linux-toradex.git/include/linux/hugetlb.h, branch v2.6.29

hugetlbfs: fix build failure with !CONFIG_HUGETLBFS

2009-02-10T22:56:59+00:00

Fix regression due to 5a6fe125950676015f5108fb71b2a67441755003,
"Do not account for the address space used by hugetlbfs using VM_ACCOUNT"
which added an argument to the function hugetlb_file_setup() but not to
the macro hugetlb_file_setup().

Reported-by: Chris Clayton 
Signed-off-by: Stefan Richter 
Acked-by: Mel Gorman 
Signed-off-by: Linus Torvalds

Do not account for the address space used by hugetlbfs using VM_ACCOUNT

2009-02-10T18:48:42+00:00

When overcommit is disabled, the core VM accounts for pages used by anonymous
shared, private mappings and special mappings. It keeps track of VMAs that
should be accounted for with VM_ACCOUNT and VMAs that never had a reserve
with VM_NORESERVE.

Overcommit for hugetlbfs is much riskier than overcommit for base pages
due to contiguity requirements. It avoids overcommiting on both shared and
private mappings using reservation counters that are checked and updated
during mmap(). This ensures (within limits) that hugepages exist in the
future when faults occurs or it is too easy to applications to be SIGKILLed.

As hugetlbfs makes its own reservations of a different unit to the base page
size, VM_ACCOUNT should never be set. Even if the units were correct, we would
double account for the usage in the core VM and hugetlbfs. VM_NORESERVE may
be set because an application can request no reserves be made for hugetlbfs
at the risk of getting killed later.

With commit fc8744adc870a8d4366908221508bb113d8b72ee, VM_NORESERVE and
VM_ACCOUNT are getting unconditionally set for hugetlbfs-backed mappings. This
breaks the accounting for both the core VM and hugetlbfs, can trigger an
OOM storm when hugepage pools are too small lockups and corrupted counters
otherwise are used. This patch brings hugetlbfs more in line with how the
core VM treats VM_NORESERVE but prevents VM_ACCOUNT being set.

Signed-off-by: Mel Gorman 
Signed-off-by: Linus Torvalds

mm: report the MMU pagesize in /proc/pid/smaps

2009-01-06T23:58:58+00:00

The KernelPageSize entry in /proc/pid/smaps is the pagesize used by the
kernel to back a VMA.  This matches the size used by the MMU in the
majority of cases.  However, one counter-example occurs on PPC64 kernels
whereby a kernel using 64K as a base pagesize may still use 4K pages for
the MMU on older processor.  To distinguish, this patch reports
MMUPageSize as the pagesize used by the MMU in /proc/pid/smaps.

Signed-off-by: Mel Gorman 
Cc: "KOSAKI Motohiro" 
Cc: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: report the pagesize backing a VMA in /proc/pid/smaps

2009-01-06T23:58:58+00:00

It is useful to verify a hugepage-aware application is using the expected
pagesizes for its memory regions. This patch creates an entry called
KernelPageSize in /proc/pid/smaps that is the size of page used by the
kernel to back a VMA. The entry is not called PageSize as it is possible
the MMU uses a different size. This extension should not break any sensible
parser that skips lines containing unrecognised information.

Signed-off-by: Mel Gorman 
Acked-by: "KOSAKI Motohiro" 
Cc: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc: switch /proc/meminfo to seq_file

2008-10-23T09:52:40+00:00

and move it to fs/proc/meminfo.c while I'm at it.

Signed-off-by: Alexey Dobriyan

hugetlb: remove unused variable warning

2008-07-27T03:16:47+00:00

Remove the following warning when CONFIG_HUGETLB_PAGE is not set:

	ipc/shm.c: In function `shm_get_stat':
	ipc/shm.c:565: warning: unused variable `h'

[akpm@linux-foundation.org: use tabs, not spaces]
Signed-off-by: Andrea Righi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlb: allow arch overridden hugepage allocation

2008-07-24T17:47:19+00:00

Allow alloc_bootmem_huge_page() to be overridden by architectures that
can't always use bootmem.  This requires huge_boot_pages to be available
for use by this function.

This is required for powerpc 16G pages, which have to be reserved prior to
boot-time.  The location of these pages are indicated in the device tree.

Acked-by: Adam Litke 
Signed-off-by: Jon Tollefson 
Signed-off-by: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlb: introduce pud_huge

2008-07-24T17:47:18+00:00

Straight forward extensions for huge pages located in the PUD instead of
PMDs.

Signed-off-by: Andi Kleen 
Signed-off-by: Nick Piggin 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlb: new sysfs interface

2008-07-24T17:47:17+00:00

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 
Signed-off-by: Nishanth Aravamudan 
Signed-off-by: Nick Piggin 
Cc: Dave Hansen 
Signed-off-by: Nishanth Aravamudan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlbfs: per mount huge page sizes

2008-07-24T17:47:17+00:00

Add the ability to configure the hugetlb hstate used on a per mount basis.

- Add a new pagesize= option to the hugetlbfs mount that allows setting
  the page size
- This option causes the mount code to find the hstate corresponding to the
  specified size, and sets up a pointer to the hstate in the mount's
  superblock.
- Change the hstate accessors to use this information rather than the
  global_hstate they were using (requires a slight change in mm/memory.c
  so we don't NULL deref in the error-unmap path -- see comments).

[np: take hstate out of hugetlbfs inode and vma->vm_private_data]

Acked-by: Adam Litke 
Acked-by: Nishanth Aravamudan 
Signed-off-by: Andi Kleen 
Signed-off-by: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds