linux/include/asm-ia64
Badari Pulavarty f6b3ec238d [PATCH] madvise(MADV_REMOVE): remove pages from tmpfs shm backing store
Here is the patch to implement madvise(MADV_REMOVE) - which frees up a
given range of pages & its associated backing store.  Current
implementation supports only shmfs/tmpfs and other filesystems return
-ENOSYS.

"Some app allocates large tmpfs files, then when some task quits and some
client disconnect, some memory can be released.  However the only way to
release tmpfs-swap is to MADV_REMOVE". - Andrea Arcangeli

Databases want to use this feature to drop a section of their bufferpool
(shared memory segments) - without writing back to disk/swap space.

This feature is also useful for supporting hot-plug memory on UML.

Concerns raised by Andrew Morton:

- "We have no plan for holepunching!  If we _do_ have such a plan (or
  might in the future) then what would the API look like?  I think
  sys_holepunch(fd, start, len), so we should start out with that."

- Using madvise is very weird, because people will ask "why do I need to
  mmap my file before I can stick a hole in it?"

- None of the other madvise operations call into the filesystem in this
  manner.  A broad question is: is this capability an MM operation or a
  filesytem operation?  truncate, for example, is a filesystem operation
  which sometimes has MM side-effects.  madvise is an mm operation and with
  this patch, it gains FS side-effects, only they're really, really
  significant ones."

Comments:

- Andrea suggested the fs operation too but then it's more efficient to
  have it as a mm operation with fs side effects, because they don't
  immediatly know fd and physical offset of the range.  It's possible to
  fixup in userland and to use the fs operation but it's more expensive,
  the vmas are already in the kernel and we can use them.

Short term plan &  Future Direction:

- We seem to need this interface only for shmfs/tmpfs files in the short
  term.  We have to add hooks into the filesystem for correctness and
  completeness.  This is what this patch does.

- In the future, plan is to support both fs and mmap apis also.  This
  also involves (other) filesystem specific functions to be implemented.

- Current patch doesn't support VM_NONLINEAR - which can be addressed in
  the future.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Andrea Arcangeli <andrea@suse.de>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:33:22 -08:00
..
sn [IA64-SGI] altix: pci_window fixup 2005-12-06 09:09:23 -08:00
a.out.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
acpi-ext.h [ACPI] fix IA64 build warning 2005-08-04 22:29:34 -04:00
acpi.h [IA64] Add ACPI based P-state support 2005-08-26 15:09:24 -07:00
agp.h [PATCH] AGP fix for Xen VMM 2005-06-07 12:35:43 -07:00
asmmacro.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
atomic.h [PATCH] atomic: inc_not_zero 2005-11-13 18:14:16 -08:00
auxvec.h [PATCH] auxiliary vector cleanups 2005-09-07 16:57:21 -07:00
bitops.h [FLS64]: generic version 2006-01-03 13:11:06 -08:00
break.h [PATCH] Kprobes/IA64: kdebug die notification mechanism 2005-06-23 09:45:22 -07:00
bug.h [PATCH] remove all kernel BUGs 2005-05-01 08:59:01 -07:00
bugs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
byteorder.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cache.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cacheflush.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
checksum.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
compat.h [PATCH] compat: be more consistent about [ug]id_t 2005-09-07 16:57:19 -07:00
cpu.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cputime.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
current.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cyclone.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
delay.h [IA64] disable preemption in udelay() 2005-12-16 10:00:24 -08:00
div64.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
dma-mapping.h [PATCH] ia64: re-implement dma_get_cache_alignment to avoid EXPORT_SYMBOL 2005-11-07 07:53:23 -08:00
dma.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
elf.h [PATCH] auxiliary vector cleanups 2005-09-07 16:57:21 -07:00
emergency-restart.h [PATCH] Add emergency_restart() 2005-07-26 14:35:41 -07:00
errno.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
fcntl.h [PATCH] Clean up struct flock definitions 2005-09-07 16:57:38 -07:00
fpswa.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
fpu.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
futex.h [PATCH] Remove unused var from asm/futex.h 2005-09-21 16:16:29 -07:00
gcc_intrin.h [IA64] fix fls() 2005-04-21 11:07:59 -07:00
hardirq.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
hw_irq.h [PATCH] x86/x86_64: deferred handling of writes to /proc/irqxx/smp_affinity 2005-09-07 16:57:15 -07:00
ia32.h [IA64] Change SET_PERSONALITY to comply with comment in binfmt_elf.c. 2005-12-06 09:12:34 -08:00
ia64regs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ide.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
intel_intrin.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
intrinsics.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
io.h Pull rationalise-regions into release branch 2005-08-29 15:50:32 -07:00
ioctl.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ioctls.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
iosapic.h [IA64] Minor cleanups - remove unnecessary function prototype in iosapic.h 2005-09-07 14:00:40 -07:00
ipcbuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
irq.h [IA64] Manual merge fix for 3 files 2005-09-08 14:27:13 -07:00
kdebug.h [IA64] Extend notify_die() hooks for IA64 2005-11-07 11:27:13 -08:00
kmap_types.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
kprobes.h [PATCH] Kprobes: Track kprobe on a per_cpu basis - ia64 changes 2005-11-07 07:53:45 -08:00
kregs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
linkage.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
local.h [IA64] Fix missing parameter for local_add/sub 2005-12-07 11:30:11 -08:00
machvec_dig.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
machvec_hpsim.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
machvec_hpzx1_swiotlb.h [IA64] more robust zx1/sx1000 machvec support 2005-09-14 16:22:11 -07:00
machvec_hpzx1.h [IA64] more robust zx1/sx1000 machvec support 2005-09-14 16:22:11 -07:00
machvec_init.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
machvec_sn2.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
machvec.h Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 2005-10-28 21:09:26 -07:00
mc146818rtc.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mca_asm.h [PATCH] MCA/INIT: use per cpu stacks 2005-09-11 14:08:41 -07:00
mca.h [IA64] Wire in the MCA/INIT handler stacks 2005-09-22 13:24:19 -07:00
meminit.h Pull sparsemem-v5 into release branch 2005-10-28 14:32:56 -07:00
mman.h [PATCH] madvise(MADV_REMOVE): remove pages from tmpfs shm backing store 2006-01-06 08:33:22 -08:00
mmu_context.h [IA64] make mmu_context.h and tlb.c 80-column friendly 2005-11-03 14:43:50 -08:00
mmu.h [IA64] Fix race in mm-context wrap-around logic. 2005-08-12 15:05:21 -07:00
mmzone.h [PATCH] V5 ia64 SPARSEMEM - conditional changes for SPARSEMEM 2005-10-04 13:21:13 -07:00
module.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
msgbuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
msi.h [PATCH] PCI: Change MSI to use physical delivery mode always 2005-11-10 16:09:18 -08:00
namei.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
nodedata.h [PATCH] V5 ia64 SPARSEMEM - conditional changes for SPARSEMEM 2005-10-04 13:21:13 -07:00
numa.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
numnodes.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
page.h [IA64] - Make pfn_valid more precise for SGI Altix systems 2005-11-29 09:24:10 -08:00
pal.h [IA64] Add ACPI based P-state support 2005-08-26 15:09:24 -07:00
param.h [PATCH] ia64: Selectable Timer Interrupt Frequency 2005-06-23 09:45:10 -07:00
parport.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
patch.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pci.h [PATCH] Make sparc64 use setup-res.c 2005-09-08 14:57:25 -07:00
percpu.h [PATCH] adjust per_cpu definition in non-SMP case 2005-06-23 09:45:28 -07:00
perfmon_default_smpl.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
perfmon.h [IA64] alternate perfmon handler 2005-05-18 16:14:30 -07:00
pgalloc.h [IA64] 4-level page tables 2005-11-11 09:37:29 -08:00
pgtable.h [IA64] 4-level page tables 2005-11-11 09:37:29 -08:00
poll.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
posix_types.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
processor.h [PATCH] cpusets: Move the ia64 domain setup code to the generic code 2005-09-07 16:57:40 -07:00
ptrace_offsets.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ptrace.h [PATCH] consolidate sys_ptrace() 2005-11-07 07:53:42 -08:00
resource.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
rse.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
rwsem.h [PATCH] add sem_is_read/write_locked() 2005-10-29 21:40:35 -07:00
sal.h [IA64] Split 16-bit severity field in sal_log_record_header 2005-12-13 10:41:49 -08:00
scatterlist.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sections.h [PATCH] kprobes/ia64: refuse kprobe on ivt code 2005-06-27 15:23:54 -07:00
segment.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
semaphore.h [PATCH] semaphore: Remove __MUTEX_INITIALIZER() 2005-10-30 17:37:27 -08:00
sembuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
serial.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
setup.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
shmbuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
shmparam.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sigcontext.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
siginfo.h [PATCH] consolidate SIGEV_PAD_SIZE 2005-05-01 08:59:08 -07:00
signal.h [PATCH] asm/signal.h unification 2005-05-04 07:33:15 -07:00
smp.h [PATCH] smp_processor_id() cleanup 2005-06-21 18:46:13 -07:00
socket.h [NET]: Introduce SO_{SND,RCV}BUFFORCE socket options 2005-08-29 15:31:35 -07:00
sockios.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sparsemem.h [PATCH] V5 ia64 SPARSEMEM - conditional changes for SPARSEMEM 2005-10-04 13:21:13 -07:00
spinlock_types.h [PATCH] spinlock consolidation 2005-09-10 10:06:21 -07:00
spinlock.h [IA64] Define an ia64 version of __raw_read_trylock 2005-12-12 08:54:18 -08:00
stat.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
statfs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
string.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
suspend.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
system.h [PATCH] Prefetch kernel stacks to speed up context switch 2005-09-09 13:57:31 -07:00
termbits.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
termios.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
thread_info.h [IA64] fix circular dependency on generation of asm-offsets.h 2005-09-13 08:50:39 -07:00
timex.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
tlb.h [PATCH] mm: tlb_finish_mmu forget rss 2005-10-29 21:40:37 -07:00
tlbflush.h [IA64] Use bitmaps for efficient context allocation/free 2005-10-31 14:36:05 -08:00
topology.h [PATCH] x86_64/ia64 : Fix compilation error for node_to_first_cpu 2005-12-24 12:30:22 -08:00
types.h [PATCH] sab: consolidate kmem_bufctl_t 2005-09-05 00:05:48 -07:00
uaccess.h [PATCH] ia64 basic __user annotations 2005-09-29 08:46:27 -07:00
ucontext.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
unaligned.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
uncached.h [PATCH] ia64 uncached alloc 2005-06-21 18:46:18 -07:00
unistd.h [PATCH] unify sys_ptrace prototype 2005-10-30 17:37:20 -08:00
unwind.h [IA64] MCA/INIT: remove obsolete unwind code 2005-09-11 14:09:34 -07:00
user.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ustack.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vga.h [IA64-SGI] pcdp: add PCDP pci interface support 2005-06-28 09:09:06 -07:00
xor.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00