linux_dsm_epyc7002/Documentation/ABI/testing
Badari Pulavarty 5c755e9fd8 memory-hotplug: add sysfs removable attribute for hotplug memory remove
Memory may be hot-removed on a per-memory-block basis, particularly on
POWER where the SPARSEMEM section size often matches the memory-block
size.  A user-level agent must be able to identify which sections of
memory are likely to be removable before attempting the potentially
expensive operation.  This patch adds a file called "removable" to the
memory directory in sysfs to help such an agent.  In this patch, a memory
block is considered removable if;

o It contains only MOVABLE pageblocks
o It contains only pageblocks with free pages regardless of pageblock type

On the other hand, a memory block starting with a PageReserved() page will
never be considered removable.  Without this patch, the user-agent is
forced to choose a memory block to remove randomly.

Sample output of the sysfs files:

./memory/memory0/removable: 0
./memory/memory1/removable: 0
./memory/memory2/removable: 0
./memory/memory3/removable: 0
./memory/memory4/removable: 0
./memory/memory5/removable: 0
./memory/memory6/removable: 0
./memory/memory7/removable: 1
./memory/memory8/removable: 0
./memory/memory9/removable: 0
./memory/memory10/removable: 0
./memory/memory11/removable: 0
./memory/memory12/removable: 0
./memory/memory13/removable: 0
./memory/memory14/removable: 0
./memory/memory15/removable: 0
./memory/memory16/removable: 0
./memory/memory17/removable: 1
./memory/memory18/removable: 1
./memory/memory19/removable: 1
./memory/memory20/removable: 1
./memory/memory21/removable: 1
./memory/memory22/removable: 1

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:21 -07:00
..
debugfs-pktcdvd [PATCH] pktcdvd: cleanup 2007-02-11 10:51:28 -08:00
procfs-diskstats Enhanced partition statistics: documentation update 2008-02-08 12:42:11 +01:00
sysfs-block block: Data integrity infrastructure documentation 2008-07-03 13:21:13 +02:00
sysfs-bus-css [S390] cio: Introduce modalias for css bus. 2008-07-14 10:02:05 +02:00
sysfs-bus-pci PCI: Expose PCI VPD through sysfs 2008-04-20 21:47:07 -07:00
sysfs-bus-usb USB: Add documentation for USB suspend statistics. 2008-02-01 14:35:00 -08:00
sysfs-class [PATCH] Add kernel<->userspace ABI stability documentation 2006-06-21 12:40:47 -07:00
sysfs-class-bdi fuse: fix bdi naming conflict 2008-05-24 09:56:07 -07:00
sysfs-class-pktcdvd [PATCH] pktcdvd: cleanup 2007-02-11 10:51:28 -08:00
sysfs-dev sysfs: add /sys/dev/{char,block} to lookup sysfs path by major:minor 2008-07-21 21:54:40 -07:00
sysfs-devices [PATCH] Add kernel<->userspace ABI stability documentation 2006-06-21 12:40:47 -07:00
sysfs-devices-memory memory-hotplug: add sysfs removable attribute for hotplug memory remove 2008-07-24 10:47:21 -07:00
sysfs-firmware-acpi ACPI: Enhance /sys/firmware/interrupts to allow enable/disable/clear from user-space 2008-07-16 23:27:04 +02:00
sysfs-firmware-memmap sysfs: add /sys/firmware/memmap 2008-07-08 17:55:41 +02:00
sysfs-ibft Firmware: add iSCSI iBFT Support 2008-04-19 19:10:28 -07:00
sysfs-kernel-mm mm: create /sys/kernel/mm 2008-07-24 10:47:17 -07:00
sysfs-kernel-mm-hugepages hugetlb: new sysfs interface 2008-07-24 10:47:17 -07:00
sysfs-kernel-uids Documentation: create new scheduler/ subdirectory 2008-02-07 08:42:17 -08:00
sysfs-ocfs2 ocfs2: Document /sys/fs/ocfs2 2008-04-18 08:56:07 -07:00
sysfs-power [PATCH] swsusp: debugging 2006-11-03 12:27:58 -08:00