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authorNishanth Aravamudan <nacc@us.ibm.com>2008-07-23 21:27:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 10:47:17 -0700
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hugetlb: new sysfs interface
Provide new hugepages user APIs that are more suited to multiple hstates in sysfs. There is a new directory, /sys/kernel/hugepages. Underneath that directory there will be a directory per-supported hugepage size, e.g.: /sys/kernel/hugepages/hugepages-64kB /sys/kernel/hugepages/hugepages-16384kB /sys/kernel/hugepages/hugepages-16777216kB corresponding to 64k, 16m and 16g respectively. Within each hugepages-size directory there are a number of files, corresponding to the tracked counters in the hstate, e.g.: /sys/kernel/hugepages/hugepages-64/nr_hugepages /sys/kernel/hugepages/hugepages-64/nr_overcommit_hugepages /sys/kernel/hugepages/hugepages-64/free_hugepages /sys/kernel/hugepages/hugepages-64/resv_hugepages /sys/kernel/hugepages/hugepages-64/surplus_hugepages Of these files, the first two are read-write and the latter three are read-only. The size of the hugepage being manipulated is trivially deducible from the enclosing directory and is always expressed in kB (to match meminfo). [dave@linux.vnet.ibm.com: fix build] [nacc@us.ibm.com: hugetlb: hang off of /sys/kernel/mm rather than /sys/kernel] [nacc@us.ibm.com: hugetlb: remove CONFIG_SYSFS dependency] Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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+What: /sys/kernel/mm/hugepages/
+Date: June 2008
+Contact: Nishanth Aravamudan <nacc@us.ibm.com>, hugetlb maintainers
+Description:
+ /sys/kernel/mm/hugepages/ contains a number of subdirectories
+ of the form hugepages-<size>kB, where <size> is the page size
+ of the hugepages supported by the kernel/CPU combination.
+
+ Under these directories are a number of files:
+ nr_hugepages
+ nr_overcommit_hugepages
+ free_hugepages
+ surplus_hugepages
+ resv_hugepages
+ See Documentation/vm/hugetlbpage.txt for details.