linux/arch/x86
Andi Kleen 42d7395feb mm: support more pagesizes for MAP_HUGETLB/SHM_HUGETLB
There was some desire in large applications using MAP_HUGETLB or
SHM_HUGETLB to use 1GB huge pages on some mappings, and stay with 2MB on
others.  This is useful together with NUMA policy: use 2MB interleaving
on some mappings, but 1GB on local mappings.

This patch extends the IPC/SHM syscall interfaces slightly to allow
specifying the page size.

It borrows some upper bits in the existing flag arguments and allows
encoding the log of the desired page size in addition to the *_HUGETLB
flag.  When 0 is specified the default size is used, this makes the
change fully compatible.

Extending the internal hugetlb code to handle this is straight forward.
Instead of a single mount it just keeps an array of them and selects the
right mount based on the specified page size.  When no page size is
specified it uses the mount of the default page size.

The change is not visible in /proc/mounts because internal mounts don't
appear there.  It also has very little overhead: the additional mounts
just consume a super block, but not more memory when not used.

I also exported the new flags to the user headers (they were previously
under __KERNEL__).  Right now only symbols for x86 and some other
architecture for 1GB and 2MB are defined.  The interface should already
work for all other architectures though.  Only architectures that define
multiple hugetlb sizes actually need it (that is currently x86, tile,
powerpc).  However tile and powerpc have user configurable hugetlb
sizes, so it's not easy to add defines.  A program on those
architectures would need to query sysfs and use the appropiate log2.

[akpm@linux-foundation.org: cleanups]
[rientjes@google.com: fix build]
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-11 17:22:25 -08:00
..
boot x86, efi: Fix processor-specific memcpy() build error 2012-11-20 20:52:07 +00:00
configs x86/Kconfig: Turn off DEBUG_NX_TEST module in defconfigs 2012-09-05 10:43:12 +02:00
crypto crypto: aesni - fix XTS mode on x86-32, add wrapper function for asmlinkage aesni_enc() 2012-10-18 14:01:33 -07:00
ia32 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-10-10 12:02:25 +09:00
include mm: support more pagesizes for MAP_HUGETLB/SHM_HUGETLB 2012-12-11 17:22:25 -08:00
kernel Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-12-01 13:08:36 -08:00
kvm x86, kvm: Remove incorrect redundant assembly constraint 2012-11-26 15:52:48 -08:00
lguest virtio: remove CONFIG_VIRTIO_RING 2012-09-28 15:05:15 +09:30
lib UAPI: x86: Fix insn_sanity build failure after UAPI split 2012-10-02 18:01:56 +01:00
math-emu x86: Rename trap_no to trap_nr in thread_struct 2012-03-13 06:24:09 +01:00
mm x86, mm: Correct vmflag test for checking VM_HUGETLB 2012-11-14 15:03:20 -08:00
net x86: bpf_jit_comp: add XOR instruction for BPF JIT 2012-09-24 16:54:35 -04:00
oprofile oprofile, x86: Fix wrapping bug in op_x86_get_ctrl() 2012-10-15 14:38:24 +02:00
pci x86/ce4100: Fix PCI configuration register access for devices without interrupts 2012-10-30 10:16:47 +01:00
platform x86/ce4100: Fix reboot by forcing the reboot method to be KBD 2012-10-30 10:16:46 +01:00
power x86, kvm: Call restore_sched_clock_state() only after %gs is initialized 2012-04-02 13:53:00 +02:00
realmode x86, suspend: Correct the restore of CR4, EFER; skip computing EFLAGS.ID 2012-10-02 08:42:31 +02:00
syscalls Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2012-10-10 12:02:25 +09:00
tools UAPI: x86: Fix the test_get_len tool 2012-10-02 18:01:56 +01:00
um Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
vdso time: Convert x86_64 to using new update_vsyscall 2012-09-24 12:38:09 -04:00
video x86: Use vga_default_device() when determining whether an fb is primary 2012-04-24 09:50:17 +01:00
xen xen/mmu: Use Xen specific TLB flush instead of the generic one. 2012-10-31 12:38:31 -04:00
.gitignore x86/kprobes: Add arch/x86/tools/insn_sanity to .gitignore 2012-01-16 08:21:59 +01:00
Kbuild x86, realmode: realmode.bin infrastructure 2012-05-08 11:41:48 -07:00
Kconfig Merge branch 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux 2012-10-14 13:39:34 -07:00
Kconfig.cpu x86/Kconfig: Clean up Kconfig defaults 2012-09-13 17:45:33 +02:00
Kconfig.debug x86/tlb: add tlb_flushall_shift knob into debugfs 2012-06-27 19:29:10 -07:00
Makefile kbuild: Fix accidental revert in commit fe04ddf 2012-10-15 13:01:05 -07:00
Makefile_32.cpu
Makefile.um um: fix linker script generation 2012-04-09 13:59:00 -04:00