linux/include/asm-powerpc
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
..
iseries modify defines according to _ASM_POWERPC_ISERIES_ 2005-11-02 15:53:01 +11:00
8253pit.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
a.out.h [PATCH] powerpc: Merge include/asm-ppc*/a.out.h into include/asm-powerpc 2005-09-21 19:21:08 +10:00
abs_addr.h [PATCH] powerpc: Move various ppc64 files with no ppc32 equivalent to powerpc 2005-11-10 11:24:04 +11:00
agp.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
asm-compat.h [PATCH] powerpc: Consolidate asm compatibility macros 2005-11-10 13:10:38 +11:00
atomic.h [PATCH] atomic: inc_not_zero 2005-11-13 18:14:16 -08:00
auxvec.h [PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel 2005-11-11 22:25:39 +11:00
backlight.h powerpc: Merged asm/backlight.h 2005-10-11 09:59:38 +10:00
bitops.h [FLS64]: generic version 2006-01-03 13:11:06 -08:00
btext.h powerpc: Move a bunch of ppc64 headers to include/asm-powerpc 2005-11-14 17:22:01 +11:00
bug.h [PATCH] powerpc: Consolidate asm compatibility macros 2005-11-10 13:10:38 +11:00
bugs.h [PATCH] powerpc: Make check_bugs() static inline 2005-09-09 22:11:35 +10:00
byteorder.h [PATCH] powerpc: merge byteorder.h 2005-09-28 15:42:53 +10:00
cache.h [PATCH] powerpc: Merge cacheflush.h and cache.h 2005-11-10 13:09:22 +11:00
cacheflush.h [PATCH] powerpc: Merge cacheflush.h and cache.h 2005-11-10 13:09:22 +11:00
checksum.h [PATCH] powerpc: merge include/asm-ppc*/checksum.h into include/asm-powerpc/checksum.h 2005-10-26 15:54:31 +10:00
compat.h [PATCH] powerpc: Move various ppc64 files with no ppc32 equivalent to powerpc 2005-11-10 11:24:04 +11:00
cputable.h [PATCH] powerpc: merge align.c 2005-11-18 14:39:23 +11:00
cputime.h [PATCH] Move the identical files from include/asm-ppc{,64} 2005-08-30 13:32:05 +10:00
current.h [PATCH] powerpc: Merge current.h 2005-11-10 11:23:53 +11:00
dbdma.h powerpc: Merge various powermac-related header files. 2005-10-20 20:53:39 +10:00
delay.h powerpc: Fix delay functions for 601 processors 2005-11-18 14:08:12 +11:00
div64.h [PATCH] Move the identical files from include/asm-ppc{,64} 2005-08-30 13:32:05 +10:00
dma-mapping.h powerpc: merge dma-mapping.h 2005-11-19 01:48:52 +11:00
dma.h [PATCH] powerpc: Merge asm-ppc*/dma.h 2005-09-22 21:03:33 +10:00
eeh_event.h [PATCH] ppc64: PCI error event dispatcher 2005-11-10 11:38:05 +11:00
eeh.h [PATCH] Avoid use of uninitialised spinlock in EEH. 2005-11-17 16:53:38 +11:00
elf.h [PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel 2005-11-11 22:25:39 +11:00
emergency-restart.h [PATCH] Move the identical files from include/asm-ppc{,64} 2005-08-30 13:32:05 +10:00
errno.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
fcntl.h [PATCH] Consolidate the asm-ppc*/fcntl.h files into asm-powerpc 2005-09-07 16:57:39 -07:00
firmware.h [PATCH] powerpc: merge code values for identifying platforms 2005-11-10 13:37:51 +11:00
floppy.h powerpc: Move a bunch of ppc64 headers to include/asm-powerpc 2005-11-14 17:22:01 +11:00
futex.h [PATCH] powerpc: Consolidate asm compatibility macros 2005-11-10 13:10:38 +11:00
grackle.h powerpc: Pull out MPC106 (grackle) initialization code into its own file 2005-10-26 17:16:38 +10:00
hardirq.h powerpc: Get 64-bit configs to compile with ARCH=powerpc 2005-10-10 22:50:37 +10:00
heathrow.h powerpc: Merge various powermac-related header files. 2005-10-20 20:53:39 +10:00
hvcall.h [PATCH] powerpc: Move more ppc64 files with no ppc32 equivalent to powerpc 2005-11-10 15:32:37 +11:00
hvconsole.h powerpc: Move a bunch of ppc64 headers to include/asm-powerpc 2005-11-14 17:22:01 +11:00
hvcserver.h powerpc: Move a bunch of ppc64 headers to include/asm-powerpc 2005-11-14 17:22:01 +11:00
hw_irq.h ppc64: remove ppc_irq_dispatch_handler 2005-11-09 16:19:53 +11:00
i8259.h powerpc: Merge i8259.c into arch/powerpc/sysdev 2005-10-26 16:47:42 +10:00
ide.h powerpc: merge ide.h 2005-11-08 12:20:34 +11:00
io.h powerpc: Trivially merge several headers from asm-ppc64 to asm-powerpc 2005-11-19 20:17:32 +11:00
ioctl.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
ioctls.h powerpc: remove duplicate ioctl definitions 2005-11-01 14:36:30 +11:00
iommu.h [PATCH] powerpc: update my email address 2005-11-23 21:23:20 +11:00
ipc.h [PATCH] Move the identical files from include/asm-ppc{,64} 2005-08-30 13:32:05 +10:00
ipcbuf.h [PATCH] powerpc: Keep fixing merged ipcbuf.h 2005-11-03 16:58:17 +11:00
irq.h [PATCH] ppc32: fix PQ2 PCI DMA interrupt handling 2005-11-11 22:19:56 +11:00
kdebug.h powerpc: clean up after powermac build merge 2005-09-27 13:51:59 +10:00
kexec.h [PATCH] powerpc: Export htab start/end via device tree 2005-11-14 16:34:06 +11:00
keylargo.h powerpc: Merge various powermac-related header files. 2005-10-20 20:53:39 +10:00
kmap_types.h [PATCH] powerpc: Merge kmap_types.h 2005-09-19 09:38:49 +10:00
kprobes.h [PATCH] Kprobes: Track kprobe on a per_cpu basis - ppc64 changes 2005-11-07 07:53:45 -08:00
linkage.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
lmb.h powerpc: Merge in the ppc64 version of the prom code. 2005-10-06 12:06:20 +10:00
local.h [PATCH] Move all the very similar files to asm-powerpc 2005-08-30 13:32:06 +10:00
lppaca.h [PATCH] powerpc: Move various ppc64 files with no ppc32 equivalent to powerpc 2005-11-10 11:24:04 +11:00
machdep.h [PATCH] powerpc: Turn cpu_irq_down into kexec_cpu_down 2005-11-14 16:33:09 +11:00
macio.h powerpc: Merge various powermac-related header files. 2005-10-20 20:53:39 +10:00
mc146818rtc.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
mediabay.h powerpc: Merge various powermac-related header files. 2005-10-20 20:53:39 +10:00
mman.h [PATCH] madvise(MADV_REMOVE): remove pages from tmpfs shm backing store 2006-01-06 08:33:22 -08:00
mmu_context.h powerpc: Trivially merge several headers from asm-ppc64 to asm-powerpc 2005-11-19 20:17:32 +11:00
mmu.h [PATCH] powerpc: Add missing icache flushes for hugepages 2005-12-09 16:30:48 +11:00
mmzone.h powerpc: Trivially merge several headers from asm-ppc64 to asm-powerpc 2005-11-19 20:17:32 +11:00
module.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
mpic.h powerpc: Move smp_mpic_message_pass into mpic.c 2005-10-20 17:09:51 +10:00
msgbuf.h [PATCH] powerpc: Merge a few more include files 2005-09-09 22:11:35 +10:00
namei.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
numnodes.h [PATCH] powerpc: Merge (move) numnodes.h and sparsemem.h 2005-11-02 15:25:42 +11:00
nvram.h powerpc: Remove an extraneous and incorrect declaration of pmac_nvram_init. 2005-11-15 11:17:02 +11:00
of_device.h powerpc: Merge of_device.c and of_device.h 2005-10-06 13:22:17 +10:00
ohare.h powerpc: Merge various powermac-related header files. 2005-10-20 20:53:39 +10:00
oprofile_impl.h [PATCH] powerpc: merge oprofile headers 2005-09-21 19:21:08 +10:00
paca.h [PATCH] powerpc: Move various ppc64 files with no ppc32 equivalent to powerpc 2005-11-10 11:24:04 +11:00
page_32.h powerpc: Fix 32-bit compile: PPC_MEMSTART was undeclared 2005-11-14 17:32:50 +11:00
page_64.h [PATCH] powerpc: More hugepage boundary case fixes 2005-11-25 22:12:45 +11:00
page.h [PATCH] powerpc: Merge page.h 2005-11-14 16:33:05 +11:00
param.h [PATCH] powerpc: Merge a few more include files 2005-09-09 22:11:35 +10:00
parport.h [PATCH] powerpc: Merge parport.h 2005-10-27 20:50:54 +10:00
pci-bridge.h powerpc: Trivially merge several headers from asm-ppc64 to asm-powerpc 2005-11-19 20:17:32 +11:00
pci.h powerpc: Merge pci.h 2005-11-19 20:46:04 +11:00
percpu.h [PATCH] Move all the very similar files to asm-powerpc 2005-08-30 13:32:06 +10:00
pgalloc.h powerpc: Trivially merge several headers from asm-ppc64 to asm-powerpc 2005-11-19 20:17:32 +11:00
pgtable-4k.h powerpc: Trivially merge several headers from asm-ppc64 to asm-powerpc 2005-11-19 20:17:32 +11:00
pgtable-64k.h powerpc: Trivially merge several headers from asm-ppc64 to asm-powerpc 2005-11-19 20:17:32 +11:00
pgtable.h powerpc: Trivially merge several headers from asm-ppc64 to asm-powerpc 2005-11-19 20:17:32 +11:00
pmac_feature.h powerpc: Merge various powermac-related header files. 2005-10-20 20:53:39 +10:00
pmac_low_i2c.h powerpc: Merge various powermac-related header files. 2005-10-20 20:53:39 +10:00
pmc.h [PATCH] ppc32: fix perf_irq extern on e500 2005-11-09 07:55:52 -08:00
poll.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
posix_types.h [PATCH] powerpc: Merge asm-ppc*/posix_types.h 2005-09-21 19:21:07 +10:00
ppc_asm.h [PATCH] powerpc: Consolidate asm compatibility macros 2005-11-10 13:10:38 +11:00
ppc-pci.h powerpc: Merge pci.h 2005-11-19 20:46:04 +11:00
processor.h [PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel 2005-11-11 22:25:39 +11:00
prom.h [PATCH] ppc64: SMU partition recovery 2005-11-08 11:17:40 +11:00
pSeries_reconfig.h powerpc: Merge in the ppc64 version of the prom code. 2005-10-06 12:06:20 +10:00
ptrace.h powerpc: merge ptrace.h 2005-11-03 16:03:07 +11:00
reg_8xx.h [PATCH] powerpc: Merge cacheflush.h and cache.h 2005-11-10 13:09:22 +11:00
reg.h [PATCH] powerpc: merge code values for identifying platforms 2005-11-10 13:37:51 +11:00
resource.h [PATCH] Move all the very similar files to asm-powerpc 2005-08-30 13:32:06 +10:00
rtas.h powerpc: Merge remaining RTAS code 2005-11-03 14:41:19 +11:00
rtc.h powerpc: Make set_rtc_time() return error code from lower-level function 2005-10-22 15:57:55 +10:00
rwsem.h Merge ../linux-2.6 by hand 2005-10-31 13:37:12 +11:00
scatterlist.h [PATCH] powerpc: merge scatterlist.h 2005-10-27 16:45:52 +10:00
seccomp.h [PATCH] powerpc: Merge asm-ppc*/seccomp.h, drop TIF_32BIT check 2005-09-25 22:38:45 +10:00
sections.h [PATCH] powerpc: Merge simplified sections.h into asm-powerpc 2005-09-19 09:38:50 +10:00
semaphore.h Merge ../linux-2.6 by hand 2005-10-31 13:37:12 +11:00
sembuf.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
serial.h powerpc: Move a bunch of ppc64 headers to include/asm-powerpc 2005-11-14 17:22:01 +11:00
setup.h [PATCH] powerpc: Merge a few more include files 2005-09-09 22:11:35 +10:00
shmbuf.h [PATCH] powerpc: Fix __power64__ typos that should be __powerpc64__ 2005-09-09 22:11:35 +10:00
shmparam.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
sigcontext.h powerpc: merge sigcontext.h 2005-11-03 16:24:25 +11:00
siginfo.h [PATCH] ppc64: Add definitions for new PTRACE calls 2005-09-12 17:19:12 +10:00
signal.h [PATCH] powerpc: Merge signal.h 2005-11-10 11:23:46 +11:00
smp.h powerpc: Various UP build fixes 2005-11-07 13:18:13 +11:00
smu.h [PATCH] ppc64: SMU partition recovery 2005-11-08 11:17:40 +11:00
socket.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
sockios.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
sparsemem.h [PATCH] ppc64: Increase sparsemem defaults 2005-11-11 22:21:41 +11:00
spinlock_types.h [PATCH] powerpc: merge include/asm-ppc*/spinlock_types.h into include/asm-powerpc/spinlock_types.h 2005-09-21 19:21:09 +10:00
spinlock.h powerpc: Merge spinlock.h 2005-11-19 20:50:46 +11:00
sstep.h powerpc: Make single-stepping emulation (mostly) usable on 32-bit 2005-10-28 22:48:08 +10:00
stat.h powerpc: merge stat.h 2005-11-03 16:02:23 +11:00
statfs.h [PATCH] powerpc: merge include/asm-ppc*/statfs.h into include/asm-powerpc/statfs.h 2005-09-21 19:21:10 +10:00
string.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
synch.h [PATCH] powerpc: merge atomic.h, memory.h 2005-09-25 22:38:46 +10:00
system.h powerpc: Move some extern declarations from C code into headers 2005-11-10 15:53:40 +11:00
tce.h [PATCH] powerpc: update my email address 2005-11-23 21:23:20 +11:00
termbits.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
termios.h powerpc: use asm-generic/termios.h 2005-11-01 14:36:55 +11:00
thread_info.h [PATCH] ppc64: support 64k pages 2005-11-06 16:56:47 -08:00
time.h merge filename and modify references to iseries/hv_call.h 2005-11-01 16:59:20 +11:00
timex.h [PATCH] ppc32: Fix timekeeping 2005-10-12 08:24:47 -07:00
tlb.h powerpc: merge tlb.h 2005-11-04 10:20:27 +11:00
tlbflush.h [PATCH] ppc64: support 64k pages 2005-11-06 16:56:47 -08:00
topology.h [PATCH] powerpc: Fix typo in topology.h 2005-11-18 13:18:11 +11:00
types.h [PATCH] ppc64: make dma_addr_t 64 bits 2005-10-27 16:45:50 +10:00
uaccess.h [PATCH] powerpc: Consolidate asm compatibility macros 2005-11-10 13:10:38 +11:00
ucontext.h powerpc: merge ucontext.h 2005-11-03 16:59:17 +11:00
udbg.h [PATCH] powerpc: Move udbg code to arch/powerpc 2005-11-11 22:23:34 +11:00
unaligned.h [PATCH] powerpc: Standardize on _ASM_POWERPC header symbol prefix 2005-09-09 22:11:34 +10:00
uninorth.h powerpc: Merge various powermac-related header files. 2005-10-20 20:53:39 +10:00
unistd.h Merge ../linux-2.6 by hand 2005-10-31 13:37:12 +11:00
user.h [PATCH] powerpc: Merge a few more include files 2005-09-09 22:11:35 +10:00
vdso_datapage.h [PATCH] powerpc: vdso fixes (take #2) 2005-11-14 16:35:58 +11:00
vdso.h [PATCH] powerpc: Make the vDSO functions set error code (#2) 2005-11-16 14:05:11 +11:00
vga.h [PATCH] powerpc: Merge asm-ppc*/vga.h 2005-09-21 19:21:09 +10:00
vio.h powerpc: Add a shutdown member to vio_driver 2005-10-24 17:40:23 +10:00
xmon.h powerpc: Simplify and clean up the xmon terminal I/O 2005-11-08 22:55:08 +11:00
xor.h [PATCH] Move the identical files from include/asm-ppc{,64} 2005-08-30 13:32:05 +10:00