Re: [PATCH v3] pseries/drmem: update LMBs after LPM
Le 03/05/2021 à 22:44, Tyrel Datwyler a écrit : On 5/3/21 10:28 AM, Laurent Dufour wrote: Le 01/05/2021 à 01:58, Tyrel Datwyler a écrit : On 4/30/21 9:13 AM, Laurent Dufour wrote: Le 29/04/2021 à 21:12, Tyrel Datwyler a écrit : On 4/29/21 3:27 AM, Aneesh Kumar K.V wrote: Laurent Dufour writes: Snip As of today I don't have a problem with your patch. This was more of me pointing out things that I think are currently wrong with our memory hotplug implementation, and that we need to take a long hard look at it down the road. I do agree, there is a lot of odd things there to address in this area. If you're ok with that patch, do you mind to add a reviewed-by? Can you send a v4 with the fix for the duplicate update included? Of course ! I wrote it last week, but let in the to-be-sent list, my mistake.
Re: [PATCH v3] pseries/drmem: update LMBs after LPM
On 5/3/21 10:28 AM, Laurent Dufour wrote: > Le 01/05/2021 à 01:58, Tyrel Datwyler a écrit : >> On 4/30/21 9:13 AM, Laurent Dufour wrote: >>> Le 29/04/2021 à 21:12, Tyrel Datwyler a écrit : On 4/29/21 3:27 AM, Aneesh Kumar K.V wrote: > Laurent Dufour writes: > Snip >> >> As of today I don't have a problem with your patch. This was more of me >> pointing >> out things that I think are currently wrong with our memory hotplug >> implementation, and that we need to take a long hard look at it down the >> road. > > I do agree, there is a lot of odd things there to address in this area. > If you're ok with that patch, do you mind to add a reviewed-by? > Can you send a v4 with the fix for the duplicate update included? -Tyrel
Re: [PATCH v3] pseries/drmem: update LMBs after LPM
Le 01/05/2021 à 01:58, Tyrel Datwyler a écrit :
On 4/30/21 9:13 AM, Laurent Dufour wrote:
Le 29/04/2021 à 21:12, Tyrel Datwyler a écrit :
On 4/29/21 3:27 AM, Aneesh Kumar K.V wrote:
Laurent Dufour writes:
After a LPM, the device tree node ibm,dynamic-reconfiguration-memory may be
updated by the hypervisor in the case the NUMA topology of the LPAR's
memory is updated.
This is caught by the kernel, but the memory's node is updated because
there is no way to move a memory block between nodes.
If later a memory block is added or removed, drmem_update_dt() is called
and it is overwriting the DT node to match the added or removed LMB. But
the LMB's associativity node has not been updated after the DT node update
and thus the node is overwritten by the Linux's topology instead of the
hypervisor one.
Introduce a hook called when the ibm,dynamic-reconfiguration-memory node is
updated to force an update of the LMB's associativity.
Cc: Tyrel Datwyler
Signed-off-by: Laurent Dufour
---
V3:
- Check rd->dn->name instead of rd->dn->full_name
V2:
- Take Tyrel's idea to rely on OF_RECONFIG_UPDATE_PROPERTY instead of
introducing a new hook mechanism.
---
arch/powerpc/include/asm/drmem.h | 1 +
arch/powerpc/mm/drmem.c | 35 +++
.../platforms/pseries/hotplug-memory.c | 4 +++
3 files changed, 40 insertions(+)
diff --git a/arch/powerpc/include/asm/drmem.h
b/arch/powerpc/include/asm/drmem.h
index bf2402fed3e0..4265d5e95c2c 100644
--- a/arch/powerpc/include/asm/drmem.h
+++ b/arch/powerpc/include/asm/drmem.h
@@ -111,6 +111,7 @@ int drmem_update_dt(void);
int __init
walk_drmem_lmbs_early(unsigned long node, void *data,
int (*func)(struct drmem_lmb *, const __be32 **, void *));
+void drmem_update_lmbs(struct property *prop);
#endif
static inline void invalidate_lmb_associativity_index(struct drmem_lmb
*lmb)
diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
index 9af3832c9d8d..f0a6633132af 100644
--- a/arch/powerpc/mm/drmem.c
+++ b/arch/powerpc/mm/drmem.c
@@ -307,6 +307,41 @@ int __init walk_drmem_lmbs_early(unsigned long node,
void *data,
return ret;
}
+/*
+ * Update the LMB associativity index.
+ */
+static int update_lmb(struct drmem_lmb *updated_lmb,
+ __maybe_unused const __be32 **usm,
+ __maybe_unused void *data)
+{
+ struct drmem_lmb *lmb;
+
+ /*
+ * Brut force there may be better way to fetch the LMB
+ */
+ for_each_drmem_lmb(lmb) {
+ if (lmb->drc_index != updated_lmb->drc_index)
+ continue;
+
+ lmb->aa_index = updated_lmb->aa_index;
+ break;
+ }
+ return 0;
+}
+
+/*
+ * Update the LMB associativity index.
+ *
+ * This needs to be called when the hypervisor is updating the
+ * dynamic-reconfiguration-memory node property.
+ */
+void drmem_update_lmbs(struct property *prop)
+{
+ if (!strcmp(prop->name, "ibm,dynamic-memory"))
+ __walk_drmem_v1_lmbs(prop->value, NULL, NULL, update_lmb);
+ else if (!strcmp(prop->name, "ibm,dynamic-memory-v2"))
+ __walk_drmem_v2_lmbs(prop->value, NULL, NULL, update_lmb);
+}
#endif
static int init_drmem_lmb_size(struct device_node *dn)
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 8377f1f7c78e..672ffbee2e78 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -949,6 +949,10 @@ static int pseries_memory_notifier(struct
notifier_block *nb,
case OF_RECONFIG_DETACH_NODE:
err = pseries_remove_mem_node(rd->dn);
break;
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ if (!strcmp(rd->dn->name,
+ "ibm,dynamic-reconfiguration-memory"))
+ drmem_update_lmbs(rd->prop);
}
return notifier_from_errno(err);
How will this interact with DLPAR memory? When we dlpar memory,
ibm,configure-connector is used to fetch the new associativity details
and set drmem_lmb->aa_index correctly there. Once that is done kernel
then call drmem_update_dt() which will result in the above notifier
callback?
IIUC, the call back then will update drmem_lmb->aa_index again?
After digging through some of this code I'm a bit concerned about all the kernel
device tree manipulation around memory DLPAR both with the assoc-lookup-array
prop update and post dynamic-memory prop updating. We build a drmem_info array
of the LMBs from the device-tree at boot. I don't really understand why we are
manipulating the device tree property every time we add/remove an LMB. Not sure
the reasoning was to write back in particular the aa_index and flags for each
LMB into the device tree when we already have them in the drmem_info array. On
the other hand the assoc-lookup-array I suppose would need to have an in kernel
representation to avoid updating the device tree property every time.
I think the rea
Re: [PATCH v3] pseries/drmem: update LMBs after LPM
On 4/30/21 9:13 AM, Laurent Dufour wrote:
> Le 29/04/2021 à 21:12, Tyrel Datwyler a écrit :
>> On 4/29/21 3:27 AM, Aneesh Kumar K.V wrote:
>>> Laurent Dufour writes:
>>>
After a LPM, the device tree node ibm,dynamic-reconfiguration-memory may be
updated by the hypervisor in the case the NUMA topology of the LPAR's
memory is updated.
This is caught by the kernel, but the memory's node is updated because
there is no way to move a memory block between nodes.
If later a memory block is added or removed, drmem_update_dt() is called
and it is overwriting the DT node to match the added or removed LMB. But
the LMB's associativity node has not been updated after the DT node update
and thus the node is overwritten by the Linux's topology instead of the
hypervisor one.
Introduce a hook called when the ibm,dynamic-reconfiguration-memory node is
updated to force an update of the LMB's associativity.
Cc: Tyrel Datwyler
Signed-off-by: Laurent Dufour
---
V3:
- Check rd->dn->name instead of rd->dn->full_name
V2:
- Take Tyrel's idea to rely on OF_RECONFIG_UPDATE_PROPERTY instead of
introducing a new hook mechanism.
---
arch/powerpc/include/asm/drmem.h | 1 +
arch/powerpc/mm/drmem.c | 35 +++
.../platforms/pseries/hotplug-memory.c | 4 +++
3 files changed, 40 insertions(+)
diff --git a/arch/powerpc/include/asm/drmem.h
b/arch/powerpc/include/asm/drmem.h
index bf2402fed3e0..4265d5e95c2c 100644
--- a/arch/powerpc/include/asm/drmem.h
+++ b/arch/powerpc/include/asm/drmem.h
@@ -111,6 +111,7 @@ int drmem_update_dt(void);
int __init
walk_drmem_lmbs_early(unsigned long node, void *data,
int (*func)(struct drmem_lmb *, const __be32 **, void *));
+void drmem_update_lmbs(struct property *prop);
#endif
static inline void invalidate_lmb_associativity_index(struct drmem_lmb
*lmb)
diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
index 9af3832c9d8d..f0a6633132af 100644
--- a/arch/powerpc/mm/drmem.c
+++ b/arch/powerpc/mm/drmem.c
@@ -307,6 +307,41 @@ int __init walk_drmem_lmbs_early(unsigned long node,
void *data,
return ret;
}
+/*
+ * Update the LMB associativity index.
+ */
+static int update_lmb(struct drmem_lmb *updated_lmb,
+ __maybe_unused const __be32 **usm,
+ __maybe_unused void *data)
+{
+ struct drmem_lmb *lmb;
+
+ /*
+ * Brut force there may be better way to fetch the LMB
+ */
+ for_each_drmem_lmb(lmb) {
+ if (lmb->drc_index != updated_lmb->drc_index)
+ continue;
+
+ lmb->aa_index = updated_lmb->aa_index;
+ break;
+ }
+ return 0;
+}
+
+/*
+ * Update the LMB associativity index.
+ *
+ * This needs to be called when the hypervisor is updating the
+ * dynamic-reconfiguration-memory node property.
+ */
+void drmem_update_lmbs(struct property *prop)
+{
+ if (!strcmp(prop->name, "ibm,dynamic-memory"))
+ __walk_drmem_v1_lmbs(prop->value, NULL, NULL, update_lmb);
+ else if (!strcmp(prop->name, "ibm,dynamic-memory-v2"))
+ __walk_drmem_v2_lmbs(prop->value, NULL, NULL, update_lmb);
+}
#endif
static int init_drmem_lmb_size(struct device_node *dn)
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 8377f1f7c78e..672ffbee2e78 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -949,6 +949,10 @@ static int pseries_memory_notifier(struct
notifier_block *nb,
case OF_RECONFIG_DETACH_NODE:
err = pseries_remove_mem_node(rd->dn);
break;
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ if (!strcmp(rd->dn->name,
+ "ibm,dynamic-reconfiguration-memory"))
+ drmem_update_lmbs(rd->prop);
}
return notifier_from_errno(err);
>>>
>>> How will this interact with DLPAR memory? When we dlpar memory,
>>> ibm,configure-connector is used to fetch the new associativity details
>>> and set drmem_lmb->aa_index correctly there. Once that is done kernel
>>> then call drmem_update_dt() which will result in the above notifier
>>> callback?
>>>
>>> IIUC, the call back then will update drmem_lmb->aa_index again?
>>
>> After digging through some of this code I'm a bit concerned about all the
>> kernel
>> device tree manipulation around memory DLPAR both with the assoc-lookup-array
>> prop update and post dynamic-memory prop updating. We build a dr
Re: [PATCH v3] pseries/drmem: update LMBs after LPM
Le 29/04/2021 à 21:12, Tyrel Datwyler a écrit :
On 4/29/21 3:27 AM, Aneesh Kumar K.V wrote:
Laurent Dufour writes:
After a LPM, the device tree node ibm,dynamic-reconfiguration-memory may be
updated by the hypervisor in the case the NUMA topology of the LPAR's
memory is updated.
This is caught by the kernel, but the memory's node is updated because
there is no way to move a memory block between nodes.
If later a memory block is added or removed, drmem_update_dt() is called
and it is overwriting the DT node to match the added or removed LMB. But
the LMB's associativity node has not been updated after the DT node update
and thus the node is overwritten by the Linux's topology instead of the
hypervisor one.
Introduce a hook called when the ibm,dynamic-reconfiguration-memory node is
updated to force an update of the LMB's associativity.
Cc: Tyrel Datwyler
Signed-off-by: Laurent Dufour
---
V3:
- Check rd->dn->name instead of rd->dn->full_name
V2:
- Take Tyrel's idea to rely on OF_RECONFIG_UPDATE_PROPERTY instead of
introducing a new hook mechanism.
---
arch/powerpc/include/asm/drmem.h | 1 +
arch/powerpc/mm/drmem.c | 35 +++
.../platforms/pseries/hotplug-memory.c| 4 +++
3 files changed, 40 insertions(+)
diff --git a/arch/powerpc/include/asm/drmem.h b/arch/powerpc/include/asm/drmem.h
index bf2402fed3e0..4265d5e95c2c 100644
--- a/arch/powerpc/include/asm/drmem.h
+++ b/arch/powerpc/include/asm/drmem.h
@@ -111,6 +111,7 @@ int drmem_update_dt(void);
int __init
walk_drmem_lmbs_early(unsigned long node, void *data,
int (*func)(struct drmem_lmb *, const __be32 **, void *));
+void drmem_update_lmbs(struct property *prop);
#endif
static inline void invalidate_lmb_associativity_index(struct drmem_lmb *lmb)
diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
index 9af3832c9d8d..f0a6633132af 100644
--- a/arch/powerpc/mm/drmem.c
+++ b/arch/powerpc/mm/drmem.c
@@ -307,6 +307,41 @@ int __init walk_drmem_lmbs_early(unsigned long node, void
*data,
return ret;
}
+/*
+ * Update the LMB associativity index.
+ */
+static int update_lmb(struct drmem_lmb *updated_lmb,
+ __maybe_unused const __be32 **usm,
+ __maybe_unused void *data)
+{
+ struct drmem_lmb *lmb;
+
+ /*
+* Brut force there may be better way to fetch the LMB
+*/
+ for_each_drmem_lmb(lmb) {
+ if (lmb->drc_index != updated_lmb->drc_index)
+ continue;
+
+ lmb->aa_index = updated_lmb->aa_index;
+ break;
+ }
+ return 0;
+}
+
+/*
+ * Update the LMB associativity index.
+ *
+ * This needs to be called when the hypervisor is updating the
+ * dynamic-reconfiguration-memory node property.
+ */
+void drmem_update_lmbs(struct property *prop)
+{
+ if (!strcmp(prop->name, "ibm,dynamic-memory"))
+ __walk_drmem_v1_lmbs(prop->value, NULL, NULL, update_lmb);
+ else if (!strcmp(prop->name, "ibm,dynamic-memory-v2"))
+ __walk_drmem_v2_lmbs(prop->value, NULL, NULL, update_lmb);
+}
#endif
static int init_drmem_lmb_size(struct device_node *dn)
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 8377f1f7c78e..672ffbee2e78 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -949,6 +949,10 @@ static int pseries_memory_notifier(struct notifier_block
*nb,
case OF_RECONFIG_DETACH_NODE:
err = pseries_remove_mem_node(rd->dn);
break;
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ if (!strcmp(rd->dn->name,
+ "ibm,dynamic-reconfiguration-memory"))
+ drmem_update_lmbs(rd->prop);
}
return notifier_from_errno(err);
How will this interact with DLPAR memory? When we dlpar memory,
ibm,configure-connector is used to fetch the new associativity details
and set drmem_lmb->aa_index correctly there. Once that is done kernel
then call drmem_update_dt() which will result in the above notifier
callback?
IIUC, the call back then will update drmem_lmb->aa_index again?
After digging through some of this code I'm a bit concerned about all the kernel
device tree manipulation around memory DLPAR both with the assoc-lookup-array
prop update and post dynamic-memory prop updating. We build a drmem_info array
of the LMBs from the device-tree at boot. I don't really understand why we are
manipulating the device tree property every time we add/remove an LMB. Not sure
the reasoning was to write back in particular the aa_index and flags for each
LMB into the device tree when we already have them in the drmem_info array. On
the other hand the assoc-lookup-array I suppose would need to have an in kernel
representation to avoid updating the device tre
Re: [PATCH v3] pseries/drmem: update LMBs after LPM
On 4/29/21 3:27 AM, Aneesh Kumar K.V wrote:
> Laurent Dufour writes:
>
>> After a LPM, the device tree node ibm,dynamic-reconfiguration-memory may be
>> updated by the hypervisor in the case the NUMA topology of the LPAR's
>> memory is updated.
>>
>> This is caught by the kernel, but the memory's node is updated because
>> there is no way to move a memory block between nodes.
>>
>> If later a memory block is added or removed, drmem_update_dt() is called
>> and it is overwriting the DT node to match the added or removed LMB. But
>> the LMB's associativity node has not been updated after the DT node update
>> and thus the node is overwritten by the Linux's topology instead of the
>> hypervisor one.
>>
>> Introduce a hook called when the ibm,dynamic-reconfiguration-memory node is
>> updated to force an update of the LMB's associativity.
>>
>> Cc: Tyrel Datwyler
>> Signed-off-by: Laurent Dufour
>> ---
>>
>> V3:
>> - Check rd->dn->name instead of rd->dn->full_name
>> V2:
>> - Take Tyrel's idea to rely on OF_RECONFIG_UPDATE_PROPERTY instead of
>> introducing a new hook mechanism.
>> ---
>> arch/powerpc/include/asm/drmem.h | 1 +
>> arch/powerpc/mm/drmem.c | 35 +++
>> .../platforms/pseries/hotplug-memory.c| 4 +++
>> 3 files changed, 40 insertions(+)
>>
>> diff --git a/arch/powerpc/include/asm/drmem.h
>> b/arch/powerpc/include/asm/drmem.h
>> index bf2402fed3e0..4265d5e95c2c 100644
>> --- a/arch/powerpc/include/asm/drmem.h
>> +++ b/arch/powerpc/include/asm/drmem.h
>> @@ -111,6 +111,7 @@ int drmem_update_dt(void);
>> int __init
>> walk_drmem_lmbs_early(unsigned long node, void *data,
>>int (*func)(struct drmem_lmb *, const __be32 **, void *));
>> +void drmem_update_lmbs(struct property *prop);
>> #endif
>>
>> static inline void invalidate_lmb_associativity_index(struct drmem_lmb *lmb)
>> diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
>> index 9af3832c9d8d..f0a6633132af 100644
>> --- a/arch/powerpc/mm/drmem.c
>> +++ b/arch/powerpc/mm/drmem.c
>> @@ -307,6 +307,41 @@ int __init walk_drmem_lmbs_early(unsigned long node,
>> void *data,
>> return ret;
>> }
>>
>> +/*
>> + * Update the LMB associativity index.
>> + */
>> +static int update_lmb(struct drmem_lmb *updated_lmb,
>> + __maybe_unused const __be32 **usm,
>> + __maybe_unused void *data)
>> +{
>> +struct drmem_lmb *lmb;
>> +
>> +/*
>> + * Brut force there may be better way to fetch the LMB
>> + */
>> +for_each_drmem_lmb(lmb) {
>> +if (lmb->drc_index != updated_lmb->drc_index)
>> +continue;
>> +
>> +lmb->aa_index = updated_lmb->aa_index;
>> +break;
>> +}
>> +return 0;
>> +}
>> +
>> +/*
>> + * Update the LMB associativity index.
>> + *
>> + * This needs to be called when the hypervisor is updating the
>> + * dynamic-reconfiguration-memory node property.
>> + */
>> +void drmem_update_lmbs(struct property *prop)
>> +{
>> +if (!strcmp(prop->name, "ibm,dynamic-memory"))
>> +__walk_drmem_v1_lmbs(prop->value, NULL, NULL, update_lmb);
>> +else if (!strcmp(prop->name, "ibm,dynamic-memory-v2"))
>> +__walk_drmem_v2_lmbs(prop->value, NULL, NULL, update_lmb);
>> +}
>> #endif
>>
>> static int init_drmem_lmb_size(struct device_node *dn)
>> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
>> b/arch/powerpc/platforms/pseries/hotplug-memory.c
>> index 8377f1f7c78e..672ffbee2e78 100644
>> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
>> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
>> @@ -949,6 +949,10 @@ static int pseries_memory_notifier(struct
>> notifier_block *nb,
>> case OF_RECONFIG_DETACH_NODE:
>> err = pseries_remove_mem_node(rd->dn);
>> break;
>> +case OF_RECONFIG_UPDATE_PROPERTY:
>> +if (!strcmp(rd->dn->name,
>> +"ibm,dynamic-reconfiguration-memory"))
>> +drmem_update_lmbs(rd->prop);
>> }
>> return notifier_from_errno(err);
>
> How will this interact with DLPAR memory? When we dlpar memory,
> ibm,configure-connector is used to fetch the new associativity details
> and set drmem_lmb->aa_index correctly there. Once that is done kernel
> then call drmem_update_dt() which will result in the above notifier
> callback?
>
> IIUC, the call back then will update drmem_lmb->aa_index again?
After digging through some of this code I'm a bit concerned about all the kernel
device tree manipulation around memory DLPAR both with the assoc-lookup-array
prop update and post dynamic-memory prop updating. We build a drmem_info array
of the LMBs from the device-tree at boot. I don't really understand why we are
manipulating the device tree property every time we add/remove an LMB. Not sure
the reasoning was to write back in particular the aa_index and flags for each
LMB into the device tree wh
Re: [PATCH v3] pseries/drmem: update LMBs after LPM
Le 29/04/2021 à 12:27, Aneesh Kumar K.V a écrit :
Laurent Dufour writes:
After a LPM, the device tree node ibm,dynamic-reconfiguration-memory may be
updated by the hypervisor in the case the NUMA topology of the LPAR's
memory is updated.
This is caught by the kernel, but the memory's node is updated because
there is no way to move a memory block between nodes.
If later a memory block is added or removed, drmem_update_dt() is called
and it is overwriting the DT node to match the added or removed LMB. But
the LMB's associativity node has not been updated after the DT node update
and thus the node is overwritten by the Linux's topology instead of the
hypervisor one.
Introduce a hook called when the ibm,dynamic-reconfiguration-memory node is
updated to force an update of the LMB's associativity.
Cc: Tyrel Datwyler
Signed-off-by: Laurent Dufour
---
V3:
- Check rd->dn->name instead of rd->dn->full_name
V2:
- Take Tyrel's idea to rely on OF_RECONFIG_UPDATE_PROPERTY instead of
introducing a new hook mechanism.
---
arch/powerpc/include/asm/drmem.h | 1 +
arch/powerpc/mm/drmem.c | 35 +++
.../platforms/pseries/hotplug-memory.c| 4 +++
3 files changed, 40 insertions(+)
diff --git a/arch/powerpc/include/asm/drmem.h b/arch/powerpc/include/asm/drmem.h
index bf2402fed3e0..4265d5e95c2c 100644
--- a/arch/powerpc/include/asm/drmem.h
+++ b/arch/powerpc/include/asm/drmem.h
@@ -111,6 +111,7 @@ int drmem_update_dt(void);
int __init
walk_drmem_lmbs_early(unsigned long node, void *data,
int (*func)(struct drmem_lmb *, const __be32 **, void *));
+void drmem_update_lmbs(struct property *prop);
#endif
static inline void invalidate_lmb_associativity_index(struct drmem_lmb *lmb)
diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
index 9af3832c9d8d..f0a6633132af 100644
--- a/arch/powerpc/mm/drmem.c
+++ b/arch/powerpc/mm/drmem.c
@@ -307,6 +307,41 @@ int __init walk_drmem_lmbs_early(unsigned long node, void
*data,
return ret;
}
+/*
+ * Update the LMB associativity index.
+ */
+static int update_lmb(struct drmem_lmb *updated_lmb,
+ __maybe_unused const __be32 **usm,
+ __maybe_unused void *data)
+{
+ struct drmem_lmb *lmb;
+
+ /*
+* Brut force there may be better way to fetch the LMB
+*/
+ for_each_drmem_lmb(lmb) {
+ if (lmb->drc_index != updated_lmb->drc_index)
+ continue;
+
+ lmb->aa_index = updated_lmb->aa_index;
+ break;
+ }
+ return 0;
+}
+
+/*
+ * Update the LMB associativity index.
+ *
+ * This needs to be called when the hypervisor is updating the
+ * dynamic-reconfiguration-memory node property.
+ */
+void drmem_update_lmbs(struct property *prop)
+{
+ if (!strcmp(prop->name, "ibm,dynamic-memory"))
+ __walk_drmem_v1_lmbs(prop->value, NULL, NULL, update_lmb);
+ else if (!strcmp(prop->name, "ibm,dynamic-memory-v2"))
+ __walk_drmem_v2_lmbs(prop->value, NULL, NULL, update_lmb);
+}
#endif
static int init_drmem_lmb_size(struct device_node *dn)
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 8377f1f7c78e..672ffbee2e78 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -949,6 +949,10 @@ static int pseries_memory_notifier(struct notifier_block
*nb,
case OF_RECONFIG_DETACH_NODE:
err = pseries_remove_mem_node(rd->dn);
break;
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ if (!strcmp(rd->dn->name,
+ "ibm,dynamic-reconfiguration-memory"))
+ drmem_update_lmbs(rd->prop);
}
return notifier_from_errno(err);
How will this interact with DLPAR memory? When we dlpar memory,
ibm,configure-connector is used to fetch the new associativity details
and set drmem_lmb->aa_index correctly there. Once that is done kernel
then call drmem_update_dt() which will result in the above notifier
callback?
IIUC, the call back then will update drmem_lmb->aa_index again?
Thanks for pointing this Aneesh,
You're right I missed that callback and it was quite invisible during my test
because the value set back in the aa_index was the same.
When dmrem_update_dt() is called, there is no need to update the LMB back and
the DT modify notifier should be ignored.
As DLPAR operations are serialized (by lock_device_hotplug()), I'm proposing to
rely on a boolean static variable to do skip this notification, like this:
diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
index f0a6633132af..3c0130720086 100644
--- a/arch/powerpc/mm/drmem.c
+++ b/arch/powerpc/mm/drmem.c
@@ -18,6 +18,7 @@ static int n_root_addr_cells, n_root_size_cells;
static struct drmem_lmb_info __drmem_i
Re: [PATCH v3] pseries/drmem: update LMBs after LPM
Le 29/04/2021 à 13:31, Laurent Dufour a écrit :
Le 29/04/2021 à 12:27, Aneesh Kumar K.V a écrit :
Laurent Dufour writes:
After a LPM, the device tree node ibm,dynamic-reconfiguration-memory may be
updated by the hypervisor in the case the NUMA topology of the LPAR's
memory is updated.
This is caught by the kernel, but the memory's node is updated because
there is no way to move a memory block between nodes.
If later a memory block is added or removed, drmem_update_dt() is called
and it is overwriting the DT node to match the added or removed LMB. But
the LMB's associativity node has not been updated after the DT node update
and thus the node is overwritten by the Linux's topology instead of the
hypervisor one.
Introduce a hook called when the ibm,dynamic-reconfiguration-memory node is
updated to force an update of the LMB's associativity.
Cc: Tyrel Datwyler
Signed-off-by: Laurent Dufour
---
V3:
- Check rd->dn->name instead of rd->dn->full_name
V2:
- Take Tyrel's idea to rely on OF_RECONFIG_UPDATE_PROPERTY instead of
introducing a new hook mechanism.
---
arch/powerpc/include/asm/drmem.h | 1 +
arch/powerpc/mm/drmem.c | 35 +++
.../platforms/pseries/hotplug-memory.c | 4 +++
3 files changed, 40 insertions(+)
diff --git a/arch/powerpc/include/asm/drmem.h b/arch/powerpc/include/asm/drmem.h
index bf2402fed3e0..4265d5e95c2c 100644
--- a/arch/powerpc/include/asm/drmem.h
+++ b/arch/powerpc/include/asm/drmem.h
@@ -111,6 +111,7 @@ int drmem_update_dt(void);
int __init
walk_drmem_lmbs_early(unsigned long node, void *data,
int (*func)(struct drmem_lmb *, const __be32 **, void *));
+void drmem_update_lmbs(struct property *prop);
#endif
static inline void invalidate_lmb_associativity_index(struct drmem_lmb *lmb)
diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
index 9af3832c9d8d..f0a6633132af 100644
--- a/arch/powerpc/mm/drmem.c
+++ b/arch/powerpc/mm/drmem.c
@@ -307,6 +307,41 @@ int __init walk_drmem_lmbs_early(unsigned long node,
void *data,
return ret;
}
+/*
+ * Update the LMB associativity index.
+ */
+static int update_lmb(struct drmem_lmb *updated_lmb,
+ __maybe_unused const __be32 **usm,
+ __maybe_unused void *data)
+{
+ struct drmem_lmb *lmb;
+
+ /*
+ * Brut force there may be better way to fetch the LMB
+ */
+ for_each_drmem_lmb(lmb) {
+ if (lmb->drc_index != updated_lmb->drc_index)
+ continue;
+
+ lmb->aa_index = updated_lmb->aa_index;
+ break;
+ }
+ return 0;
+}
+
+/*
+ * Update the LMB associativity index.
+ *
+ * This needs to be called when the hypervisor is updating the
+ * dynamic-reconfiguration-memory node property.
+ */
+void drmem_update_lmbs(struct property *prop)
+{
+ if (!strcmp(prop->name, "ibm,dynamic-memory"))
+ __walk_drmem_v1_lmbs(prop->value, NULL, NULL, update_lmb);
+ else if (!strcmp(prop->name, "ibm,dynamic-memory-v2"))
+ __walk_drmem_v2_lmbs(prop->value, NULL, NULL, update_lmb);
+}
#endif
static int init_drmem_lmb_size(struct device_node *dn)
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 8377f1f7c78e..672ffbee2e78 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -949,6 +949,10 @@ static int pseries_memory_notifier(struct notifier_block
*nb,
case OF_RECONFIG_DETACH_NODE:
err = pseries_remove_mem_node(rd->dn);
break;
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ if (!strcmp(rd->dn->name,
+ "ibm,dynamic-reconfiguration-memory"))
+ drmem_update_lmbs(rd->prop);
}
return notifier_from_errno(err);
How will this interact with DLPAR memory? When we dlpar memory,
ibm,configure-connector is used to fetch the new associativity details
and set drmem_lmb->aa_index correctly there. Once that is done kernel
then call drmem_update_dt() which will result in the above notifier
callback?
When a memory DLPAR operation is done, the in memory DT property
"ibm,dynamic-memory" or "ibm,dynamic-memory-v2" (if existing) have to be updated
to reflect the added/removed memory part. This is done by calling
drmem_update_dt().
This patch is addressing the case where the hypervisor has updated the DT
property mentioned above. In that case, the LMB tree should be updated so the
aa_index fields are matching the DT one. This way the next time a memory DLPAR
operation is done the DT properties "ibm,dynamic-memory" or
"ibm,dynamic-memory-v2" will be rebuilt correctly.
IIUC, the call back then will update drmem_lmb->aa_index again?
Oh I missed what you pointed out.
Please ignore my previous answer, I need to double check code.
drmem_update_dt() is not updating drmem_lmb->aa_index, that's the oppposite, it
is rebuilding the in memory DT property "ibm,dynamic-memory" or
Re: [PATCH v3] pseries/drmem: update LMBs after LPM
Le 29/04/2021 à 12:27, Aneesh Kumar K.V a écrit :
Laurent Dufour writes:
After a LPM, the device tree node ibm,dynamic-reconfiguration-memory may be
updated by the hypervisor in the case the NUMA topology of the LPAR's
memory is updated.
This is caught by the kernel, but the memory's node is updated because
there is no way to move a memory block between nodes.
If later a memory block is added or removed, drmem_update_dt() is called
and it is overwriting the DT node to match the added or removed LMB. But
the LMB's associativity node has not been updated after the DT node update
and thus the node is overwritten by the Linux's topology instead of the
hypervisor one.
Introduce a hook called when the ibm,dynamic-reconfiguration-memory node is
updated to force an update of the LMB's associativity.
Cc: Tyrel Datwyler
Signed-off-by: Laurent Dufour
---
V3:
- Check rd->dn->name instead of rd->dn->full_name
V2:
- Take Tyrel's idea to rely on OF_RECONFIG_UPDATE_PROPERTY instead of
introducing a new hook mechanism.
---
arch/powerpc/include/asm/drmem.h | 1 +
arch/powerpc/mm/drmem.c | 35 +++
.../platforms/pseries/hotplug-memory.c| 4 +++
3 files changed, 40 insertions(+)
diff --git a/arch/powerpc/include/asm/drmem.h b/arch/powerpc/include/asm/drmem.h
index bf2402fed3e0..4265d5e95c2c 100644
--- a/arch/powerpc/include/asm/drmem.h
+++ b/arch/powerpc/include/asm/drmem.h
@@ -111,6 +111,7 @@ int drmem_update_dt(void);
int __init
walk_drmem_lmbs_early(unsigned long node, void *data,
int (*func)(struct drmem_lmb *, const __be32 **, void *));
+void drmem_update_lmbs(struct property *prop);
#endif
static inline void invalidate_lmb_associativity_index(struct drmem_lmb *lmb)
diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
index 9af3832c9d8d..f0a6633132af 100644
--- a/arch/powerpc/mm/drmem.c
+++ b/arch/powerpc/mm/drmem.c
@@ -307,6 +307,41 @@ int __init walk_drmem_lmbs_early(unsigned long node, void
*data,
return ret;
}
+/*
+ * Update the LMB associativity index.
+ */
+static int update_lmb(struct drmem_lmb *updated_lmb,
+ __maybe_unused const __be32 **usm,
+ __maybe_unused void *data)
+{
+ struct drmem_lmb *lmb;
+
+ /*
+* Brut force there may be better way to fetch the LMB
+*/
+ for_each_drmem_lmb(lmb) {
+ if (lmb->drc_index != updated_lmb->drc_index)
+ continue;
+
+ lmb->aa_index = updated_lmb->aa_index;
+ break;
+ }
+ return 0;
+}
+
+/*
+ * Update the LMB associativity index.
+ *
+ * This needs to be called when the hypervisor is updating the
+ * dynamic-reconfiguration-memory node property.
+ */
+void drmem_update_lmbs(struct property *prop)
+{
+ if (!strcmp(prop->name, "ibm,dynamic-memory"))
+ __walk_drmem_v1_lmbs(prop->value, NULL, NULL, update_lmb);
+ else if (!strcmp(prop->name, "ibm,dynamic-memory-v2"))
+ __walk_drmem_v2_lmbs(prop->value, NULL, NULL, update_lmb);
+}
#endif
static int init_drmem_lmb_size(struct device_node *dn)
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 8377f1f7c78e..672ffbee2e78 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -949,6 +949,10 @@ static int pseries_memory_notifier(struct notifier_block
*nb,
case OF_RECONFIG_DETACH_NODE:
err = pseries_remove_mem_node(rd->dn);
break;
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ if (!strcmp(rd->dn->name,
+ "ibm,dynamic-reconfiguration-memory"))
+ drmem_update_lmbs(rd->prop);
}
return notifier_from_errno(err);
How will this interact with DLPAR memory? When we dlpar memory,
ibm,configure-connector is used to fetch the new associativity details
and set drmem_lmb->aa_index correctly there. Once that is done kernel
then call drmem_update_dt() which will result in the above notifier
callback?
When a memory DLPAR operation is done, the in memory DT property
"ibm,dynamic-memory" or "ibm,dynamic-memory-v2" (if existing) have to be updated
to reflect the added/removed memory part. This is done by calling drmem_update_dt().
This patch is addressing the case where the hypervisor has updated the DT
property mentioned above. In that case, the LMB tree should be updated so the
aa_index fields are matching the DT one. This way the next time a memory DLPAR
operation is done the DT properties "ibm,dynamic-memory" or
"ibm,dynamic-memory-v2" will be rebuilt correctly.
IIUC, the call back then will update drmem_lmb->aa_index again?
drmem_update_dt() is not updating drmem_lmb->aa_index, that's the oppposite, it
is rebuilding the in memory DT property "ibm,dynamic-memor
Re: [PATCH v3] pseries/drmem: update LMBs after LPM
Laurent Dufour writes:
> After a LPM, the device tree node ibm,dynamic-reconfiguration-memory may be
> updated by the hypervisor in the case the NUMA topology of the LPAR's
> memory is updated.
>
> This is caught by the kernel, but the memory's node is updated because
> there is no way to move a memory block between nodes.
>
> If later a memory block is added or removed, drmem_update_dt() is called
> and it is overwriting the DT node to match the added or removed LMB. But
> the LMB's associativity node has not been updated after the DT node update
> and thus the node is overwritten by the Linux's topology instead of the
> hypervisor one.
>
> Introduce a hook called when the ibm,dynamic-reconfiguration-memory node is
> updated to force an update of the LMB's associativity.
>
> Cc: Tyrel Datwyler
> Signed-off-by: Laurent Dufour
> ---
>
> V3:
> - Check rd->dn->name instead of rd->dn->full_name
> V2:
> - Take Tyrel's idea to rely on OF_RECONFIG_UPDATE_PROPERTY instead of
> introducing a new hook mechanism.
> ---
> arch/powerpc/include/asm/drmem.h | 1 +
> arch/powerpc/mm/drmem.c | 35 +++
> .../platforms/pseries/hotplug-memory.c| 4 +++
> 3 files changed, 40 insertions(+)
>
> diff --git a/arch/powerpc/include/asm/drmem.h
> b/arch/powerpc/include/asm/drmem.h
> index bf2402fed3e0..4265d5e95c2c 100644
> --- a/arch/powerpc/include/asm/drmem.h
> +++ b/arch/powerpc/include/asm/drmem.h
> @@ -111,6 +111,7 @@ int drmem_update_dt(void);
> int __init
> walk_drmem_lmbs_early(unsigned long node, void *data,
> int (*func)(struct drmem_lmb *, const __be32 **, void *));
> +void drmem_update_lmbs(struct property *prop);
> #endif
>
> static inline void invalidate_lmb_associativity_index(struct drmem_lmb *lmb)
> diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
> index 9af3832c9d8d..f0a6633132af 100644
> --- a/arch/powerpc/mm/drmem.c
> +++ b/arch/powerpc/mm/drmem.c
> @@ -307,6 +307,41 @@ int __init walk_drmem_lmbs_early(unsigned long node,
> void *data,
> return ret;
> }
>
> +/*
> + * Update the LMB associativity index.
> + */
> +static int update_lmb(struct drmem_lmb *updated_lmb,
> + __maybe_unused const __be32 **usm,
> + __maybe_unused void *data)
> +{
> + struct drmem_lmb *lmb;
> +
> + /*
> + * Brut force there may be better way to fetch the LMB
> + */
> + for_each_drmem_lmb(lmb) {
> + if (lmb->drc_index != updated_lmb->drc_index)
> + continue;
> +
> + lmb->aa_index = updated_lmb->aa_index;
> + break;
> + }
> + return 0;
> +}
> +
> +/*
> + * Update the LMB associativity index.
> + *
> + * This needs to be called when the hypervisor is updating the
> + * dynamic-reconfiguration-memory node property.
> + */
> +void drmem_update_lmbs(struct property *prop)
> +{
> + if (!strcmp(prop->name, "ibm,dynamic-memory"))
> + __walk_drmem_v1_lmbs(prop->value, NULL, NULL, update_lmb);
> + else if (!strcmp(prop->name, "ibm,dynamic-memory-v2"))
> + __walk_drmem_v2_lmbs(prop->value, NULL, NULL, update_lmb);
> +}
> #endif
>
> static int init_drmem_lmb_size(struct device_node *dn)
> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c
> b/arch/powerpc/platforms/pseries/hotplug-memory.c
> index 8377f1f7c78e..672ffbee2e78 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> @@ -949,6 +949,10 @@ static int pseries_memory_notifier(struct notifier_block
> *nb,
> case OF_RECONFIG_DETACH_NODE:
> err = pseries_remove_mem_node(rd->dn);
> break;
> + case OF_RECONFIG_UPDATE_PROPERTY:
> + if (!strcmp(rd->dn->name,
> + "ibm,dynamic-reconfiguration-memory"))
> + drmem_update_lmbs(rd->prop);
> }
> return notifier_from_errno(err);
How will this interact with DLPAR memory? When we dlpar memory,
ibm,configure-connector is used to fetch the new associativity details
and set drmem_lmb->aa_index correctly there. Once that is done kernel
then call drmem_update_dt() which will result in the above notifier
callback?
IIUC, the call back then will update drmem_lmb->aa_index again?
-aneesh
