linux/Documentation
Peter Oberparleiter 2521f2c228 gcov: add gcov profiling infrastructure
Enable the use of GCC's coverage testing tool gcov [1] with the Linux
kernel.  gcov may be useful for:

 * debugging (has this code been reached at all?)
 * test improvement (how do I change my test to cover these lines?)
 * minimizing kernel configurations (do I need this option if the
   associated code is never run?)

The profiling patch incorporates the following changes:

 * change kbuild to include profiling flags
 * provide functions needed by profiling code
 * present profiling data as files in debugfs

Note that on some architectures, enabling gcc's profiling option
"-fprofile-arcs" for the entire kernel may trigger compile/link/
run-time problems, some of which are caused by toolchain bugs and
others which require adjustment of architecture code.

For this reason profiling the entire kernel is initially restricted
to those architectures for which it is known to work without changes.
This restriction can be lifted once an architecture has been tested
and found compatible with gcc's profiling. Profiling of single files
or directories is still available on all platforms (see config help
text).

[1] http://gcc.gnu.org/onlinedocs/gcc/Gcov.html

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:03:57 -07:00
..
ABI Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block 2009-06-11 11:10:35 -07:00
accounting Documentation/accounting/getdelays.c intialize the variable before using it 2009-06-16 19:47:51 -07:00
acpi ACPI: update debug parameter documentation 2008-11-07 21:45:29 -05:00
aoe
arm [ARM] S3C24XX: GPIO: Change to macros for GPIO numbering 2009-05-18 16:26:03 +01:00
auxdisplay .gitignore updates 2008-10-30 11:38:45 -07:00
blackfin Blackfin arch: Add document about bfin-gpio 2009-01-07 23:14:38 +08:00
block trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
blockdev mflash: initial support 2009-04-07 08:12:38 +02:00
cdrom debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem. 2009-06-15 21:30:28 -07:00
cgroups memcg: add interface to reset limits 2009-06-18 13:03:48 -07:00
connector Documentation/connector/cn_test.c comment unused cn_test_want_notify() 2009-06-18 13:03:46 -07:00
console
cpu-freq [CPUFREQ] minor correction to cpu-freq documentation 2009-06-15 11:49:42 -04:00
cpuidle
cris fix random typos 2008-10-16 11:21:30 -07:00
crypto async_tx, dmaengine: document channel allocation and api rework 2009-01-05 18:10:19 -07:00
development-process docs: Encourage better changelogs in the development process document 2009-06-04 10:32:49 -06:00
device-mapper
DocBook debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem. 2009-06-15 21:30:28 -07:00
driver-model Driver Core: Warn driver authors about adding device attributes 2009-06-15 21:30:23 -07:00
dvb V4L/DVB (11962): dvb: Fix broken link in get_dvb_firmware for nxt2004 (A180) 2009-06-16 19:07:39 -03:00
early-userspace
fault-injection debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem. 2009-06-15 21:30:28 -07:00
fb Documentation/fb/vesafb.txt: fix typo 2009-06-16 19:47:58 -07:00
filesystems isofs: let mode and dmode mount options override rock ridge mode setting 2009-06-18 13:03:45 -07:00
firmware_class driver core: fix documentation of request_firmware_nowait 2009-06-15 21:30:24 -07:00
frv
hwmon hwmon: (f71882fg) Add support for the F71858F 2009-06-15 18:39:52 +02:00
i2c i2c-viapro: Add new PCI device ID for VX855 2009-06-15 18:01:49 +02:00
i2o
ia64 trivial: Fix misspelling of firmware 2009-03-30 15:21:59 +02:00
ide ide: preserve Host Protected Area by default (v2) 2009-06-07 13:52:52 +02:00
infiniband IPoIB: Document newish features 2009-04-08 13:52:01 -07:00
input Input: multitouch - augment event semantics documentation 2009-05-23 09:53:26 -07:00
ioctl V4L/DVB (10870a): remove all references for video_decoder.h 2009-03-30 12:43:15 -03:00
isdn isdn: extend INTERFACE.CAPI document 2009-06-08 00:45:52 -07:00
ja_JP Sync patch for jp_JP/stable_kernel_rules.txt 2009-01-28 15:55:48 -08:00
kbuild kconfig: resort the documentation of the environment variables 2009-06-09 22:37:47 +02:00
kdump trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
ko_KR
laptops trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
lguest lguest: add support for indirect ring entries 2009-06-12 22:27:13 +09:30
m68k
make
mips ide: remove unused CONFIG_BLK_DEV_IDE_AU1XXX_SEQTS_PER_RQ 2009-01-14 19:19:03 +01:00
misc-devices drivers/misc/isl29003.c: driver for the ISL29003 ambient light sensor 2009-04-01 08:59:18 -07:00
mn10300 trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
mtd trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
namespaces
netlabel
networking Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6 2009-06-15 03:02:23 -07:00
parisc
PCI PCI MSI: Add example request loop to MSI-HOWTO.txt 2009-03-20 11:35:04 -07:00
pcmcia .gitignore updates 2008-10-30 11:38:45 -07:00
power Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2009-06-14 13:46:25 -07:00
powerpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-06-15 09:40:05 -07:00
prctl
RCU trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
s390 trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
scheduler trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
scsi Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6 2009-06-17 09:50:44 -07:00
serial Create/use more directory structure in the Documentation/ tree. 2008-11-14 17:28:53 +00:00
sh sh: Kill off remaining CONFIG_SH_KGDB bits. 2008-12-22 18:44:05 +09:00
sound Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2009-06-14 13:46:25 -07:00
sparc sparc: Remove Documentation/sparc/sbus_drivers.txt 2008-08-29 02:15:25 -07:00
spi spi: documentation: emphasise spi_master.setup() semantics 2009-04-21 13:41:50 -07:00
sysctl vmscan: properly account for the number of page cache pages zone_reclaim() can reclaim 2009-06-16 19:47:45 -07:00
telephony remove mention of CONFIG_KMOD from documentation 2008-07-22 19:24:29 +10:00
thermal
timers trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
trace debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem. 2009-06-15 21:30:28 -07:00
uml
usb trivial: usb: fix missing space typo in doc 2009-06-12 18:01:51 +02:00
video4linux V4L/DVB (11996): saa7134: add support for AVerMedia M103 (f736) 2009-06-16 19:07:53 -03:00
vm Documentation/vm/Makefile: don't try to build slqbinfo 2009-06-17 09:45:46 -07:00
w1 w1: send status messages after command processing 2009-01-08 08:31:14 -08:00
watchdog .gitignore updates 2008-10-30 11:38:45 -07:00
wimax i2400m: documentation and instructions for usage 2009-01-07 10:00:18 -08:00
x86 Merge branch 'linus' into x86/mce3 2009-06-11 23:31:52 +02:00
zh_CN
00-INDEX trivial: fix where cgroup documentation is not correctly referred to 2009-03-30 15:22:02 +02:00
applying-patches.txt
atomic_ops.txt Documentation/atomic_ops.txt: fix sample code 2009-06-16 19:47:52 -07:00
bad_memory.txt Document handling of bad memory 2008-12-03 16:09:53 -07:00
basic_profiling.txt
binfmt_misc.txt
braille-console.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
bt8xxgpio.txt gpio: add bt8xxgpio driver 2008-07-25 10:53:30 -07:00
BUG-HUNTING
c2port.txt Add c2 port support 2008-11-12 17:17:18 -08:00
cachetlb.txt
Changes Documentation/Changes: perl is needed to build the kernel 2009-06-18 13:03:46 -07:00
CodingStyle trivial: fix typo milisecond/millisecond for documentation and source comments. 2009-06-12 18:01:46 +02:00
cpu-hotplug.txt x86: use possible_cpus=NUM to extend the possible cpus allowed 2008-12-18 12:08:05 +01:00
cpu-load.txt
cputopology.txt cpumask: Use topology_core_cpumask()/topology_thread_cpumask() 2009-01-11 19:12:49 +01:00
credentials.txt CRED: Documentation 2008-11-14 10:39:26 +11:00
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt trivial: Documentation/dell_rbu.txt: fix typos 2009-06-12 18:01:50 +02:00
devices.txt lanana: assign a device name and numbering for MAX3100 2009-04-07 08:44:05 -07:00
DMA-API.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
DMA-attributes.txt powerpc/cell: Add DMA_ATTR_WEAK_ORDERING dma attribute and use in Cell IOMMU code 2008-07-22 10:39:36 +10:00
DMA-ISA-LPC.txt
DMA-mapping.txt dma-mapping: update the old macro DMA_nBIT_MASK related documentations 2009-04-07 08:31:12 -07:00
dmaengine.txt async_tx, dmaengine: document channel allocation and api rework 2009-01-05 18:10:19 -07:00
dontdiff dontdiff: Fix asm exclude 2009-03-26 15:45:43 -07:00
dynamic-debug-howto.txt Dynamic debug: allow simple quoting of words 2009-03-24 16:38:27 -07:00
edac.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
eisa.txt
email-clients.txt Documentation/email-clients.txt: add some info about gmail 2008-11-06 15:41:19 -08:00
exception.txt
feature-removal-schedule.txt irqs: add IRQF_SAMPLE_RANDOM to the feature-removal-schedule.txt (deprecated) list 2009-06-18 13:03:40 -07:00
futex-requeue-pi.txt futex: add requeue-pi documentation 2009-05-09 07:12:50 +02:00
gcov.txt gcov: add gcov profiling infrastructure 2009-06-18 13:03:57 -07:00
gpio.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
highuid.txt
HOWTO Remove Andrew Morton's http://www.zip.com.au/~akpm/ 2008-10-16 11:21:32 -07:00
hw_random.txt
ics932s401 ics932s401: new clock generator chip driver 2008-11-12 17:17:18 -08:00
initrd.txt
Intel-IOMMU.txt Documentation cleanup: trivial misspelling, punctuation, and grammar corrections. 2008-07-26 12:00:06 -07:00
io-mapping.txt io mapping: improve documentation 2008-11-03 18:21:44 +01:00
IO-mapping.txt Documentation: move DMA-mapping.txt to Doc/PCI/ 2009-01-29 18:19:29 -08:00
io_ordering.txt
iostats.txt Documentation cleanup: trivial misspelling, punctuation, and grammar corrections. 2008-07-26 12:00:06 -07:00
IPMI.txt
IRQ-affinity.txt genirq: Expose default irq affinity mask (take 3) 2008-06-05 15:18:30 +02:00
IRQ.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kernel-doc-nano-HOWTO.txt kernel-doc: restrict syntax for private: and public: 2009-05-02 15:36:10 -07:00
kernel-docs.txt doc: update to URL and status of kernel-docs.txt entry 2008-06-06 11:29:10 -07:00
kernel-parameters.txt gcov: add gcov profiling infrastructure 2009-06-18 13:03:57 -07:00
keys-request-key.txt
keys.txt Documentation cleanup: trivial misspelling, punctuation, and grammar corrections. 2008-07-26 12:00:06 -07:00
kmemcheck.txt kmemcheck: add the kmemcheck documentation 2009-06-13 14:27:20 +02:00
kmemleak.txt kmemleak: Add documentation on the memory leak detector 2009-06-11 17:03:29 +01:00
kobject.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
kprobes.txt debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem. 2009-06-15 21:30:28 -07:00
kref.txt
ldm.txt
leds-class.txt Documentation cleanup: trivial misspelling, punctuation, and grammar corrections. 2008-07-26 12:00:06 -07:00
local_ops.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
lockdep-design.txt locking: Documentation: lockdep-design.txt, fix note of state bits 2009-04-26 18:21:24 +02:00
lockstat.txt lockstat: contend with points 2008-10-20 15:43:10 +02:00
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 docsrc: build Documentation/ sources 2008-08-12 16:07:30 -07:00
ManagementStyle docs: fix ManagementStyle book name 2008-10-30 11:38:46 -07:00
markers.txt markers: comment marker_synchronize_unregister() on data dependency 2008-11-28 16:47:41 +01:00
mca.txt
md.txt Documentation/md.txt update 2009-03-31 15:18:37 +11:00
memory-barriers.txt sched: Document memory barriers implied by sleep/wake-up primitives 2009-04-29 14:15:55 +02:00
memory-hotplug.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
memory.txt
mono.txt
mutex-design.txt
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: Make mmap allocation page trimming behaviour configurable. 2009-01-08 12:04:47 +00:00
numastat.txt
oops-tracing.txt
parport-lowlevel.txt
parport.txt
pi-futex.txt
pnp.txt
preempt-locking.txt
printk-formats.txt DOC: add printk-formats.txt 2008-11-12 17:17:17 -08:00
prio_tree.txt
rbtree.txt trivial: rbtree.txt: fix rb_entry() parameters in sample code 2009-06-12 18:01:47 +02:00
rfkill.txt rfkill: document /dev/rfkill 2009-06-03 14:06:15 -04:00
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
rt-mutex.txt
rtc.txt
SAK.txt Remove Andrew Morton's old email accounts 2008-10-16 11:21:32 -07:00
SecurityBugs
SELinux.txt selinux: add support for installing a dummy policy (v2) 2008-08-27 08:54:08 +10:00
serial-console.txt
sgi-ioc4.txt
sgi-visws.txt
slow-work.txt Document the slow work thread pool 2009-04-03 16:42:35 +01:00
SM501.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
Smack.txt smack: implement logging V3 2009-04-14 09:00:23 +10:00
sparse.txt Documentation: explain the difference between __bitwise and __bitwise__ 2009-04-11 08:18:11 +02:00
spinlocks.txt
stable_api_nonsense.txt
stable_kernel_rules.txt Update stable tree documentation 2008-10-29 15:03:49 -07:00
SubmitChecklist documentation: explain memory barriers 2008-10-16 11:21:32 -07:00
SubmittingDrivers Remove Andrew Morton's old email accounts 2008-10-16 11:21:32 -07:00
SubmittingPatches Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2009-06-14 13:46:25 -07:00
svga.txt
sysfs-rules.txt Doc/sysfs-rules: Swap the order of the words so the sentence makes more sense 2009-05-08 19:22:20 -07:00
sysrq.txt Merge branch 'tracing/core-v2' into tracing-for-linus 2009-04-02 00:49:02 +02:00
tomoyo.txt tomoyo: add Documentation/tomoyo.txt 2009-04-14 09:14:58 +10:00
unaligned-memory-access.txt introduce HAVE_EFFICIENT_UNALIGNED_ACCESS Kconfig symbol 2008-07-25 10:53:27 -07:00
unicode.txt
unshare.txt
VGA-softcursor.txt
video-output.txt
volatile-considered-harmful.txt Documentation cleanup: trivial misspelling, punctuation, and grammar corrections. 2008-07-26 12:00:06 -07:00
voyager.txt
zorro.txt