Re: [PATCH 9/9] v3 Update memory hotplug documentation
On Fri, 01 Oct 2010 13:37:49 -0500 Nathan Fontenot nf...@austin.ibm.com wrote: Update the memory hotplug documentation to reflect the new behaviors of memory blocks reflected in sysfs. Signed-off-by: Nathan Fontenot nf...@austin.ibm.com Reviewed-by: KAMEZAWA Hiroyuki kamezawa.hir...@jp.fujitsu.com Thank you for your patient work!. --- Documentation/memory-hotplug.txt | 47 +-- 1 file changed, 31 insertions(+), 16 deletions(-) Index: linux-next/Documentation/memory-hotplug.txt === --- linux-next.orig/Documentation/memory-hotplug.txt 2010-09-29 14:56:24.0 -0500 +++ linux-next/Documentation/memory-hotplug.txt 2010-09-30 14:59:47.0 -0500 @@ -126,36 +126,51 @@ 4 sysfs files for memory hotplug -All sections have their device information under /sys/devices/system/memory as +All sections have their device information in sysfs. Each section is part of +a memory block under /sys/devices/system/memory as /sys/devices/system/memory/memoryXXX -(XXX is section id.) +(XXX is the section id.) -Now, XXX is defined as start_address_of_section / section_size. +Now, XXX is defined as (start_address_of_section / section_size) of the first +section contained in the memory block. The files 'phys_index' and +'end_phys_index' under each directory report the beginning and end section id's +for the memory block covered by the sysfs directory. It is expected that all +memory sections in this range are present and no memory holes exist in the +range. Currently there is no way to determine if there is a memory hole, but +the existence of one should not affect the hotplug capabilities of the memory +block. For example, assume 1GiB section size. A device for a memory starting at 0x1 is /sys/device/system/memory/memory4 (0x1 / 1Gib = 4) This device covers address range [0x1 ... 0x14000) -Under each section, you can see 4 files. +Under each section, you can see 4 or 5 files, the end_phys_index file being +a recent addition and not present on older kernels. -/sys/devices/system/memory/memoryXXX/phys_index +/sys/devices/system/memory/memoryXXX/start_phys_index +/sys/devices/system/memory/memoryXXX/end_phys_index /sys/devices/system/memory/memoryXXX/phys_device /sys/devices/system/memory/memoryXXX/state /sys/devices/system/memory/memoryXXX/removable -'phys_index' : read-only and contains section id, same as XXX. -'state' : read-write - at read: contains online/offline state of memory. - at write: user can specify online, offline command -'phys_device': read-only: designed to show the name of physical memory device. - This is not well implemented now. -'removable' : read-only: contains an integer value indicating - whether the memory section is removable or not - removable. A value of 1 indicates that the memory - section is removable and a value of 0 indicates that - it is not removable. +'phys_index' : read-only and contains section id of the first section + in the memory block, same as XXX. +'end_phys_index' : read-only and contains section id of the last section + in the memory block. +'state' : read-write +at read: contains online/offline state of memory. +at write: user can specify online, offline command +which will be performed on al sections in the block. +'phys_device' : read-only: designed to show the name of physical memory +device. This is not well implemented now. +'removable' : read-only: contains an integer value indicating +whether the memory block is removable or not +removable. A value of 1 indicates that the memory +block is removable and a value of 0 indicates that +it is not removable. A memory block is removable only if +every section in the block is removable. NOTE: These directories/files appear after physical memory hotplug phase. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
[PATCH 9/9] v3 Update memory hotplug documentation
Update the memory hotplug documentation to reflect the new behaviors of memory blocks reflected in sysfs. Signed-off-by: Nathan Fontenot nf...@austin.ibm.com --- Documentation/memory-hotplug.txt | 47 +-- 1 file changed, 31 insertions(+), 16 deletions(-) Index: linux-next/Documentation/memory-hotplug.txt === --- linux-next.orig/Documentation/memory-hotplug.txt2010-09-29 14:56:24.0 -0500 +++ linux-next/Documentation/memory-hotplug.txt 2010-09-30 14:59:47.0 -0500 @@ -126,36 +126,51 @@ 4 sysfs files for memory hotplug -All sections have their device information under /sys/devices/system/memory as +All sections have their device information in sysfs. Each section is part of +a memory block under /sys/devices/system/memory as /sys/devices/system/memory/memoryXXX -(XXX is section id.) +(XXX is the section id.) -Now, XXX is defined as start_address_of_section / section_size. +Now, XXX is defined as (start_address_of_section / section_size) of the first +section contained in the memory block. The files 'phys_index' and +'end_phys_index' under each directory report the beginning and end section id's +for the memory block covered by the sysfs directory. It is expected that all +memory sections in this range are present and no memory holes exist in the +range. Currently there is no way to determine if there is a memory hole, but +the existence of one should not affect the hotplug capabilities of the memory +block. For example, assume 1GiB section size. A device for a memory starting at 0x1 is /sys/device/system/memory/memory4 (0x1 / 1Gib = 4) This device covers address range [0x1 ... 0x14000) -Under each section, you can see 4 files. +Under each section, you can see 4 or 5 files, the end_phys_index file being +a recent addition and not present on older kernels. -/sys/devices/system/memory/memoryXXX/phys_index +/sys/devices/system/memory/memoryXXX/start_phys_index +/sys/devices/system/memory/memoryXXX/end_phys_index /sys/devices/system/memory/memoryXXX/phys_device /sys/devices/system/memory/memoryXXX/state /sys/devices/system/memory/memoryXXX/removable -'phys_index' : read-only and contains section id, same as XXX. -'state' : read-write - at read: contains online/offline state of memory. - at write: user can specify online, offline command -'phys_device': read-only: designed to show the name of physical memory device. - This is not well implemented now. -'removable' : read-only: contains an integer value indicating - whether the memory section is removable or not - removable. A value of 1 indicates that the memory - section is removable and a value of 0 indicates that - it is not removable. +'phys_index' : read-only and contains section id of the first section + in the memory block, same as XXX. +'end_phys_index' : read-only and contains section id of the last section + in the memory block. +'state' : read-write +at read: contains online/offline state of memory. +at write: user can specify online, offline command +which will be performed on al sections in the block. +'phys_device' : read-only: designed to show the name of physical memory +device. This is not well implemented now. +'removable' : read-only: contains an integer value indicating +whether the memory block is removable or not +removable. A value of 1 indicates that the memory +block is removable and a value of 0 indicates that +it is not removable. A memory block is removable only if +every section in the block is removable. NOTE: These directories/files appear after physical memory hotplug phase. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 9/9] v3 Update memory hotplug documentation
On Fri, Oct 01, 2010 at 01:37:49PM -0500, Nathan Fontenot wrote: Update the memory hotplug documentation to reflect the new behaviors of memory blocks reflected in sysfs. Signed-off-by: Nathan Fontenot nf...@austin.ibm.com Reviewed-by: Robin Holt h...@sgi.com ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
