linux/Documentation
Mel Gorman db9e5679d6 delay-accounting: reimplement -c for getdelays.c to report information on a target command
Task delay-accounting was identified as one means of determining how long
a process spends in congestion_wait() without adding new statistics.  For
example, if the workload should not be doing IO, delay-accounting could
reveal how long it was spending in unexpected IO or delays.
Unfortunately, on closer examination it was clear that getdelays does not
act as documented.

Commit a3baf649 ("per-task-delay-accounting: documentation") added
Documentation/accounting/getdelays.c with a -c switch that was documented
to fork/exec a child and report statistics on it but for reasons that are
unclear to me, commit 9e06d3f9 deleted support for this switch but did not
update the documentation.  It might be an oversight or it might be because
the control flow of the program meant that accounting information would be
printed once early in the lifetime of the program making it of limited
use.

This patch reimplements -c for getdelays.c to act as documented.  Unlike
the original version, it waits until the command completes before printing
any information on it.  An example of it being used looks like

$ ./getdelays -d -c find /home/mel -name mel
print delayacct stats ON
/home/mel
/home/mel/.notes-wine/drive_c/windows/profiles/mel
/home/mel/.wine/drive_c/windows/profiles/mel
/home/mel/git-configs/dot.kde/share/apps/konqueror/home/mel
PID	5923

CPU             count     real total  virtual total    delay total
                42779     5051232096     5164722692      564207988
IO              count    delay total
                41727    97804147758
SWAP            count    delay total
                    0              0
RECLAIM         count    delay total
                    0              0

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:17 -07:00
..
ABI Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86 2010-10-25 08:28:13 -07:00
accounting delay-accounting: reimplement -c for getdelays.c to report information on a target command 2010-10-27 18:03:17 -07:00
acpi ACPI: introduce module parameter acpi.aml_debug_output 2010-08-14 23:02:14 -04:00
aoe Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
arm Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-10-24 13:41:39 -07:00
auxdisplay includecheck fix: Documentation, cfag12864b-example.c 2009-09-24 07:20:57 -07:00
blackfin Blackfin: document SPI CS limitations with CPHA=0 2010-08-06 12:55:52 -04:00
block Merge branch 'v2.6.36-rc8' into for-2.6.37/barrier 2010-10-19 09:13:04 +02:00
blockdev Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
cdrom Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
cgroups cgroup: add clone_children control file 2010-10-27 18:03:09 -07:00
connector Documentation/: it's -> its where appropriate 2010-04-23 02:09:52 +02:00
console doc: fix console doc typo 2010-02-24 13:51:32 +01:00
cpu-freq [CPUFREQ] Processor Clocking Control interface driver 2010-01-13 10:55:16 -05:00
cpuidle
cris
crypto async_tx: add support for asynchronous RAID6 recovery operations 2009-08-29 19:09:27 -07:00
development-process Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
device-mapper Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
DocBook docbook: add idr/ida to kernel-api docbook 2010-10-26 17:40:56 -07:00
driver-model Fix spelling of 'platform' in comments and doc 2010-02-05 12:22:34 +01:00
dvb Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-08-04 15:31:02 -07:00
early-userspace
fault-injection lkdtm: add debugfs access and loosen KPROBE ties 2010-03-06 11:26:32 -08:00
fb Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
filesystems /proc/pid/pagemap: document in Documentation/filesystems/proc.txt 2010-10-27 18:03:13 -07:00
firmware_class firmware: Update hotplug script 2010-08-05 13:53:34 -07:00
frv
hwmon hwmon: LTC4261 Hardware monitoring driver 2010-10-25 14:11:20 -07:00
i2c i2c: Add support for custom probe function 2010-08-11 18:20:56 +02:00
i2o
ia64 Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
ide ide: preserve Host Protected Area by default (v2) 2009-06-07 13:52:52 +02:00
infiniband Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
input HID: ntrig: add documention 2010-08-30 15:25:18 +02:00
ioctl Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 2010-08-07 17:09:24 -07:00
isdn Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-08-04 15:31:02 -07:00
ja_JP Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
kbuild kbuild: drop unifdef-y support 2010-08-14 22:26:52 +02:00
kdump trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
ko_KR Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
kvm KVM: Document that KVM_GET_SUPPORTED_CPUID may return emulated values 2010-10-24 10:52:48 +02:00
laptops thinkpad-acpi: untangle ACPI/vendor backlight selection 2010-08-16 11:54:50 -04:00
lguest Merge branch 'v2.6.36-rc8' into for-2.6.37/barrier 2010-10-19 09:13:04 +02:00
m68k
make
mips ide: remove unused CONFIG_BLK_DEV_IDE_AU1XXX_SEQTS_PER_RQ 2009-01-14 19:19:03 +01:00
misc-devices Documentation: short descriptions for bh1770glc and apds990x drivers 2010-10-26 16:52:14 -07:00
mmc mmc: add erase, secure erase, trim and secure trim operations 2010-08-12 08:43:30 -07:00
mn10300 trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
mtd Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
namespaces
netlabel Documentation/: it's -> its where appropriate 2010-04-23 02:09:52 +02:00
networking can-raw: add msg_flags to distinguish local traffic 2010-10-21 04:27:03 -07:00
parisc
PCI Documentation: pci.txt: fix typo 2010-07-11 22:17:45 +02:00
pcmcia pcmcia: use autoconfiguration feature for ioports and iomem 2010-09-29 17:20:24 +02:00
power PM: Introduce library for device-specific OPPs (v7) 2010-10-17 01:57:50 +02:00
powerpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6 2010-10-22 20:30:48 -07:00
pps LinuxPPS: core support 2009-06-18 13:04:04 -07:00
prctl
RCU rcu: Add tracing data to support queueing models 2010-09-23 09:16:53 -07:00
s390 Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
scheduler sched: Remove USER_SCHED from documentation 2010-04-02 20:12:01 +02:00
scsi [SCSI] st: add MTWEOFI to write filemarks without flushing drive buffer 2010-10-08 17:16:22 -05:00
serial Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
sh sh: Kill off remaining CONFIG_SH_KGDB bits. 2008-12-22 18:44:05 +09:00
sound Merge branch 'topic/hda' into for-linus 2010-10-25 10:40:05 +02:00
sparc
spi spi/ep93xx: implemented driver for Cirrus EP93xx SPI controller 2010-05-25 00:23:16 -06:00
sysctl doc: clarify the behaviour of dirty_ratio/dirty_bytes 2010-10-27 18:03:08 -07:00
telephony Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
thermal thermal: add sanity check for the passive attribute 2009-11-05 18:18:10 -05:00
timers Documentation/timers/hpet_example.c: add supporting info for hpet_example 2010-10-26 16:52:11 -07:00
trace tracing, vmscan: add trace events for LRU list shrinking 2010-10-26 16:52:07 -07:00
uml Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
usb USB: teach "devices" file about Wireless and SuperSpeed USB 2010-10-22 10:21:40 -07:00
video4linux V4L/DVB: Documentation: add v4l2-controls.txt documenting the new controls API 2010-08-08 23:43:04 -03:00
vm mm: highmem documentation 2010-10-26 16:52:08 -07:00
w1 Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
watchdog watchdog: docs: add an entry for imx2_wdt 2010-07-01 16:02:55 +00:00
wimax i2400m: documentation and instructions for usage 2009-01-07 10:00:18 -08:00
x86 Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-22 08:54:21 -07:00
zh_CN Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
.gitignore add random binaries to .gitignore 2010-04-08 11:34:34 +02:00
00-INDEX mmc: add erase, secure erase, trim and secure trim operations 2010-08-12 08:43:30 -07:00
apparmor.txt AppArmor: update Maintainer and Documentation 2010-08-02 15:35:15 +10:00
applying-patches.txt
atomic_ops.txt Documentation/: it's -> its where appropriate 2010-04-23 02:09:52 +02:00
bad_memory.txt Document handling of bad memory 2008-12-03 16:09:53 -07:00
basic_profiling.txt
binfmt_misc.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
braille-console.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
bt8xxgpio.txt
btmrvl.txt Bluetooth: Add documentation for Marvell Bluetooth driver 2009-08-22 14:25:32 -07:00
BUG-HUNTING
bus-virt-phys-mapping.txt documentation: fix almost duplicate filenames (IO/io-mapping.txt) 2010-07-20 17:49:30 +00:00
cachetlb.txt Documentation/: it's -> its where appropriate 2010-04-23 02:09:52 +02:00
Changes Documentation update broken web addresses 2010-07-11 21:55:42 +02:00
circular-buffers.txt Document Linux's circular buffering capabilities 2010-03-24 16:31:22 -07:00
coccinelle.txt Documentation: fix ubuntu distro name 2010-06-29 15:27:00 +02:00
CodingStyle trivial: fix typo milisecond/millisecond for documentation and source comments. 2009-06-12 18:01:46 +02:00
cpu-hotplug.txt documentation: fix erroneous email address. 2010-08-11 23:04:10 +09:30
cpu-load.txt
cputopology.txt topology/sysfs: Provide book id and siblings attributes 2010-09-09 20:41:25 +02:00
credentials.txt CRED: Fix __task_cred()'s lockdep check and banner comment 2010-07-29 15:16:18 -07:00
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt ieee1394: update URLs in debugging-via-ohci1394.txt 2009-10-03 09:28:11 +02:00
dell_rbu.txt trivial: Documentation/dell_rbu.txt: fix typos 2009-06-12 18:01:50 +02:00
devices.txt Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6 2010-10-22 20:30:48 -07:00
DMA-API-HOWTO.txt Documentation: DMA-API-HOWTO.txt: rename ARCH_KMALLOC_MINALIGN to ARCH_DMA_MINALIGN 2010-08-14 11:56:46 -07:00
DMA-API.txt dma-mapping: remove dma_is_consistent API 2010-08-11 08:59:21 -07:00
DMA-attributes.txt
DMA-ISA-LPC.txt
dmaengine.txt async_tx, dmaengine: document channel allocation and api rework 2009-01-05 18:10:19 -07:00
dontdiff Merge branch 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-kconfig 2010-02-25 14:43:57 -08:00
dynamic-debug-howto.txt Dynamic Debug: Introduce ddebug_query= boot parameter 2010-10-22 10:16:42 -07:00
edac.txt Documentation/edac.txt: Reflect the sysfs changes at the document 2010-05-10 11:49:30 -03:00
eisa.txt doc: fix Defaultd -> Defaults typo in EISA doc 2010-02-05 12:22:39 +01:00
email-clients.txt Documentation/email-clients.txt: update gmail information 2010-03-12 15:52:35 -08:00
feature-removal-schedule.txt cgroup: notify ns_cgroup deprecated 2010-10-27 18:03:09 -07:00
flexible-arrays.txt Update flex_arrays.txt 2009-10-15 07:25:20 -06:00
futex-requeue-pi.txt futex: add requeue-pi documentation 2009-05-09 07:12:50 +02:00
gcov.txt trivial: fix typo in CONFIG_DEBUG_FS in gcov doc 2009-09-21 15:14:56 +02:00
gpio.txt gpio: doc updates 2010-09-09 18:57:24 -07:00
highuid.txt
HOWTO Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
hw_random.txt
init.txt init/main.c: improve usability in case of init binary failure 2010-03-06 11:26:29 -08:00
initrd.txt
intel_txt.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
Intel-IOMMU.txt intel-iommu: Kill DMAR_BROKEN_GFX_WA option. 2009-09-19 09:37:23 -07:00
io_ordering.txt
io-mapping.txt io mapping: improve documentation 2008-11-03 18:21:44 +01:00
iostats.txt
IPMI.txt ipmi: add parameter to limit CPU usage in kipmid 2010-03-12 15:52:39 -08:00
IRQ-affinity.txt
IRQ.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kernel-doc-nano-HOWTO.txt docbook: warn on unused doc entries 2010-09-11 16:49:21 -07:00
kernel-docs.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
kernel-parameters.txt Merge branch 'nfs-for-2.6.37' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6 2010-10-25 13:48:29 -07:00
keys-request-key.txt
keys.txt KEYS: Add a keyctl to install a process's session keyring on its parent [try #6] 2009-09-02 21:29:22 +10:00
kmemcheck.txt kmemcheck: update documentation 2009-07-01 22:36:22 +02:00
kmemleak.txt kmemleak: add clear command support 2009-09-08 16:36:08 +01:00
kobject.txt kobject: documentation: Update to refer to kset-example.c. 2010-03-19 07:12:20 -07:00
kprobes.txt kprobes: Update document about irq disabled state in kprobe handler 2010-10-14 08:55:27 +02:00
kref.txt kref: double kref_put() in my_data_handler() 2009-09-18 09:48:52 -07:00
ldm.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
leds-class.txt led: document sysfs interface 2009-08-28 15:21:12 -04:00
leds-lp3944.txt leds: LED driver for National Semiconductor LP3944 Funlight Chip 2009-06-23 20:21:38 +01:00
local_ops.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
lockdep-design.txt lockdep: Fix typos in documentation 2009-08-07 12:03:46 +02:00
lockstat.txt lockstat: Add usage info to Documentation/lockstat.txt 2009-12-06 13:20:02 +01:00
logo.gif Revert "linux.conf.au 2009: Tuz" 2009-04-27 12:00:27 -07:00
logo.txt Revert "linux.conf.au 2009: Tuz" 2009-04-27 12:00:27 -07:00
magic-number.txt documentation: update header file paths 2009-01-06 15:59:28 -08:00
Makefile Documentation/fs/: split txt and source files 2010-03-12 15:52:35 -08:00
ManagementStyle docs: fix ManagementStyle book name 2008-10-30 11:38:46 -07:00
mca.txt
md.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
memory-barriers.txt Document Linux's circular buffering capabilities 2010-03-24 16:31:22 -07:00
memory-hotplug.txt mm: add numa node symlink for memory section in sysfs 2009-12-15 08:53:17 -08:00
memory.txt Documentation/memory.txt: remove some very outdated recommendations 2009-09-22 07:17:26 -07:00
mono.txt
mutex-design.txt mutex: Fix annotations to include it in kernel-locking docbook 2010-09-03 08:19:51 +02:00
nmi_watchdog.txt x86, nmi-watchdog: update procfs nmi_watchdog file documentation v2 2008-10-30 19:07:04 +01:00
nommu-mmap.txt nommu: fix malloc performance by adding uninitialized flag 2009-12-15 08:53:24 -08:00
numastat.txt mm: fix NUMA accounting in numastat.txt 2009-09-22 07:17:39 -07:00
oops-tracing.txt panic: Add taint flag TAINT_FIRMWARE_WORKAROUND ('I') 2010-05-19 08:37:43 +01:00
padata.txt Documentation/padata.txt: fix typos etc. 2010-08-11 08:59:18 -07:00
parport-lowlevel.txt
parport.txt
pi-futex.txt
pnp.txt doc: capitalization and other minor fixes in pnp doc 2010-02-05 12:22:44 +01:00
preempt-locking.txt
printk-formats.txt DOC: add printk-formats.txt 2008-11-12 17:17:17 -08:00
prio_tree.txt
rbtree.txt rbtree: Add support for augmented rbtrees 2010-02-18 15:40:56 -08:00
rfkill.txt Document the rfkill sysfs ABI 2010-03-10 17:09:33 -05:00
robust-futex-ABI.txt futex: documentation: fix inconsistent description of futex list_op_pending 2009-06-18 13:03:56 -07:00
robust-futexes.txt
rt-mutex-design.txt variable name fix to Documentation/rt-mutex-design.txt 2010-06-05 17:39:09 +02:00
rt-mutex.txt
rtc.txt rtc: add boot_timesource sysfs attribute 2009-09-23 07:39:46 -07:00
SAK.txt
SecurityBugs
SELinux.txt
serial-console.txt
sgi-ioc4.txt
sgi-visws.txt
SM501.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
Smack.txt Documentation/: it's -> its where appropriate 2010-04-23 02:09:52 +02:00
sparse.txt update email address 2010-07-19 10:56:54 +02:00
spinlocks.txt Documentation: rw_lock lessons learned 2009-12-14 09:46:56 -08:00
stable_api_nonsense.txt
stable_kernel_rules.txt Documentation: -stable rules: upstream commit ID requirement reworded 2010-04-22 15:24:56 -07:00
SubmitChecklist Documentation: update SubmitChecklist for O=objdir and kconfig testing 2010-05-24 07:31:20 -07:00
SubmittingDrivers Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
SubmittingPatches SubmittingPatches: add more about patch descriptions 2010-08-09 20:45:05 -07:00
svga.txt
sysfs-rules.txt Fix typos in comments 2010-03-16 11:47:56 +01:00
sysrq.txt documentation: update sysrq.txt magic sysrq keys 2010-10-26 17:32:41 -07:00
tomoyo.txt TOMOYO: Update version to 2.3.0 2010-08-02 15:35:10 +10:00
unaligned-memory-access.txt
unicode.txt
unshare.txt
VGA-softcursor.txt
vgaarbiter.txt vgaarbiter: fix a typo in the vgaarbiter Documentation 2009-12-16 11:28:58 -08:00
video-output.txt
volatile-considered-harmful.txt Documentation/volatile-considered-harmful.txt: correct cpu_relax() documentation 2010-03-24 16:31:20 -07:00
workqueue.txt workqueue: add and use WQ_MEM_RECLAIM flag 2010-10-11 15:20:26 +02:00
zorro.txt