linux/Documentation
Sergey Senozhatsky 10447b60be zram: remove `num_migrated' device attr
This patch introduces rework to zram stats.  We have per-stat sysfs nodes,
and it makes things a bit hard to use in user space: it doesn't give an
immediate stats 'snapshot', it requires user space to use more syscalls -
open, read, close for every stat file, with appropriate error checks on
every step, etc.

First, zram now accounts block layer statistics, available in
/sys/block/zram<id>/stat and /proc/diskstats files.  So some new stats are
available (see Documentation/block/stat.txt), besides, zram's activities
now can be monitored by sysstat's iostat or similar tools.

Example:
cat /sys/block/zram0/stat
248     0    1984    0   251029     0  2008232   5120   0   5116   5116

Second, group currently exported on per-stat basis nodes into two
categories (files):

-- zram<id>/io_stat
accumulates device's IO stats, that are not accounted by block layer,
and contains:
        failed_reads
        failed_writes
        invalid_io
        notify_free

Example:
cat /sys/block/zram0/io_stat
0        0        0   652572

-- zram<id>/mm_stat
accumulates zram mm stats and contains:
        orig_data_size
        compr_data_size
        mem_used_total
        mem_limit
        mem_used_max
        zero_pages
        num_migrated

Example:
cat /sys/block/zram0/mm_stat
434634752 270288572 279158784        0 579895296    15060        0

per-stat sysfs nodes are now considered to be deprecated and we plan to
remove them (and clean up some of the existing stat code) in two years (as
of now, there is no warning printed to syslog about deprecated stats being
used).  User space is advised to use the above mentioned 3 files.

This patch (of 7):

Remove sysfs `num_migrated' attribute.  We are moving away from per-stat
device attrs towards 3 stat files that will accumulate io and mm stats in
a format similar to block layer statistics in /sys/block/<dev>/stat.  That
will be easier to use in user space, and reduce the number of syscalls
needed to read zram device statistics.

`num_migrated' will return back in zram<id>/mm_stat file.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:21 -07:00
..
ABI zram: remove `num_migrated' device attr 2015-04-15 16:35:21 -07:00
accounting Documentation: use subdir-y to avoid unnecessary built-in.o files 2014-09-26 11:02:55 +02:00
acpi Power management and ACPI updates for v4.1-rc1 2015-04-14 20:21:54 -07:00
aoe
arm ARM: SoC platform changes 2015-02-17 09:27:54 -08:00
arm64 arm64: Emulate SETEND for AArch32 tasks 2015-01-23 17:11:44 +00:00
auxdisplay Documentation: use subdir-y to avoid unnecessary built-in.o files 2014-09-26 11:02:55 +02:00
backlight
blackfin Documentation: fix blackfin gptimers-example build errors 2015-01-28 12:07:58 -07:00
block Merge branch 'for-3.19/core' of git://git.kernel.dk/linux-block 2014-12-13 14:14:23 -08:00
blockdev zram: report maximum used memory 2014-10-09 22:26:02 -04:00
bus-devices
cdrom
cgroups Merge branch 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2015-04-13 16:47:11 -07:00
cma cma: debug: document new debugfs interface 2015-04-14 16:49:00 -07:00
connector w1: optional bundling of netlink kernel replies 2014-05-27 13:56:21 -07:00
console
cpu-freq intel_pstate: Add num_pstates to sysfs 2015-01-30 01:52:17 +01:00
cpuidle
cris
crypto crypto: doc - userspace interface spec 2014-11-13 22:31:38 +08:00
development-process Documentation: remove outdated references to the linux-next wiki 2014-10-28 09:06:11 -04:00
device-mapper dm crypt: add 'submit_from_crypt_cpus' option 2015-02-16 11:11:15 -05:00
devicetree Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-04-15 09:00:47 -07:00
dmaengine Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2015-02-18 08:49:20 -08:00
DocBook KGDB/KDB New: 2015-02-20 15:13:29 -08:00
driver-model Staging drivers patches for 3.20-rc1 2015-02-15 11:30:39 -08:00
dvb [media] get_dvb_firmware: Update firmware of ITEtech IT9135 2014-09-21 17:03:04 -03:00
early-userspace
EDID drm: Add 800x600 (SVGA) screen resolution to the built-in EDIDs 2014-05-26 12:53:40 +10:00
extcon
fault-injection
fb doc: spelling error changes 2014-05-05 15:32:05 +02:00
filesystems mm: new pfn_mkwrite same as page_mkwrite for VM_PFNMAP 2015-04-15 16:35:20 -07:00
firmware_class doc: fix minor typos in firmware_class README 2014-07-17 18:43:40 -07:00
fmc
frv
gpio gpio: board.txt: Fix the gpio name example 2015-01-28 11:14:00 -07:00
hid HID: sensor: Update document for custom sensor 2015-04-10 22:22:56 +02:00
hwmon hwmon: (it87) Add support for IT8620E 2015-04-05 06:01:00 -07:00
i2c i2c: slave: add documentation for i2c-slave-eeprom 2015-03-27 16:53:39 +01:00
i2o
ia64 virtual: Documentation: simplify and generalize paravirt_ops.txt 2015-02-13 17:15:44 +10:30
ide
infiniband IB/mad: add new ioctl to ABI to support new registration options 2014-08-10 20:36:00 -07:00
input Input: alps - document stick behavior for protocol V2 2015-04-05 11:48:35 -07:00
ioctl cxl: Add documentation for userspace APIs 2014-10-08 20:16:19 +11:00
isdn
ja_JP Documentation: Update stable address in Chinese and Japanese translations 2014-04-16 14:13:27 -07:00
kbuild Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2015-02-19 10:31:37 -08:00
kdump kernel: add panic_on_warn 2014-12-10 17:41:10 -08:00
ko_KR
laptops Documentation: update .gitignore files 2014-09-26 11:02:59 +02:00
leds
locking Documentation changes for 3.20 2015-02-11 13:03:11 -08:00
m68k
memory-devices
metag
mic Documentation: Build mic/mpssd only for x86_64 2014-12-05 11:18:36 -05:00
mips Documentation: au1xxx-ide.c has moved 2014-08-26 09:35:53 +02:00
misc-devices Documentation/misc-devices/mei: Fix indentation of embedded code. 2015-01-29 12:56:20 -07:00
mmc
mn10300
mtd MTD updates for 3.16: 2014-06-11 08:35:34 -07:00
namespaces
netlabel
networking Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-04-14 15:44:14 -04:00
nfc
nios2 Documentation: Add documentation for Nios2 architecture 2014-12-08 12:56:06 +08:00
parisc
PCI PCI: Clarify policy for vendor IDs in pci.txt 2015-04-09 13:34:02 -05:00
pcmcia Documentation: use subdir-y to avoid unnecessary built-in.o files 2014-09-26 11:02:55 +02:00
phy
platform Documentation: Add list of laptop models supported by the Compal driver 2014-06-10 19:11:06 -04:00
power Power management and ACPI updates for v4.1-rc1 2015-04-14 20:21:54 -07:00
powerpc cxl: Add documentation for userspace APIs 2014-10-08 20:16:19 +11:00
pps
prctl Documentation: Restrict TSC test code to x86 2014-10-28 08:46:27 -04:00
pti
ptp ptp: restore the makefile for building the test program. 2014-10-24 16:07:10 -04:00
rapidio rapidio/tsi721_dma: rework scatter-gather list handling 2014-08-08 15:57:24 -07:00
RCU Merge branches 'doc.2015.01.07a', 'fixes.2015.01.15a', 'preempt.2015.01.06a', 'srcu.2015.01.06a', 'stall.2015.01.16a' and 'torture.2015.01.11a' into HEAD 2015-01-15 23:34:34 -08:00
s390 s390/docs: Remove section about script debugging from Debugging390.txt 2015-01-15 11:11:14 +01:00
scheduler doc: brief user documentation for completion 2015-01-30 11:19:25 -07:00
scsi genirq: Remove the deprecated 'IRQF_DISABLED' request_irq() flag entirely 2015-03-05 20:53:06 +01:00
security KEYS: Make /proc/keys unconditional if CONFIG_KEYS=y 2015-01-22 22:34:32 +00:00
serial serial: Fix locking for uart driver set_termios() method 2014-11-05 18:53:54 -08:00
sh
sound ALSA: hda - Add "eapd" model string for AD1986A codec 2014-12-10 14:00:13 +01:00
spi Merge remote-tracking branches 'spi/topic/spidev' and 'spi/topic/spidev-test' into spi-next 2015-04-11 23:09:31 +01:00
sysctl mm: allow compaction of unevictable pages 2015-04-15 16:35:17 -07:00
target Documentation/target: Update fabric_ops to latest code 2015-01-06 13:46:49 -08:00
thermal Documentation: thermal: document of_cpufreq_cooling_register() 2015-01-06 14:39:17 -04:00
timers documentation: Update NO_HZ_FULL interaction with POSIX timers 2015-02-26 11:57:29 -08:00
tpm
trace Char / Misc patches for 3.20-rc1 2015-02-15 10:48:44 -08:00
usb usb: patches for v4.1 merge window 2015-03-24 22:57:49 +01:00
vDSO vdso: don't require 64-bit math in standalone test 2014-10-25 10:53:44 -04:00
video4linux MODULE_DEVICE_TABLE: fix some callsites 2015-02-13 21:21:40 -08:00
virtual Features and fixes for 4.1 (kvm/next) 2015-04-07 18:10:03 +02:00
vm zsmalloc: zsmalloc documentation 2015-04-15 16:35:21 -07:00
w1 w1: new w1_ds2406 driver 2014-06-19 17:45:14 -07:00
watchdog Documentation: use subdir-y to avoid unnecessary built-in.o files 2014-09-26 11:02:55 +02:00
wimax
x86 x86/mm/KASLR: Propagate KASLR status to kernel proper 2015-04-03 15:26:15 +02:00
xtensa
zh_CN Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2014-08-06 21:03:53 -07:00
00-INDEX Update of Documentation/dmaengine/00-INDEX 2014-12-29 15:28:24 -07:00
applying-patches.txt Documentation: change "&" to "and" in Documentation/applying-patches.txt 2014-09-26 11:10:11 +02:00
assoc_array.txt
atomic_ops.txt documentation: Clarify memory-barrier semantics of atomic operations 2015-02-26 11:57:31 -08:00
bad_memory.txt
basic_profiling.txt
bcache.txt
binfmt_misc.txt binfmt_misc: touch up documentation a bit 2014-10-14 02:18:16 +02:00
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
BUG-HUNTING
bus-virt-phys-mapping.txt
cachetlb.txt rmap: drop support of non-linear mappings 2015-02-10 14:30:31 -08:00
Changes Documentation: GNU is frequently spelled Gnu 2014-12-29 15:33:17 -07:00
circular-buffers.txt
clk.txt clk: Add rate constraints to clocks 2015-02-02 14:23:42 -08:00
coccinelle.txt
CodeOfConflict Code of Conflict 2015-02-27 11:44:24 -08:00
CodingStyle CodingStyle: enable emacs display of trailing whitespace 2015-01-28 12:05:46 -07:00
cpu-hotplug.txt Doc/cpu-hotplug: Specify race-free way to register CPU hotplug callbacks 2014-03-20 13:43:40 +01:00
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 Documentation: correct parameter error for dma_mapping_error 2014-09-26 11:22:29 +02:00
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 Documentation/dma-buf-sharing.txt: update API descriptions 2014-08-28 11:57:24 +05:30
DMA-ISA-LPC.txt DMA-API: Clarify physical/bus address distinction 2014-05-20 16:54:21 -06:00
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/email-clients.txt: add info about Claws Mail 2014-12-02 11:55:29 -05:00
flexible-arrays.txt
futex-requeue-pi.txt doc: Fix misnamed FUTEX_CMP_REQUEUE_PI op constants 2015-01-19 12:05:32 +01:00
gcov.txt
gdb-kernel-debugging.txt scripts/gdb: add basic documentation 2015-02-17 14:34:54 -08:00
highuid.txt
HOWTO Documentation: remove outdated references to the linux-next wiki 2014-10-28 09:06:11 -04:00
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_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt
iostats.txt
IPMI.txt ipmi: Add SMBus interface driver (SSIF) 2014-12-11 15:04:11 -06:00
IRQ-affinity.txt
IRQ-domain.txt irqdomain: Introduce new interfaces to support hierarchy irqdomains 2014-11-23 13:01:45 +01:00
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
kasan.txt kasan: enable instrumentation of global variables 2015-02-13 21:21:42 -08:00
kernel-doc-nano-HOWTO.txt
kernel-docs.txt
kernel-parameters.txt Power management and ACPI updates for v4.1-rc1 2015-04-14 20:21:54 -07:00
kernel-per-CPU-kthreads.txt documentation: Update per-CPU kthreads documentation 2015-02-26 11:57:30 -08:00
kmemcheck.txt doc: fix double words 2014-03-21 13:16:58 +01:00
kmemleak.txt Documentation: Add CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF case 2014-10-24 13:59:03 -04:00
kobject.txt kobject: grammar fix 2014-12-08 09:07:11 -05:00
kprobes.txt Documentation: add description for FTRACE probe status 2015-02-04 16:05:44 -05:00
kref.txt
kselftest.txt kselftest: Move the docs to the Documentation dir 2014-11-24 10:49:54 -07:00
ldm.txt
local_ops.txt percpu: update local_ops.txt to reflect this_cpu operations 2014-12-13 12:42:53 -08:00
lockup-watchdogs.txt lockup-watchdogs: Fix a typo 2014-08-26 09:35:52 +02:00
logo.gif
logo.txt
lzo.txt Documentation: lzo: document part of the encoding 2014-09-28 11:08:00 +02:00
magic-number.txt Documentation/serial: Delete obsolete driver documentation 2014-04-16 14:20:34 -07:00
mailbox.txt Documentation: Fix a typo in mailbox.txt 2014-11-03 11:54:50 -05:00
Makefile Documentation: add makefiles for more targets 2014-09-26 11:02:56 +02:00
ManagementStyle
md.txt
media-framework.txt
memory-barriers.txt documentation: Clarify control-dependency pairing 2015-02-26 11:57:32 -08:00
memory-hotplug.txt memory-hotplug: add sysfs valid_zones attribute 2014-10-09 22:25:52 -04:00
module-signing.txt Nothing major: the stricter permissions checking for sysfs broke 2014-04-06 09:38:07 -07:00
mono.txt
nommu-mmap.txt fs: introduce f_op->mmap_capabilities for nommu mmap support 2015-01-20 14:02:58 -07:00
numastat.txt
oops-tracing.txt livepatch: kernel: add TAINT_LIVEPATCH 2014-12-22 15:40:48 +01:00
padata.txt
parport-lowlevel.txt
parport.txt
percpu-rw-semaphore.txt
phy.txt phy: improved lookup method 2014-11-21 19:48:50 +05:30
pi-futex.txt
pinctrl.txt pinctrl: fix example .get_group_pins implementation signature 2015-03-18 02:02:20 +01:00
pnp.txt
preempt-locking.txt
printk-formats.txt lib/vsprintf: add %*pE[achnops] format specifier 2014-10-14 02:18:26 +02:00
pwm.txt pwm: modify PWM_LOOKUP to initialize all struct pwm_lookup members 2014-05-21 11:19:36 +02:00
ramoops.txt pstore-ram: Allow optional mapping with pgprot_noncached 2014-12-11 13:38:31 -08:00
rbtree.txt doc: spelling error changes 2014-05-05 15:32:05 +02:00
remoteproc.txt
rfkill.txt rfkill: document rfkill module parameters 2015-01-09 23:22:12 +01:00
robust-futex-ABI.txt
robust-futexes.txt doc: spelling error changes 2014-05-05 15:32:05 +02:00
rpmsg.txt
rtc.txt Documentation, split up rtc.txt into documentation and test file 2015-03-24 22:01:58 -06:00
SAK.txt
SecurityBugs
serial-console.txt
sgi-ioc4.txt
SM501.txt
smsc_ece1099.txt
sparse.txt
stable_api_nonsense.txt
stable_kernel_rules.txt stable_kernel_rules: Add clause about specification of kernel versions to patch. 2015-03-26 23:52:24 +01:00
static-keys.txt
SubmitChecklist
SubmittingDrivers doc: SubmittingPatches: remove dead link, kerneltrap.org no longer works 2014-06-19 15:15:27 +02:00
SubmittingPatches Merge branch 'doc/sp-update' into docs-next 2015-01-29 13:11:58 -07:00
svga.txt
sysfs-rules.txt Documentation/sysfs-rules.txt: Add device attribute error code documentation 2014-09-19 14:44:51 -07:00
sysrq.txt
this_cpu_ops.txt Docs: this_cpu_ops: remove redundant add forms 2014-09-26 11:03:00 +02:00
unaligned-memory-access.txt
unicode.txt
unshare.txt
vfio.txt drivers/vfio: EEH support for VFIO PCI device 2014-08-05 15:28:48 +10:00
VGA-softcursor.txt
vgaarbiter.txt
video-output.txt
vme_api.txt
volatile-considered-harmful.txt
workqueue.txt
xillybus.txt xillybus: Move out of staging 2014-09-23 23:44:16 -07:00
xz.txt
zorro.txt