1. 31 May, 2016 1 commit
  2. 19 May, 2016 1 commit
  3. 17 Mar, 2016 1 commit
  4. 09 Mar, 2016 1 commit
    • Will Deacon's avatar
      arm64: hugetlb: partial revert of 66b3923a · ff792584
      Will Deacon authored
      Commit 66b3923a ("arm64: hugetlb: add support for PTE contiguous bit")
      introduced support for huge pages using the contiguous bit in the PTE
      as opposed to block mappings, which may be slightly unwieldy (512M) in
      64k page configurations.
      
      Unfortunately, this support has resulted in some late regressions when
      running the libhugetlbfs test suite with 64k pages and CONFIG_DEBUG_VM
      as a result of a BUG:
      
       | readback (2M: 64):	------------[ cut here ]------------
       | kernel BUG at fs/hugetlbfs/inode.c:446!
       | Internal error: Oops - BUG: 0 [#1] SMP
       | Modules linked in:
       | CPU: 7 PID: 1448 Comm: readback Not tainted 4.5.0-rc7 #148
       | Hardware name: linux,dummy-virt (DT)
       | task: fffffe0040964b00 ti: fffffe00c2668000 task.ti: fffffe00c2668000
       | PC is at remove_inode_hugepages+0x44c/0x480
       | LR is at remove_inode_hugepages+0x264/0x480
      
      Rather than revert the entire patch, simply avoid advertising the
      contiguous huge page sizes for now while people are actively working on
      a fix. This patch can then be reverted once things have been sorted out.
      
      Cc: David Woods <dwoods@ezchip.com>
      Reported-by: default avatarSteve Capper <steve.capper@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      ff792584
  5. 21 Dec, 2015 1 commit
    • David Woods's avatar
      arm64: hugetlb: add support for PTE contiguous bit · 66b3923a
      David Woods authored
      The arm64 MMU supports a Contiguous bit which is a hint that the TTE
      is one of a set of contiguous entries which can be cached in a single
      TLB entry.  Supporting this bit adds new intermediate huge page sizes.
      
      The set of huge page sizes available depends on the base page size.
      Without using contiguous pages the huge page sizes are as follows.
      
       4KB:   2MB  1GB
      64KB: 512MB
      
      With a 4KB granule, the contiguous bit groups together sets of 16 pages
      and with a 64KB granule it groups sets of 32 pages.  This enables two new
      huge page sizes in each case, so that the full set of available sizes
      is as follows.
      
       4KB:  64KB   2MB  32MB  1GB
      64KB:   2MB 512MB  16GB
      
      If a 16KB granule is used then the contiguous bit groups 128 pages
      at the PTE level and 32 pages at the PMD level.
      
      If the base page size is set to 64KB then 2MB pages are enabled by
      default.  It is possible in the future to make 2MB the default huge
      page size for both 4KB and 64KB granules.
      Reviewed-by: default avatarChris Metcalf <cmetcalf@ezchip.com>
      Reviewed-by: default avatarSteve Capper <steve.capper@linaro.org>
      Signed-off-by: default avatarDavid Woods <dwoods@ezchip.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      66b3923a
  6. 27 Jul, 2015 1 commit
  7. 01 Jul, 2015 1 commit
  8. 24 Jun, 2015 1 commit
    • Zhang Zhen's avatar
      mm/hugetlb: reduce arch dependent code about huge_pmd_unshare · e81f2d22
      Zhang Zhen authored
      Currently we have many duplicates in definitions of huge_pmd_unshare.  In
      all architectures this function just returns 0 when
      CONFIG_ARCH_WANT_HUGE_PMD_SHARE is N.
      
      This patch puts the default implementation in mm/hugetlb.c and lets these
      architectures use the common code.
      Signed-off-by: default avatarZhang Zhen <zhenzhang.zhang@huawei.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: James Yang <James.Yang@freescale.com>
      Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e81f2d22
  9. 11 Feb, 2015 1 commit
    • Naoya Horiguchi's avatar
      mm/hugetlb: reduce arch dependent code around follow_huge_* · 61f77eda
      Naoya Horiguchi authored
      Currently we have many duplicates in definitions around
      follow_huge_addr(), follow_huge_pmd(), and follow_huge_pud(), so this
      patch tries to remove the m.  The basic idea is to put the default
      implementation for these functions in mm/hugetlb.c as weak symbols
      (regardless of CONFIG_ARCH_WANT_GENERAL_HUGETL B), and to implement
      arch-specific code only when the arch needs it.
      
      For follow_huge_addr(), only powerpc and ia64 have their own
      implementation, and in all other architectures this function just returns
      ERR_PTR(-EINVAL).  So this patch sets returning ERR_PTR(-EINVAL) as
      default.
      
      As for follow_huge_(pmd|pud)(), if (pmd|pud)_huge() is implemented to
      always return 0 in your architecture (like in ia64 or sparc,) it's never
      called (the callsite is optimized away) no matter how implemented it is.
      So in such architectures, we don't need arch-specific implementation.
      
      In some architecture (like mips, s390 and tile,) their current
      arch-specific follow_huge_(pmd|pud)() are effectively identical with the
      common code, so this patch lets these architecture use the common code.
      
      One exception is metag, where pmd_huge() could return non-zero but it
      expects follow_huge_pmd() to always return NULL.  This means that we need
      arch-specific implementation which returns NULL.  This behavior looks
      strange to me (because non-zero pmd_huge() implies that the architecture
      supports PMD-based hugepage, so follow_huge_pmd() can/should return some
      relevant value,) but that's beyond this cleanup patch, so let's keep it.
      
      Justification of non-trivial changes:
      - in s390, follow_huge_pmd() checks !MACHINE_HAS_HPAGE at first, and this
        patch removes the check. This is OK because we can assume MACHINE_HAS_HPAGE
        is true when follow_huge_pmd() can be called (note that pmd_huge() has
        the same check and always returns 0 for !MACHINE_HAS_HPAGE.)
      - in s390 and mips, we use HPAGE_MASK instead of PMD_MASK as done in common
        code. This patch forces these archs use PMD_MASK, but it's OK because
        they are identical in both archs.
        In s390, both of HPAGE_SHIFT and PMD_SHIFT are 20.
        In mips, HPAGE_SHIFT is defined as (PAGE_SHIFT + PAGE_SHIFT - 3) and
        PMD_SHIFT is define as (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3), but
        PTE_ORDER is always 0, so these are identical.
      Signed-off-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Acked-by: default avatarHugh Dickins <hughd@google.com>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Luiz Capitulino <lcapitulino@redhat.com>
      Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
      Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
      Cc: Steve Capper <steve.capper@linaro.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      61f77eda
  10. 04 Jun, 2014 1 commit
  11. 16 May, 2014 1 commit
    • Mark Salter's avatar
      arm64: fix pud_huge() for 2-level pagetables · 4797ec2d
      Mark Salter authored
      The following happens when trying to run a kvm guest on a kernel
      configured for 64k pages. This doesn't happen with 4k pages:
      
        BUG: failure at include/linux/mm.h:297/put_page_testzero()!
        Kernel panic - not syncing: BUG!
        CPU: 2 PID: 4228 Comm: qemu-system-aar Tainted: GF            3.13.0-0.rc7.31.sa2.k32v1.aarch64.debug #1
        Call trace:
        [<fffffe0000096034>] dump_backtrace+0x0/0x16c
        [<fffffe00000961b4>] show_stack+0x14/0x1c
        [<fffffe000066e648>] dump_stack+0x84/0xb0
        [<fffffe0000668678>] panic+0xf4/0x220
        [<fffffe000018ec78>] free_reserved_area+0x0/0x110
        [<fffffe000018edd8>] free_pages+0x50/0x88
        [<fffffe00000a759c>] kvm_free_stage2_pgd+0x30/0x40
        [<fffffe00000a5354>] kvm_arch_destroy_vm+0x18/0x44
        [<fffffe00000a1854>] kvm_put_kvm+0xf0/0x184
        [<fffffe00000a1938>] kvm_vm_release+0x10/0x1c
        [<fffffe00001edc1c>] __fput+0xb0/0x288
        [<fffffe00001ede4c>] ____fput+0xc/0x14
        [<fffffe00000d5a2c>] task_work_run+0xa8/0x11c
        [<fffffe0000095c14>] do_notify_resume+0x54/0x58
      
      In arch/arm/kvm/mmu.c:unmap_range(), we end up doing an extra put_page()
      on the stage2 pgd which leads to the BUG in put_page_testzero(). This
      happens because a pud_huge() test in unmap_range() returns true when it
      should always be false with 2-level pages tables used by 64k pages.
      This patch removes support for huge puds if 2-level pagetables are
      being used.
      Signed-off-by: default avatarMark Salter <msalter@redhat.com>
      [catalin.marinas@arm.com: removed #ifndef around PUD_SIZE check]
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Cc: <stable@vger.kernel.org> # v3.11+
      4797ec2d
  12. 11 Sep, 2013 1 commit
    • Naoya Horiguchi's avatar
      mm: migrate: check movability of hugepage in unmap_and_move_huge_page() · 83467efb
      Naoya Horiguchi authored
      Currently hugepage migration works well only for pmd-based hugepages
      (mainly due to lack of testing,) so we had better not enable migration of
      other levels of hugepages until we are ready for it.
      
      Some users of hugepage migration (mbind, move_pages, and migrate_pages) do
      page table walk and check pud/pmd_huge() there, so they are safe.  But the
      other users (softoffline and memory hotremove) don't do this, so without
      this patch they can try to migrate unexpected types of hugepages.
      
      To prevent this, we introduce hugepage_migration_support() as an
      architecture dependent check of whether hugepage are implemented on a pmd
      basis or not.  And on some architecture multiple sizes of hugepages are
      available, so hugepage_migration_support() also checks hugepage size.
      Signed-off-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Hillf Danton <dhillf@gmail.com>
      Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      83467efb
  13. 14 Jun, 2013 1 commit
    • Steve Capper's avatar
      ARM64: mm: HugeTLB support. · 084bd298
      Steve Capper authored
      Add huge page support to ARM64, different huge page sizes are
      supported depending on the size of normal pages:
      
      PAGE_SIZE is 4KB:
         2MB - (pmds) these can be allocated at any time.
      1024MB - (puds) usually allocated on bootup with the command line
               with something like: hugepagesz=1G hugepages=6
      
      PAGE_SIZE is 64KB:
       512MB - (pmds) usually allocated on bootup via command line.
      Signed-off-by: default avatarSteve Capper <steve.capper@linaro.org>
      Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      084bd298