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
..
arch-aaec2000
[ARM] 3060/1: allow constants found in asm/memory.h to be used in asm code
2005-10-29 21:44:55 +01:00
arch-cl7500
[ARM] 3060/1: allow constants found in asm/memory.h to be used in asm code
2005-10-29 21:44:55 +01:00
arch-clps711x
[ARM] Include asm/hardware.h instead of asm/arch/hardware.h
2005-11-16 14:51:20 +00:00
arch-ebsa110
[ARM] ebsa110: __arch_ioremap should be 3 args
2005-11-21 15:26:52 +00:00
arch-ebsa285
[ARM] 3060/1: allow constants found in asm/memory.h to be used in asm code
2005-10-29 21:44:55 +01:00
arch-epxa10db
[ARM] Include asm/hardware.h instead of asm/arch/hardware.h
2005-11-16 14:51:20 +00:00
arch-h720x
[ARM] Include asm/hardware.h instead of asm/arch/hardware.h
2005-11-16 14:51:20 +00:00
arch-imx
[ARM] Include asm/hardware.h instead of asm/arch/hardware.h
2005-11-16 14:51:20 +00:00
arch-integrator
[ARM] Include asm/hardware.h instead of asm/arch/hardware.h
2005-11-16 14:51:20 +00:00
arch-iop3xx
[ARM] 3173/1: Fix to allow 2.6.15-rc2 to compile for IOP3xx boards
2005-11-23 22:45:27 +00:00
arch-ixp4xx
[ARM] 3171/1: To add missing QMGR region size for IXP4XX
2005-11-21 15:17:07 +00:00
arch-ixp2000
[ARM] 3086/1: ixp2xxx error irq handling
2005-11-04 17:15:44 +00:00
arch-l7200
[ARM] Include asm/hardware.h instead of asm/arch/hardware.h
2005-11-16 14:51:20 +00:00
arch-lh7a40x
[ARM] 3060/1: allow constants found in asm/memory.h to be used in asm code
2005-10-29 21:44:55 +01:00
arch-omap
[ARM] Include asm/hardware.h instead of asm/arch/hardware.h
2005-11-16 14:51:20 +00:00
arch-pxa
[PATCH] USB: pxa27x OHCI - Separate platform code from main driver
2006-01-04 13:48:28 -08:00
arch-realview
[ARM] Fix arch-realview/system.h to use __io_address()
2005-11-16 14:38:19 +00:00
arch-rpc
[ARM] Include asm/hardware.h instead of asm/arch/hardware.h
2005-11-16 14:51:20 +00:00
arch-s3c2410
[ARM] 3178/1: S3C2400 - adds GPIO registers definitions to regs-gpio.h
2005-11-28 18:08:43 +00:00
arch-sa1100
[ARM] Remove asm/hardware.h include from SA1100 io.h
2005-11-25 15:33:12 +00:00
arch-shark
[ARM] 3060/1: allow constants found in asm/memory.h to be used in asm code
2005-10-29 21:44:55 +01:00
arch-versatile
[ARM] 3060/1: allow constants found in asm/memory.h to be used in asm code
2005-10-29 21:44:55 +01:00
hardware
[SERIAL] Fix status reporting with PL011 serial driver
2005-11-19 11:10:35 +00:00
mach
[ARM] 3057/1: Add memory control method to support OneNAND sync burst read
2005-11-09 15:15:10 +00:00
a.out.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
apm.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
assembler.h
[ARM] Clean up save_and_disable_irqs macro and allow use of ARMv6 CPSID
2005-11-09 15:04:22 +00:00
atomic.h
[ARM] Use unsigned long not u32 in atomic_cmpxchg
2005-11-16 18:03:10 +00:00
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
bug.h
[PATCH] qualifiers in return types - easy cases
2005-08-23 18:43:45 -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
[ARM] Fix ARMv6 VIPT cache >= 32K
2005-09-08 15:32:23 +01:00
checksum.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
cpu-multi32.h
[PATCH] qualifiers in return types - easy cases
2005-08-23 18:43:45 -07:00
cpu-single.h
[PATCH] qualifiers in return types - easy cases
2005-08-23 18:43:45 -07:00
cpu.h
[ARM SMP] Track CPU idle threads
2005-11-02 21:51:40 +00:00
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
delay.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
div64.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
dma-mapping.h
[PATCH] gfp_t: dma-mapping (arm)
2005-10-28 08:16:47 -07:00
dma.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
domain.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
ecard.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
elf.h
[ARM] 3205/1: Handle new EABI relocations when loading kernel modules.
2005-12-14 22:04:22 +00:00
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 flock64 definitions
2005-09-07 16:57:38 -07:00
fiq.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
floppy.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
fpstate.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
futex.h
[ARM] Fix warning in asm/futex.h
2005-09-18 21:11:08 +01:00
glue.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
hardirq.h
[ARM SMP] Add core ARM support for local timers
2005-11-08 19:08:05 +00:00
hardware.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
ide.h
[PATCH] ARM: 2758/1: Fix comment in file header to read "ARM" instead i386
2005-06-27 15:58:39 +01:00
io.h
[ARM] 3191/1: Mark I/O pointer as const in __raw_reads[bwl]
2005-12-05 10:54:59 +00:00
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
ipc.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
ipcbuf.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
irq.h
[ARM SMP] Add hotplug CPU infrastructure
2005-11-02 22:24:33 +00:00
kmap_types.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
leds.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
limits.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
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
locks.h
[ARM] 3019/1: fix wrong comments
2005-10-18 07:51:34 +01:00
mc146818rtc.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
memory.h
[ARM] 3194/1: add pfn_to_kaddr macro for ARM take2
2005-12-05 10:55:00 +00:00
mman.h
[PATCH] madvise(MADV_REMOVE): remove pages from tmpfs shm backing store
2006-01-06 08:33:22 -08:00
mmu.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
mmu_context.h
[ARM] Add linux/compiler.h includes where required
2005-11-16 17:23:57 +00:00
mmzone.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -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
mtd-xip.h
[MTD] XIP cleanup
2005-07-07 16:50:16 +02:00
namei.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
numnodes.h
[ARM] Add asm/memory.h to asm/numnodes.h
2005-11-21 15:26:18 +00:00
nwflash.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
page.h
[PATCH] mm: consolidate get_order
2005-09-05 00:05:39 -07:00
param.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
parport.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
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
pgalloc.h
[PATCH] ARM: Factor out common pmd_populate functionality
2005-06-22 20:58:29 +01:00
pgtable.h
[PATCH] vm: remove unused/broken page_pte[_prot] macros
2005-10-30 17:37:22 -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
proc-fns.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
processor.h
[PATCH] ARM: Fix kernel stack offset calculations
2005-05-05 13:11:00 +01:00
procinfo.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
ptrace.h
[PATCH] ARM: showregs
2005-04-17 15:50:36 +01:00
resource.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
rtc.h
[PATCH] ARM: RTC: allow driver methods to return error
2005-04-30 12:19:28 +01:00
scatterlist.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
sections.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
segment.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
semaphore-helper.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
semaphore.h
[ARM] sema_count() removal
2005-12-01 20:58:01 +00:00
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
[ARM] 2925/3: earlyparam - postfix section with .init for make buildcheck
2005-09-20 16:25:12 +01:00
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
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
signal.h
[ARM] Remove SA_IRQNOMASK
2005-09-26 15:30:20 +01:00
sizes.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
smp.h
[ARM SMP] Add core ARM support for local timers
2005-11-08 19:08:05 +00:00
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
spinlock.h
[ARM SMP] Use event instructions for spinlocks
2005-12-01 15:47:24 +00:00
spinlock_types.h
[PATCH] spinlock consolidation
2005-09-10 10:06:21 -07:00
stat.h
[PATCH] ARM: Fix new-ABI layout of struct stat64
2005-07-04 13:02:46 +01:00
statfs.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
string.h
[PATCH] ARM: 2653/1: Fix memset and memzero macro double-reference of parameters
2005-04-25 23:40:05 +01:00
suspend.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
system.h
[ARM] No need to include asm/proc-fns.h into asm/system.h
2005-11-16 18:36:49 +00:00
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
therm.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
thread_info.h
[ARM] Add linux/compiler.h includes where required
2005-11-16 17:23:57 +00:00
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
[PATCH] ARM SMP: TLB implementations only affect local CPU
2005-06-28 13:40:39 +01:00
topology.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
traps.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
types.h
[PATCH] sab: consolidate kmem_bufctl_t
2005-09-05 00:05:48 -07:00
uaccess.h
[ARM] Fix get_user when passed a const pointer
2005-11-18 14:22:03 +00:00
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
unistd.h
[PATCH] unify sys_ptrace prototype
2005-10-30 17:37:20 -08:00
user.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
vfp.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
vfpmacros.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
vga.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00
xor.h
Linux-2.6.12-rc2
2005-04-16 15:20:36 -07:00