kernel_samsung_sm7125

jenna

History

Andy Whitcroft cdfd4325c0 mm: record MAP_NORESERVE status on vmas and fix small page mprotect reservations With Mel's hugetlb private reservation support patches applied, strict overcommit semantics are applied to both shared and private huge page mappings. This can be a problem if an application relied on unlimited overcommit semantics for private mappings. An example of this would be an application which maps a huge area with the intention of using it very sparsely. These application would benefit from being able to opt-out of the strict overcommit. It should be noted that prior to hugetlb supporting demand faulting all mappings were fully populated and so applications of this type should be rare. This patch stack implements the MAP_NORESERVE mmap() flag for huge page mappings. This flag has the same meaning as for small page mappings, suppressing reservations for that mapping. Thanks to Mel Gorman for reviewing a number of early versions of these patches. This patch: When a small page mapping is created with mmap() reservations are created by default for any memory pages required. When the region is read/write the reservation is increased for every page, no reservation is needed for read-only regions (as they implicitly share the zero page). Reservations are tracked via the VM_ACCOUNT vma flag which is present when the region has reservation backing it. When we convert a region from read-only to read-write new reservations are aquired and VM_ACCOUNT is set. However, when a read-only map is created with MAP_NORESERVE it is indistinguishable from a normal mapping. When we then convert that to read/write we are forced to incorrectly create reservations for it as we have no record of the original MAP_NORESERVE. This patch introduces a new vma flag VM_NORESERVE which records the presence of the original MAP_NORESERVE flag. This allows us to distinguish these two circumstances and correctly account the reserve. As well as fixing this FIXME in the code, this makes it much easier to introduce MAP_NORESERVE support for huge pages as this flag is available consistantly for the life of the mapping. VM_ACCOUNT on the other hand is heavily used at the generic level in association with small pages. Signed-off-by: Andy Whitcroft <apw@shadowen.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Adam Litke <agl@us.ibm.com> Cc: Johannes Weiner <hannes@saeurebad.de> Cc: Andy Whitcroft <apw@shadowen.org> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		17 years ago
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Kconfig	Merge git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6	17 years ago
Makefile	mm: add a basic debugging framework for memory initialisation	17 years ago
allocpercpu.c	Merge commit 'v2.6.26-rc9' into cpus4096	17 years ago
backing-dev.c	mm: bdi: fix race in bdi_class device creation	17 years ago
bootmem.c	mm: unexport __alloc_bootmem_core()	17 years ago
bounce.c	…
dmapool.c	dmapool: enable debugging for CONFIG_SLUB_DEBUG_ON too	17 years ago
fadvise.c	xip: support non-struct page backed memory	17 years ago
filemap.c	kill generic_file_direct_IO()	17 years ago
filemap_xip.c	xip: support non-struct page backed memory	17 years ago
fremap.c	mm: fix various kernel-doc comments	17 years ago
highmem.c	highmem: Export totalhigh_pages.	17 years ago
hugetlb.c	huge page private reservation review cleanups	17 years ago
internal.h	mm: remove double indirection on tlb parameter to free_pgd_range() & Co	17 years ago
maccess.c	kgdb: fix optional arch functions and probe_kernel_*	17 years ago
madvise.c	xip: support non-struct page backed memory	17 years ago
memcontrol.c	memcg: simple stats for memory resource controller	17 years ago
memory.c	hugetlb: guarantee that COW faults for a process that called mmap(MAP_PRIVATE) on hugetlbfs will succeed	17 years ago
memory_hotplug.c	mm: drop unneeded pgdat argument from free_area_init_node()	17 years ago
mempolicy.c	mempolicy: mask off internal flags for userspace API	17 years ago
mempool.c	spelling fixes: mm/	18 years ago
migrate.c	mm/migrate.c should #include <linux/syscalls.h>	17 years ago
mincore.c	mm: remove nopage	17 years ago
mlock.c	…
mm_init.c	mm: print out the zonelists on request for manual verification	17 years ago
mmap.c	mm: record MAP_NORESERVE status on vmas and fix small page mprotect reservations	17 years ago
mmzone.c	mm: filter based on a nodemask as well as a gfp_mask	17 years ago
mprotect.c	mm: record MAP_NORESERVE status on vmas and fix small page mprotect reservations	17 years ago
mremap.c	…
msync.c	…
nommu.c	nommu: Correct kobjsize() page validity checks.	17 years ago
oom_kill.c	oom_kill: remove unused parameter in badness()	17 years ago
page-writeback.c	Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4	17 years ago
page_alloc.c	mm: drop unneeded pgdat argument from free_area_init_node()	17 years ago
page_io.c	mm: fix PageUptodate data race	17 years ago
page_isolation.c	memory hotremove: unset migrate type "ISOLATE" after removal	17 years ago
pagewalk.c	pagemap: pass mm into pagewalkers	17 years ago
pdflush.c	mm/pdflush.c: merge the same code in two path	17 years ago
prio_tree.c	spelling fixes: mm/	18 years ago
quicklist.c	quicklists: Only consider memory that can be used with GFP_KERNEL	17 years ago
readahead.c	mm: bdi: export BDI attributes in sysfs	17 years ago
rmap.c	mm: remove nopage	17 years ago
shmem.c	mm: bdi: add separate writeback accounting capability	17 years ago
shmem_acl.c	…
slab.c	Merge branch 'generic-ipi' into generic-ipi-for-linus	17 years ago
slob.c	slob: record page flag overlays explicitly	17 years ago
slub.c	slub: record page flag overlays explicitly	17 years ago
sparse-vmemmap.c	Christoph has moved	17 years ago
sparse.c	mm: make defensive checks around PFN values registered for memory usage	17 years ago
swap.c	mm: fix atomic_t overflow in vm	17 years ago
swap_state.c	mm: bdi: add separate writeback accounting capability	17 years ago
swapfile.c	mm: use non-racy method for /proc/swaps creation	17 years ago
thrash.c	…
tiny-shmem.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6	17 years ago
truncate.c	fix invalidate_inode_pages2_range() to not clear ret	17 years ago
util.c	fix mm/util.c:krealloc()	17 years ago
vmalloc.c	docbook: fix vmalloc missing parameter notation	17 years ago
vmscan.c	mm: fix incorrect variable type in do_try_to_free_pages()	17 years ago
vmstat.c	mm/vmstat.c: proper externs	17 years ago