Kirill A. Shutemov 33041a0d76 mm: mark remap_file_pages() syscall as deprecated ... The remap_file_pages() system call is used to create a nonlinear mapping, that is, a mapping in which the pages of the file are mapped into a nonsequential order in memory. The advantage of using remap_file_pages() over using repeated calls to mmap(2) is that the former approach does not require the kernel to create additional VMA (Virtual Memory Area) data structures. Supporting of nonlinear mapping requires significant amount of non-trivial code in kernel virtual memory subsystem including hot paths. Also to get nonlinear mapping work kernel need a way to distinguish normal page table entries from entries with file offset (pte_file). Kernel reserves flag in PTE for this purpose. PTE flags are scarce resource especially on some CPU architectures. It would be nice to free up the flag for other usage. Fortunately, there are not many users of remap_file_pages() in the wild. It's only known that one enterprise RDBMS implementation uses the syscall on 32-bit systems to map files bigger than can linearly fit into 32-bit virtual address space. This use-case is not critical anymore since 64-bit systems are widely available. The plan is to deprecate the syscall and replace it with an emulation. The emulation will create new VMAs instead of nonlinear mappings. It's going to work slower for rare users of remap_file_pages() but ABI is preserved. One side effect of emulation (apart from performance) is that user can hit vm.max_map_count limit more easily due to additional VMAs. See comment for DEFAULT_MAX_MAP_COUNT for more details on the limit. [akpm@linux-foundation.org: fix spello] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Dave Jones <davej@redhat.com> Cc: Armin Rigo <arigo@tunes.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2014-06-06 16:08:17 -07:00
..
ABI	ACPI and power management updates for 3.16-rc1	2014-06-04 08:57:16 -07:00
accounting
acpi	Documentation / ACPI: Fix location of GPIO documentation	2014-05-23 14:39:26 +02:00
aoe
arm	Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm into next	2014-06-05 15:57:04 -07:00
arm64	doc: arm64: add description of EFI stub support	2014-04-30 19:57:05 +01:00
auxdisplay
backlight
blackfin
block
blockdev	zram: propagate error to user	2014-04-07 16:36:02 -07:00
bus-devices
cdrom
cgroups	vmscan: memcg: always use swappiness of the reclaimed memcg	2014-06-06 16:08:17 -07:00
connector	w1: optional bundling of netlink kernel replies	2014-05-27 13:56:21 -07:00
console
cpu-freq	PM / OPP: Move cpufreq specific OPP functions out of generic OPP library	2014-05-07 00:39:03 +02:00
cpuidle
cris
crypto
development-process
device-mapper	dm thin: add 'no_space_timeout' dm-thin-pool module param	2014-05-20 14:30:36 -04:00
devicetree	drivers/rtc/rtc-hym8563.c: add optional clock-output-names property	2014-06-06 16:08:08 -07:00
DocBook	Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media into next	2014-06-04 14:24:30 -07:00
driver-model	Staging driver patches for 3.16-rc1	2014-06-03 08:34:00 -07:00
dvb
early-userspace
EDID
extcon
fault-injection
fb	doc: spelling error changes	2014-05-05 15:32:05 +02:00
filesystems	Documentation/filesystems/seq_file.txt: create_proc_entry deprecated	2014-06-06 16:08:11 -07:00
firmware_class
fmc
frv
gpio	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
hid	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
hwmon	New driver for NCT6683D	2014-06-03 11:09:43 -07:00
i2c	Documentation: i2c: improve section about flags mangling the protocol	2014-04-06 13:53:48 +02:00
i2o
ia64
ide
infiniband
input	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
ioctl
isdn
ja_JP	Documentation: Update stable address in Chinese and Japanese translations	2014-04-16 14:13:27 -07:00
kbuild	kconfig: make allnoconfig disable options behind EMBEDDED and EXPERT	2014-04-07 16:36:09 -07:00
kdump
ko_KR
laptops
leds
m68k
make
memory-devices
metag
mic
mips
misc-devices
mmc
mn10300
mtd	doc: spelling error changes	2014-05-05 15:32:05 +02:00
namespaces
netlabel
networking	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
nfc
parisc
PCI
pcmcia
phy
power	Merge branch 'pm-cpufreq'	2014-06-03 23:13:20 +02:00
powerpc	doc: spelling error changes	2014-05-05 15:32:05 +02:00
pps
prctl
pti
ptp	ptp: Fix compiler warnings in the testptp utility	2014-03-27 14:51:47 -04:00
rapidio	rapidio: rework device hierarchy and introduce mport class of devices	2014-04-07 16:36:07 -07:00
RCU	documentation: Update API documentation	2014-04-29 08:38:53 -07:00
s390	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
scheduler	asm/system.h: clean asm/system.h from docs	2014-04-07 16:36:11 -07:00
scsi
security	doc: spelling error changes	2014-05-05 15:32:05 +02:00
serial	tty/serial: Add GPIOLIB helpers for controlling modem lines	2014-05-28 12:49:14 -07:00
sh
sound	doc: spelling error changes	2014-05-05 15:32:05 +02:00
spi	Merge remote-tracking branches 'spi/topic/s3c64xx', 'spi/topic/sc18is602', 'spi/topic/sh-hspi', 'spi/topic/sh-msiof', 'spi/topic/sh-sci', 'spi/topic/sirf' and 'spi/topic/spidev' into spi-next	2014-03-30 00:51:34 +00:00
sysctl	sysctl: allow for strict write position handling	2014-06-06 16:08:13 -07:00
target
thermal
timers	timer_stats/doc: Fix /proc/timer_stats documentation	2014-05-04 20:46:32 +02:00
tpm
trace	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
usb	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
vDSO
video4linux	[media] exynos4-is: Remove support for non-dt platforms	2014-05-23 18:52:54 -03:00
virtual	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
vm	mm: mark remap_file_pages() syscall as deprecated	2014-06-06 16:08:17 -07:00
w1	w1: optional bundling of netlink kernel replies	2014-05-27 13:56:21 -07:00
watchdog	watchdog: it87_wdt: Work around non-working CIR interrupts	2014-03-31 13:33:55 +02:00
wimax
x86	Merge branch 'x86/espfix' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next	2014-06-05 07:46:15 -07:00
xtensa
zh_CN	driver core fixes for 3.15-rc2	2014-04-18 16:59:52 -07:00
.gitignore
00-INDEX	Merge branch 'x86-nuke-platforms-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-04-02 13:15:58 -07:00
applying-patches.txt
assoc_array.txt
atomic_ops.txt	arch,doc: Convert smp_mb__*()	2014-04-18 14:20:48 +02:00
bad_memory.txt
basic_profiling.txt
bcache.txt
binfmt_misc.txt
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
BUG-HUNTING
bus-virt-phys-mapping.txt
cachetlb.txt
Changes	doc: Note need of bc in the kernel build from 3.10 onwards	2014-05-19 16:27:20 +02:00
circular-buffers.txt
clk.txt
coccinelle.txt
CodingStyle	Documentation: expand/clarify debug documentation	2014-06-04 16:54:17 -07:00
cpu-hotplug.txt
cpu-load.txt
cputopology.txt
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt	firewire: revert to 4 GB RDMA, fix protocols using Memory Space	2014-05-29 15:50:30 +02:00
dell_rbu.txt
devices.txt	Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media	2014-04-04 09:50:07 -07:00
digsig.txt
DMA-API-HOWTO.txt	DMA-API: Update dma_pool_create ()and dma_pool_alloc() descriptions	2014-05-26 17:28:28 -06:00
DMA-API.txt	DMA-API: Capitalize "CPU" consistently	2014-05-26 17:28:27 -06:00
DMA-attributes.txt	doc: spelling error changes	2014-05-05 15:32:05 +02:00
dma-buf-sharing.txt	doc: spelling error changes	2014-05-05 15:32:05 +02:00
DMA-ISA-LPC.txt	DMA-API: Clarify physical/bus address distinction	2014-05-20 16:54:21 -06:00
dmaengine.txt
dmatest.txt
dontdiff	Documentation: LLVMLinux: Update Documentation/dontdiff	2014-04-09 13:44:34 -07:00
dynamic-debug-howto.txt	doc: spelling error changes	2014-05-05 15:32:05 +02:00
edac.txt	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial into next	2014-06-04 08:50:34 -07:00
efi-stub.txt	doc: arm64: add description of EFI stub support	2014-04-30 19:57:05 +01:00
eisa.txt
email-clients.txt	Documentation: update thunderbird email client settings	2014-05-25 12:39:00 -07:00
flexible-arrays.txt
futex-requeue-pi.txt
gcov.txt
highuid.txt
HOWTO
hsi.txt	Documentation: HSI: Add some general description for the HSI subsystem	2014-05-04 09:49:46 +02:00
hw_random.txt
hwspinlock.txt
init.txt
initrd.txt
Intel-IOMMU.txt
intel_txt.txt
io-mapping.txt
io_ordering.txt
iostats.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt	genirq: Improve documentation to match current implementation	2014-05-27 10:16:44 +02:00
IRQ.txt
irqflags-tracing.txt	asm/system.h: clean asm/system.h from docs	2014-04-07 16:36:11 -07:00
isapnp.txt
java.txt	Documentation: update java sample wrapper for java 7	2014-05-25 12:39:00 -07:00
kernel-doc-nano-HOWTO.txt
kernel-docs.txt
kernel-parameters.txt	kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump after panic_notifers	2014-06-06 16:08:12 -07:00
kernel-per-CPU-kthreads.txt
kmemcheck.txt
kmemleak.txt	mm: introduce kmemleak_update_trace()	2014-06-06 16:08:17 -07:00
kobject.txt
kprobes.txt
kref.txt
ldm.txt
local_ops.txt
lockdep-design.txt
lockstat.txt
lockup-watchdogs.txt
logo.gif
logo.txt
magic-number.txt	Documentation/serial: Delete obsolete driver documentation	2014-04-16 14:20:34 -07:00
Makefile
ManagementStyle
md.txt
media-framework.txt
memory-barriers.txt	Documentation/memory-barriers.txt: fix important typo re memory barriers	2014-06-06 16:08:11 -07:00
memory-hotplug.txt	memory-hotplug: update documentation to hide information about SECTIONS and remove end_phys_index	2014-06-04 16:53:58 -07:00
module-signing.txt	Nothing major: the stricter permissions checking for sysfs broke	2014-04-06 09:38:07 -07:00
mono.txt
mutex-design.txt
nommu-mmap.txt
numastat.txt
oops-tracing.txt	Use 'E' instead of 'X' for unsigned module taint flag.	2014-03-31 14:52:43 +10:30
padata.txt
parport-lowlevel.txt
parport.txt
percpu-rw-semaphore.txt
phy.txt
pi-futex.txt
pinctrl.txt
pnp.txt
preempt-locking.txt
printk-formats.txt	doc: printk-formats: do not mention casts for u64/s64	2014-05-05 15:32:42 +02:00
pwm.txt
ramoops.txt
rbtree.txt	doc: spelling error changes	2014-05-05 15:32:05 +02:00
remoteproc.txt
rfkill.txt	doc: spelling error changes	2014-05-05 15:32:05 +02:00
robust-futex-ABI.txt
robust-futexes.txt	doc: spelling error changes	2014-05-05 15:32:05 +02:00
rpmsg.txt
rt-mutex-design.txt
rt-mutex.txt
rtc.txt
SAK.txt
SecurityBugs
serial-console.txt
sgi-ioc4.txt
SM501.txt
smsc_ece1099.txt
sparse.txt
spinlocks.txt
stable_api_nonsense.txt
stable_kernel_rules.txt	stable_kernel_rules: spelling/word usage	2014-04-16 14:13:26 -07:00
static-keys.txt
SubmitChecklist
SubmittingDrivers
SubmittingPatches	Documentation/SubmittingPatches: describe the Fixes: tag	2014-06-06 16:08:11 -07:00
svga.txt
sysfs-rules.txt
sysrq.txt
this_cpu_ops.txt
unaligned-memory-access.txt
unicode.txt
unshare.txt
vfio.txt
VGA-softcursor.txt
vgaarbiter.txt
video-output.txt
vme_api.txt
volatile-considered-harmful.txt
workqueue.txt
ww-mutex-design.txt
xz.txt
zorro.txt