Re: [PATCH -mm] mm, memory-hotpulg: Rename movablenode boot option to movable_node
Hello Ingo, On 10/01/2013 01:46 PM, Ingo Molnar wrote: > > * Zhang Yanfei wrote: > >> @@ -153,11 +153,18 @@ config MOVABLE_NODE >> help >>Allow a node to have only movable memory. Pages used by the kernel, >>such as direct mapping pages cannot be migrated. So the corresponding >> + memory device cannot be hotplugged. This option allows the following >> + two things: >> + - When the system is booting, node full of hotpluggable memory can >> + be arranged to have only movable memory so that the whole node can >> + be hotplugged. (need movable_node boot option specified). > > So this is _exactly_ what I complained about earlier: why is the > movable_node boot option needed to get that extra functionality? It's > clearly not just a drop-in substitute to CONFIG_MOVABLE_NODE but extends > its functionality, right? Generally speaking, CONFIG_MOVABLE_NODE is used to allow a node to have only movable memory. Firstly, we didn't support the functionality to support boot-time configuration. That said, before this patchset, we only support later hot-add node to have only movable memory but any node that is dectected at boot-time cannot. So here is movable_node option, to protect the kernel from using hotpluggable memory at boot-time and if a node is full of hotpluggable memory, this node is arranged to have only movable memory and can be hot-removed after the system is up. > > Boot options are _very_ poor user interface. If you don't want to enable > it by default then turn this sub-functionality into > CONFIG_MOVABLE_NODE_AUTO and keep it default-off - but don't pretend that > this is only about CONFIG_MOVABLE_NODE alone - it isnt: as described above > the 'movable_node' is needed for the full functionality to be available! As explained above, we need the boot option to only disable boot-time memory-hotplug configuration not the whole MOVABLE_NODE functionality. Thanks -- Thanks. Zhang Yanfei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm] mm, memory-hotpulg: Rename movablenode boot option to movable_node
Hello Ingo, On 10/01/2013 01:46 PM, Ingo Molnar wrote: * Zhang Yanfei zhangyanfei@gmail.com wrote: @@ -153,11 +153,18 @@ config MOVABLE_NODE help Allow a node to have only movable memory. Pages used by the kernel, such as direct mapping pages cannot be migrated. So the corresponding + memory device cannot be hotplugged. This option allows the following + two things: + - When the system is booting, node full of hotpluggable memory can + be arranged to have only movable memory so that the whole node can + be hotplugged. (need movable_node boot option specified). So this is _exactly_ what I complained about earlier: why is the movable_node boot option needed to get that extra functionality? It's clearly not just a drop-in substitute to CONFIG_MOVABLE_NODE but extends its functionality, right? Generally speaking, CONFIG_MOVABLE_NODE is used to allow a node to have only movable memory. Firstly, we didn't support the functionality to support boot-time configuration. That said, before this patchset, we only support later hot-add node to have only movable memory but any node that is dectected at boot-time cannot. So here is movable_node option, to protect the kernel from using hotpluggable memory at boot-time and if a node is full of hotpluggable memory, this node is arranged to have only movable memory and can be hot-removed after the system is up. Boot options are _very_ poor user interface. If you don't want to enable it by default then turn this sub-functionality into CONFIG_MOVABLE_NODE_AUTO and keep it default-off - but don't pretend that this is only about CONFIG_MOVABLE_NODE alone - it isnt: as described above the 'movable_node' is needed for the full functionality to be available! As explained above, we need the boot option to only disable boot-time memory-hotplug configuration not the whole MOVABLE_NODE functionality. Thanks -- Thanks. Zhang Yanfei -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm] mm, memory-hotpulg: Rename movablenode boot option to movable_node
* Zhang Yanfei wrote: > @@ -153,11 +153,18 @@ config MOVABLE_NODE > help > Allow a node to have only movable memory. Pages used by the kernel, > such as direct mapping pages cannot be migrated. So the corresponding > + memory device cannot be hotplugged. This option allows the following > + two things: > + - When the system is booting, node full of hotpluggable memory can > + be arranged to have only movable memory so that the whole node can > + be hotplugged. (need movable_node boot option specified). So this is _exactly_ what I complained about earlier: why is the movable_node boot option needed to get that extra functionality? It's clearly not just a drop-in substitute to CONFIG_MOVABLE_NODE but extends its functionality, right? Boot options are _very_ poor user interface. If you don't want to enable it by default then turn this sub-functionality into CONFIG_MOVABLE_NODE_AUTO and keep it default-off - but don't pretend that this is only about CONFIG_MOVABLE_NODE alone - it isnt: as described above the 'movable_node' is needed for the full functionality to be available! Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH -mm] mm, memory-hotpulg: Rename movablenode boot option to movable_node
From: Zhang Yanfei
Since we already has config MOVABLE_NODE, and the boot option
movablenode is introduced as the boot-time switch to disable
the effects of CONFIG_MOVABLE_NODE=y when the system is booting.
So rename boot option movablenode to movable_node to match the
config MOVABLE_NODE. And also updates the description of MOVABLE_NODE
in mm/Kconfig and the description of movable_node in kernel doc.
Suggested-by: Ingo Molnar
Signed-off-by: Zhang Yanfei
---
Documentation/kernel-parameters.txt | 16 ++--
mm/Kconfig | 17 -
mm/memory_hotplug.c |6 +++---
3 files changed, 17 insertions(+), 22 deletions(-)
diff --git a/Documentation/kernel-parameters.txt
b/Documentation/kernel-parameters.txt
index a87e17e..953a533 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1773,20 +1773,8 @@ bytes respectively. Such letter suffixes can also be
entirely omitted.
that the amount of memory usable for all allocations
is not too small.
- movablenode [KNL,X86] This parameter enables/disables the
- kernel to arrange hotpluggable memory ranges recorded
- in ACPI SRAT(System Resource Affinity Table) as
- ZONE_MOVABLE. And these memory can be hot-removed when
- the system is up.
- By specifying this option, all the hotpluggable memory
- will be in ZONE_MOVABLE, which the kernel cannot use.
- This will cause NUMA performance down. For users who
- care about NUMA performance, just don't use it.
- If all the memory ranges in the system are hotpluggable,
- then the ones used by the kernel at early time, such as
- kernel code and data segments, initrd file and so on,
- won't be set as ZONE_MOVABLE, and won't be hotpluggable.
- Otherwise the kernel won't have enough memory to boot.
+ movable_node[KNL,X86] Boot-time switch to disable the effects
+ of CONFIG_MOVABLE_NODE=y. See mm/Kconfig for details.
MTD_Partition= [MTD]
Format: ,,,
diff --git a/mm/Kconfig b/mm/Kconfig
index ff6e820..8d4ebb0 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -153,11 +153,18 @@ config MOVABLE_NODE
help
Allow a node to have only movable memory. Pages used by the kernel,
such as direct mapping pages cannot be migrated. So the corresponding
- memory device cannot be hotplugged. This option allows users to
- online all the memory of a node as movable memory so that the whole
- node can be hotplugged. Users who don't use the memory hotplug
- feature are fine with this option on since they don't online memory
- as movable.
+ memory device cannot be hotplugged. This option allows the following
+ two things:
+ - When the system is booting, node full of hotpluggable memory can
+ be arranged to have only movable memory so that the whole node can
+ be hotplugged. (need movable_node boot option specified).
+ - After the system is up, the option allows users to online all the
+ memory of a node as movable memory so that the whole node can be
+ hotplugged.
+
+ Users who don't use the memory hotplug feature are fine with this
+ option on since they don't specify movable_node boot option or they
+ don't online memory as movable.
Say Y here if you want to hotplug a whole node.
Say N here if you want kernel to use memory on all nodes evenly.
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index b468f77..5e2aed9 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1424,7 +1424,7 @@ static bool can_offline_normal(struct zone *zone,
unsigned long nr_pages)
}
#endif /* CONFIG_MOVABLE_NODE */
-static int __init cmdline_parse_movablenode(char *p)
+static int __init cmdline_parse_movable_node(char *p)
{
#ifdef CONFIG_MOVABLE_NODE
/*
@@ -1448,11 +1448,11 @@ static int __init cmdline_parse_movablenode(char *p)
*/
memblock_set_bottom_up(true);
#else
- pr_warn("movablenode option not supported");
+ pr_warn("movable_node option not supported");
#endif
return 0;
}
-early_param("movablenode", cmdline_parse_movablenode);
+early_param("movable_node", cmdline_parse_movable_node);
/* check which state of node_states will be changed when offline memory */
static void node_states_check_changes_offline(unsigned long nr_pages,
--
1.7.1
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[PATCH -mm] mm, memory-hotpulg: Rename movablenode boot option to movable_node
From: Zhang Yanfei zhangyan...@cn.fujitsu.com
Since we already has config MOVABLE_NODE, and the boot option
movablenode is introduced as the boot-time switch to disable
the effects of CONFIG_MOVABLE_NODE=y when the system is booting.
So rename boot option movablenode to movable_node to match the
config MOVABLE_NODE. And also updates the description of MOVABLE_NODE
in mm/Kconfig and the description of movable_node in kernel doc.
Suggested-by: Ingo Molnar mi...@kernel.org
Signed-off-by: Zhang Yanfei zhangyan...@cn.fujitsu.com
---
Documentation/kernel-parameters.txt | 16 ++--
mm/Kconfig | 17 -
mm/memory_hotplug.c |6 +++---
3 files changed, 17 insertions(+), 22 deletions(-)
diff --git a/Documentation/kernel-parameters.txt
b/Documentation/kernel-parameters.txt
index a87e17e..953a533 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1773,20 +1773,8 @@ bytes respectively. Such letter suffixes can also be
entirely omitted.
that the amount of memory usable for all allocations
is not too small.
- movablenode [KNL,X86] This parameter enables/disables the
- kernel to arrange hotpluggable memory ranges recorded
- in ACPI SRAT(System Resource Affinity Table) as
- ZONE_MOVABLE. And these memory can be hot-removed when
- the system is up.
- By specifying this option, all the hotpluggable memory
- will be in ZONE_MOVABLE, which the kernel cannot use.
- This will cause NUMA performance down. For users who
- care about NUMA performance, just don't use it.
- If all the memory ranges in the system are hotpluggable,
- then the ones used by the kernel at early time, such as
- kernel code and data segments, initrd file and so on,
- won't be set as ZONE_MOVABLE, and won't be hotpluggable.
- Otherwise the kernel won't have enough memory to boot.
+ movable_node[KNL,X86] Boot-time switch to disable the effects
+ of CONFIG_MOVABLE_NODE=y. See mm/Kconfig for details.
MTD_Partition= [MTD]
Format: name,region-number,size,offset
diff --git a/mm/Kconfig b/mm/Kconfig
index ff6e820..8d4ebb0 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -153,11 +153,18 @@ config MOVABLE_NODE
help
Allow a node to have only movable memory. Pages used by the kernel,
such as direct mapping pages cannot be migrated. So the corresponding
- memory device cannot be hotplugged. This option allows users to
- online all the memory of a node as movable memory so that the whole
- node can be hotplugged. Users who don't use the memory hotplug
- feature are fine with this option on since they don't online memory
- as movable.
+ memory device cannot be hotplugged. This option allows the following
+ two things:
+ - When the system is booting, node full of hotpluggable memory can
+ be arranged to have only movable memory so that the whole node can
+ be hotplugged. (need movable_node boot option specified).
+ - After the system is up, the option allows users to online all the
+ memory of a node as movable memory so that the whole node can be
+ hotplugged.
+
+ Users who don't use the memory hotplug feature are fine with this
+ option on since they don't specify movable_node boot option or they
+ don't online memory as movable.
Say Y here if you want to hotplug a whole node.
Say N here if you want kernel to use memory on all nodes evenly.
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index b468f77..5e2aed9 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1424,7 +1424,7 @@ static bool can_offline_normal(struct zone *zone,
unsigned long nr_pages)
}
#endif /* CONFIG_MOVABLE_NODE */
-static int __init cmdline_parse_movablenode(char *p)
+static int __init cmdline_parse_movable_node(char *p)
{
#ifdef CONFIG_MOVABLE_NODE
/*
@@ -1448,11 +1448,11 @@ static int __init cmdline_parse_movablenode(char *p)
*/
memblock_set_bottom_up(true);
#else
- pr_warn(movablenode option not supported);
+ pr_warn(movable_node option not supported);
#endif
return 0;
}
-early_param(movablenode, cmdline_parse_movablenode);
+early_param(movable_node, cmdline_parse_movable_node);
/* check which state of node_states will be changed when offline memory */
static void node_states_check_changes_offline(unsigned long nr_pages,
--
1.7.1
--
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Re: [PATCH -mm] mm, memory-hotpulg: Rename movablenode boot option to movable_node
* Zhang Yanfei zhangyanfei@gmail.com wrote: @@ -153,11 +153,18 @@ config MOVABLE_NODE help Allow a node to have only movable memory. Pages used by the kernel, such as direct mapping pages cannot be migrated. So the corresponding + memory device cannot be hotplugged. This option allows the following + two things: + - When the system is booting, node full of hotpluggable memory can + be arranged to have only movable memory so that the whole node can + be hotplugged. (need movable_node boot option specified). So this is _exactly_ what I complained about earlier: why is the movable_node boot option needed to get that extra functionality? It's clearly not just a drop-in substitute to CONFIG_MOVABLE_NODE but extends its functionality, right? Boot options are _very_ poor user interface. If you don't want to enable it by default then turn this sub-functionality into CONFIG_MOVABLE_NODE_AUTO and keep it default-off - but don't pretend that this is only about CONFIG_MOVABLE_NODE alone - it isnt: as described above the 'movable_node' is needed for the full functionality to be available! Thanks, Ingo -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
