linux-toradex.git/include/linux/hugetlb.h, branch v4.1.20

mm: hugetlb: cleanup using paeg_huge_active()

2015-04-15T23:35:19+00:00

Now we have an easy access to hugepages' activeness, so existing helpers to
get the information can be cleaned up.

[akpm@linux-foundation.org: s/PageHugeActive/page_huge_active/]
Signed-off-by: Naoya Horiguchi 
Cc: Hugh Dickins 
Reviewed-by: Michal Hocko 
Cc: Mel Gorman 
Cc: Johannes Weiner 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlbfs: accept subpool min_size mount option and setup accordingly

2015-04-15T23:35:18+00:00

Make 'min_size=' be an option when mounting a hugetlbfs.  This
option takes the same value as the 'size' option.  min_size can be
specified without specifying size.  If both are specified, min_size must
be less that or equal to size else the mount will fail.  If min_size is
specified, then at mount time an attempt is made to reserve min_size
pages.  If the reservation fails, the mount fails.  At umount time, the
reserved pages are released.

Signed-off-by: Mike Kravetz 
Cc: Davidlohr Bueso 
Cc: Aneesh Kumar 
Cc: Joonsoo Kim 
Cc: Andi Kleen 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlbfs: add minimum size tracking fields to subpool structure

2015-04-15T23:35:17+00:00

hugetlbfs allocates huge pages from the global pool as needed.  Even if
the global pool contains a sufficient number pages for the filesystem size
at mount time, those global pages could be grabbed for some other use.  As
a result, filesystem huge page allocations may fail due to lack of pages.

Applications such as a database want to use huge pages for performance
reasons.  hugetlbfs filesystem semantics with ownership and modes work
well to manage access to a pool of huge pages.  However, the application
would like some reasonable assurance that allocations will not fail due to
a lack of huge pages.  At application startup time, the application would
like to configure itself to use a specific number of huge pages.  Before
starting, the application can check to make sure that enough huge pages
exist in the system global pools.  However, there are no guarantees that
those pages will be available when needed by the application.  What the
application wants is exclusive use of a subset of huge pages.

Add a new hugetlbfs mount option 'min_size=' to indicate that the
specified number of pages will be available for use by the filesystem.  At
mount time, this number of huge pages will be reserved for exclusive use
of the filesystem.  If there is not a sufficient number of free pages, the
mount will fail.  As pages are allocated to and freeed from the
filesystem, the number of reserved pages is adjusted so that the specified
minimum is maintained.

This patch (of 4):

Add a field to the subpool structure to indicate the minimimum number of
huge pages to always be used by this subpool.  This minimum count includes
allocated pages as well as reserved pages.  If the minimum number of pages
for the subpool have not been allocated, pages are reserved up to this
minimum.  An additional field (rsv_hpages) is used to track the number of
pages reserved to meet this minimum size.  The hstate pointer in the
subpool is convenient to have when reserving and unreserving the pages.

Signed-off-by: Mike Kravetz 
Cc: Davidlohr Bueso 
Cc: Aneesh Kumar 
Cc: Joonsoo Kim 
Cc: Andi Kleen 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: consolidate all page-flags helpers in

2015-04-15T23:35:17+00:00

Currently we take a naive approach to page flags on compound pages - we
set the flag on the page without consideration if the flag makes sense
for tail page or for compound page in general.  This patchset try to
sort this out by defining per-flag policy on what need to be done if
page-flag helper operate on compound page.

The last patch in the patchset also sanitizes usege of page->mapping for
tail pages.  We don't define the meaning of page->mapping for tail
pages.  Currently it's always NULL, which can be inconsistent with head
page and potentially lead to problems.

For now I caught one case of illegal usage of page flags or ->mapping:
sound subsystem allocates pages with __GFP_COMP and maps them with PTEs.
It leads to setting dirty bit on tail pages and access to tail_page's
->mapping.  I don't see any bad behaviour caused by this, but worth
fixing anyway.

This patchset makes more sense if you take my THP refcounting into
account: we will see more compound pages mapped with PTEs and we need to
define behaviour of flags on compound pages to avoid bugs.

This patch (of 16):

We have page-flags helper function declarations/definitions spread over
several header files.  Let's consolidate them in .

Signed-off-by: Kirill A. Shutemov 
Cc: Andrea Arcangeli 
Acked-by: Hugh Dickins 
Cc: Dave Hansen 
Cc: Mel Gorman 
Cc: Rik van Riel 
Cc: Vlastimil Babka 
Cc: Christoph Lameter 
Cc: Naoya Horiguchi 
Cc: Steve Capper 
Cc: "Aneesh Kumar K.V" 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Jerome Marchand 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/hugetlb: take page table lock in follow_huge_pmd()

2015-02-12T01:06:01+00:00

We have a race condition between move_pages() and freeing hugepages, where
move_pages() calls follow_page(FOLL_GET) for hugepages internally and
tries to get its refcount without preventing concurrent freeing.  This
race crashes the kernel, so this patch fixes it by moving FOLL_GET code
for hugepages into follow_huge_pmd() with taking the page table lock.

This patch intentionally removes page==NULL check after pte_page.
This is justified because pte_page() never returns NULL for any
architectures or configurations.

This patch changes the behavior of follow_huge_pmd() for tail pages and
then tail pages can be pinned/returned.  So the caller must be changed to
properly handle the returned tail pages.

We could have a choice to add the similar locking to
follow_huge_(addr|pud) for consistency, but it's not necessary because
currently these functions don't support FOLL_GET flag, so let's leave it
for future development.

Here is the reproducer:

  $ cat movepages.c
  #include 
  #include 
  #include 

  #define ADDR_INPUT      0x700000000000UL
  #define HPS             0x200000
  #define PS              0x1000

  int main(int argc, char *argv[]) {
          int i;
          int nr_hp = strtol(argv[1], NULL, 0);
          int nr_p  = nr_hp * HPS / PS;
          int ret;
          void **addrs;
          int *status;
          int *nodes;
          pid_t pid;

          pid = strtol(argv[2], NULL, 0);
          addrs  = malloc(sizeof(char *) * nr_p + 1);
          status = malloc(sizeof(char *) * nr_p + 1);
          nodes  = malloc(sizeof(char *) * nr_p + 1);

          while (1) {
                  for (i = 0; i < nr_p; i++) {
                          addrs[i] = (void *)ADDR_INPUT + i * PS;
                          nodes[i] = 1;
                          status[i] = 0;
                  }
                  ret = numa_move_pages(pid, nr_p, addrs, nodes, status,
                                        MPOL_MF_MOVE_ALL);
                  if (ret == -1)
                          err("move_pages");

                  for (i = 0; i < nr_p; i++) {
                          addrs[i] = (void *)ADDR_INPUT + i * PS;
                          nodes[i] = 0;
                          status[i] = 0;
                  }
                  ret = numa_move_pages(pid, nr_p, addrs, nodes, status,
                                        MPOL_MF_MOVE_ALL);
                  if (ret == -1)
                          err("move_pages");
          }
          return 0;
  }

  $ cat hugepage.c
  #include 
  #include 
  #include 

  #define ADDR_INPUT      0x700000000000UL
  #define HPS             0x200000

  int main(int argc, char *argv[]) {
          int nr_hp = strtol(argv[1], NULL, 0);
          char *p;

          while (1) {
                  p = mmap((void *)ADDR_INPUT, nr_hp * HPS, PROT_READ | PROT_WRITE,
                           MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
                  if (p != (void *)ADDR_INPUT) {
                          perror("mmap");
                          break;
                  }
                  memset(p, 0, nr_hp * HPS);
                  munmap(p, nr_hp * HPS);
          }
  }

  $ sysctl vm.nr_hugepages=40
  $ ./hugepage 10 &
  $ ./movepages 10 $(pgrep -f hugepage)

Fixes: e632a938d914 ("mm: migrate: add hugepage migration code to move_pages()")
Signed-off-by: Naoya Horiguchi 
Reported-by: Hugh Dickins 
Cc: James Hogan 
Cc: David Rientjes 
Cc: Mel Gorman 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Rik van Riel 
Cc: Andrea Arcangeli 
Cc: Luiz Capitulino 
Cc: Nishanth Aravamudan 
Cc: Lee Schermerhorn 
Cc: Steve Capper 
Cc: 	[3.12+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: hugetlb: fix type of hugetlb_treat_as_movable variable

2015-02-10T22:30:34+00:00

hugetlb_treat_as_movable declared as unsigned long, but
proc_dointvec() used for parsing it:

static struct ctl_table vm_table[] = {
...
        {
                .procname	= "hugepages_treat_as_movable",
                .data		= &hugepages_treat_as_movable,
                .maxlen		= sizeof(int),
                .mode		= 0644,
                .proc_handler	= proc_dointvec,
        },

This seems harmless, but it's better to use int type here.

Signed-off-by: Andrey Ryabinin 
Cc: Dmitry Vyukov 
Cc: Manfred Spraul 
Acked-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'powerpc-3.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux

2014-12-12T01:48:14+00:00

Pull powerpc updates from Michael Ellerman:
"Some nice cleanups like removing bootmem, and removal of
__get_cpu_var().

There is one patch to mm/gup.c. This is the generic GUP
implementation, but is only used by us and arm(64). We have an ack
from Steve Capper, and although we didn't get an ack from Andrew he
told us to take the patch through the powerpc tree.

There's one cxl patch. This is in drivers/misc, but Greg said he was
happy for us to manage fixes for it.

There is an infrastructure patch to support an IPMI driver for OPAL.

There is also an RTC driver for OPAL. We weren't able to get any
response from the RTC maintainer, Alessandro Zummo, so in the end we
just merged the driver.

The usual batch of Freescale updates from Scott"

* tag 'powerpc-3.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (101 commits)
powerpc/powernv: Return to cpu offline loop when finished in KVM guest
powerpc/book3s: Fix partial invalidation of TLBs in MCE code.
powerpc/mm: don't do tlbie for updatepp request with NO HPTE fault
powerpc/xmon: Cleanup the breakpoint flags
powerpc/xmon: Enable HW instruction breakpoint on POWER8
powerpc/mm/thp: Use tlbiel if possible
powerpc/mm/thp: Remove code duplication
powerpc/mm/hugetlb: Sanity check gigantic hugepage count
powerpc/oprofile: Disable pagefaults during user stack read
powerpc/mm: Check for matching hpte without taking hpte lock
powerpc: Drop useless warning in eeh_init()
powerpc/powernv: Cleanup unused MCE definitions/declarations.
powerpc/eeh: Dump PHB diag-data early
powerpc/eeh: Recover EEH error on ownership change for BCM5719
powerpc/eeh: Set EEH_PE_RESET on PE reset
powerpc/eeh: Refactor eeh_reset_pe()
powerpc: Remove more traces of bootmem
powerpc/pseries: Initialise nvram_pstore_info's buf_lock
cxl: Name interrupts in /proc/interrupt
cxl: Return error to PSL if IRQ demultiplexing fails & print clearer warning
...

mm, hugetlb: correct bit shift in hstate_sizelog()

2014-12-11T01:41:07+00:00

hstate_sizelog() would shift left an int rather than long, triggering
undefined behaviour and passing an incorrect value when the requested
page size was more than 4GB, thus breaking >4GB pages.

Signed-off-by: Sasha Levin 
Cc: Andrea Arcangeli 
Cc: Mel Gorman 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: Update generic gup implementation to handle hugepage directory

2014-11-14T06:24:21+00:00

Update generic gup implementation with powerpc specific details.
On powerpc at pmd level we can have hugepte, normal pmd pointer
or a pointer to the hugepage directory.

Tested-by: Steve Capper 
Acked-by: Steve Capper 
Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman

mm, hugetlb: remove hugetlb_zero and hugetlb_infinity

2014-08-07T01:01:19+00:00

They are unnecessary: "zero" can be used in place of "hugetlb_zero" and
passing extra2 == NULL is equivalent to infinity.

Signed-off-by: David Rientjes 
Cc: Joonsoo Kim 
Reviewed-by: Naoya Horiguchi 
Reviewed-by: Luiz Capitulino 
Cc: "Kirill A. Shutemov" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds