes: bd1dd4c5f528 ("powerpc/pseries: Prevent free CPU ids being reused on another node")
>> Signed-off-by: Waiman Long <[email protected]>
>> ---
>> arch/powerpc/platforms/pseries/hotplug-cpu.c | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>
>
> This looks similar to the patch Nick sent recently:
>
> https://lore.kernel.org/linuxppc-dev/[email protected]/
Ah, you get CONFIG_CPUMASK_OFFSTACK=y if CONFIG_DEBUG_PER_CPU_MAPS=y.
I was wondering how Waiman found it.
Differences between the two patches are error checking - no big deal but
we should just do it. And GFP_NOWAIT - is this required here?
Thanks,
Nick
On 11/8/21 20:04, Michael Ellerman wrote:
> Waiman Long <[email protected]> writes:
>> It was found that the following warning message could be printed out when
>> booting the kernel on PowerPC systems that support LPAR:
>>
>> [ 0.129584] WARNING: CPU: 0 PID: 1 at mm/memblock.c:1451 memblock_alloc_internal+0x5c/0x104
>> [ 0.129593] Modules linked in:
>> [ 0.129598] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.14.0-11.el9.ppc64le+debug #1
>> [ 0.129605] NIP: c000000002040134 LR: c00000000204011c CTR: c0000000020241a8
>> [ 0.129610] REGS: c000000005637760 TRAP: 0700 Not tainted (5.14.0-11.el9.ppc64le+debug)
>> [ 0.129616] MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 48000222 XER: 00000002
>> [ 0.129635] CFAR: c0000000004d1cf4 IRQMASK: 0
>> [ 0.129635] GPR00: c00000000204011c c000000005637a00 c000000002c94d00 0000000000000001
>> [ 0.129635] GPR04: 0000000000000080 0000000000000000 0000000000000000 ffffffffffffffff
>> [ 0.129635] GPR08: 0000000000000000 0000000000000003 c00000000205ac64 0000000000080000
>> [ 0.129635] GPR12: 0000000000000000 c0000000049d0000 c000000000013078 0000000000000000
>> [ 0.129635] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
>> [ 0.129635] GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
>> [ 0.129635] GPR24: c000000002003808 c00000000146f7b8 0000000000000000 0000000000000100
>> [ 0.129635] GPR28: c000000002d7cf80 0000000000000000 0000000000000008 0000000000000000
>> [ 0.129710] NIP [c000000002040134] memblock_alloc_internal+0x5c/0x104
>> [ 0.129717] LR [c00000000204011c] memblock_alloc_internal+0x44/0x104
>> [ 0.129723] Call Trace:
>> [ 0.129726] [c000000005637a00] [c000000005637a40] 0xc000000005637a40 (unreliable)
>> [ 0.129735] [c000000005637a60] [c0000000020404d8] memblock_alloc_try_nid+0x94/0xcc
>> [ 0.129743] [c000000005637af0] [c00000000205ac64] alloc_bootmem_cpumask_var+0x4c/0x9c
>> [ 0.129751] [c000000005637b60] [c0000000020242e0] __machine_initcall_pseries_pseries_cpu_hotplug_init+0x138/0x1d8
>> [ 0.129760] [c000000005637bf0] [c000000000012404] do_one_initcall+0xa4/0x4f0
>> [ 0.129768] [c000000005637cd0] [c000000002005358] do_initcalls+0x140/0x18c
>> [ 0.129776] [c000000005637d80] [c0000000020055b8] kernel_init_freeable+0x178/0x1d0
>> [ 0.129783] [c000000005637db0] [c0000000000130a0] kernel_init+0x30/0x190
>> [ 0.129790] [c000000005637e10] [c00000000000cef4] ret_from_kernel_thread+0x5c/0x64
>>
>> The warning is printed in memblock_alloc_internal() because the slab
>> has been initialized when the initcalls are being processed. To
>> avoid the warning, change alloc_bootmem_cpumask_var() call in
>> pseries_cpu_hotplug_init() to alloc_cpumask_var() instead. Also
>> change cpumask_or() to cpumask_copy() or we will have to use
>> zalloc_cpumask_var().
>>
>> Fixes: bd1dd4c5f528 ("powerpc/pseries: Prevent free CPU ids being reused on another node")
>> Signed-off-by: Waiman Long <[email protected]>
>> ---
>> arch/powerpc/platforms/pseries/hotplug-cpu.c | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> This looks similar to the patch Nick sent recently:
>
> https://lore.kernel.org/linuxppc-dev/[email protected]/
I was not aware of Nick's patch. Since a fix is pending, I am
withdrawing mime.
Cheers,
Longman
Waiman Long <[email protected]> writes:
> On 11/8/21 20:46, Nicholas Piggin wrote:
>> Differences between the two patches are error checking - no big deal but
>> we should just do it. And GFP_NOWAIT - is this required here?
>
> As I have replied in another thread, I added it because it was used in
> memblock_alloc_internal().
From the pseries code's point of view, that's an incidental property of
the misuse detection branch in memblock_alloc_internal() -- I'd
speculate to make it robust for calls from atomic context. GFP_NOWAIT is
not needed here.