linux.git/Documentation/kernel-parameters.txt, branch v3.19-rc2

Merge tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2014-12-19T04:28:33+00:00

Pull more ACPI and power management updates from Rafael Wysocki:
 "These are regression fixes (leds-gpio, ACPI backlight driver,
  operating performance points library, ACPI device enumeration
  messages, cpupower tool), other bug fixes (ACPI EC driver, ACPI device
  PM), some cleanups in the operating performance points (OPP)
  framework, continuation of CONFIG_PM_RUNTIME elimination, a couple of
  minor intel_pstate driver changes, a new MAINTAINERS entry for it and
  an ACPI fan driver change needed for better support of thermal
  management in user space.

  Specifics:

   - Fix a regression in leds-gpio introduced by a recent commit that
     inadvertently changed the name of one of the properties used by the
     driver (Fabio Estevam).

   - Fix a regression in the ACPI backlight driver introduced by a
     recent fix that missed one special case that had to be taken into
     account (Aaron Lu).

   - Drop the level of some new kernel messages from the ACPI core
     introduced by a recent commit to KERN_DEBUG which they should have
     used from the start and drop some other unuseful KERN_ERR messages
     printed by ACPI (Rafael J Wysocki).

   - Revert an incorrect commit modifying the cpupower tool (Prarit
     Bhargava).

   - Fix two regressions introduced by recent commits in the OPP library
     and clean up some existing minor issues in that code (Viresh
     Kumar).

   - Continue to replace CONFIG_PM_RUNTIME with CONFIG_PM throughout the
     tree (or drop it where that can be done) in order to make it
     possible to eliminate CONFIG_PM_RUNTIME (Rafael J Wysocki, Ulf
     Hansson, Ludovic Desroches).

     There will be one more "CONFIG_PM_RUNTIME removal" batch after this
     one, because some new uses of it have been introduced during the
     current merge window, but that should be sufficient to finally get
     rid of it.

   - Make the ACPI EC driver more robust against race conditions related
     to GPE handler installation failures (Lv Zheng).

   - Prevent the ACPI device PM core code from attempting to disable
     GPEs that it has not enabled which confuses ACPICA and makes it
     report errors unnecessarily (Rafael J Wysocki).

   - Add a "force" command line switch to the intel_pstate driver to
     make it possible to override the blacklisting of some systems in
     that driver if needed (Ethan Zhao).

   - Improve intel_pstate code documentation and add a MAINTAINERS entry
     for it (Kristen Carlson Accardi).

   - Make the ACPI fan driver create cooling device interfaces witn
     names that reflect the IDs of the ACPI device objects they are
     associated with, except for "generic" ACPI fans (PNP ID "PNP0C0B").

     That's necessary for user space thermal management tools to be able
     to connect the fans with the parts of the system they are supposed
     to be cooling properly.  From Srinivas Pandruvada"

* tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
  MAINTAINERS: add entry for intel_pstate
  ACPI / video: update the skip case for acpi_video_device_in_dod()
  power / PM: Eliminate CONFIG_PM_RUNTIME
  NFC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  SCSI / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / EC: Fix unexpected ec_remove_handlers() invocations
  Revert "tools: cpupower: fix return checks for sysfs_get_idlestate_count()"
  tracing / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  x86 / PM: Replace CONFIG_PM_RUNTIME in io_apic.c
  PM: Remove the SET_PM_RUNTIME_PM_OPS() macro
  mmc: atmel-mci: use SET_RUNTIME_PM_OPS() macro
  PM / Kconfig: Replace PM_RUNTIME with PM in dependencies
  ARM / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  sound / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  phy / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  video / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  tty / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  spi: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / PM: Do not disable wakeup GPEs that have not been enabled
  ACPI / utils: Drop error messages from acpi_evaluate_reference()
  ...

Merge branches 'pm-opp', 'pm-cpufreq' and 'pm-tools'

2014-12-18T17:44:53+00:00

* pm-opp:
  PM / OPP: do error handling at the bottom of dev_pm_opp_add_dynamic()
  PM / OPP: handle allocation of device_opp in a separate routine
  PM / OPP: reuse find_device_opp() instead of duplicating code
  PM / OPP: Staticize __dev_pm_opp_remove()
  PM / OPP: replace kfree with kfree_rcu while freeing 'struct device_opp'

* pm-cpufreq:
  MAINTAINERS: add entry for intel_pstate
  intel_pstate: Add a few comments
  intel_pstate: add kernel parameter to force loading

* pm-tools:
  Revert "tools: cpupower: fix return checks for sysfs_get_idlestate_count()"

Merge tag 'trace-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2014-12-16T20:53:59+00:00

Pull tracing updates from Steven Rostedt:
"As the merge window is still open, and this code was not as complex as
I thought it might be. I'm pushing this in now.

This will allow Thomas to debug his irq work for 3.20.

This adds two new features:

1) Allow traceopoints to be enabled right after mm_init().

By passing in the trace_event= kernel command line parameter,
tracepoints can be enabled at boot up. For debugging things like
the initialization of interrupts, it is needed to have tracepoints
enabled very early. People have asked about this before and this
has been on my todo list. As it can be helpful for Thomas to debug
his upcoming 3.20 IRQ work, I'm pushing this now. This way he can
add tracepoints into the IRQ set up and have users enable them when
things go wrong.

2) Have the tracepoints printed via printk() (the console) when they
are triggered.

If the irq code locks up or reboots the box, having the tracepoint
output go into the kernel ring buffer is useless for debugging.
But being able to add the tp_printk kernel command line option
along with the trace_event= option will have these tracepoints
printed as they occur, and that can be really useful for debugging
early lock up or reboot problems.

This code is not that intrusive and it passed all my tests. Thomas
tried them out too and it works for his needs.

Link: http://lkml.kernel.org/r/20141214201609.126831471@goodmis.org"

* tag 'trace-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Add tp_printk cmdline to have tracepoints go to printk()
tracing: Move enabling tracepoints to just after rcu_init()

tracing: Add tp_printk cmdline to have tracepoints go to printk()

2014-12-15T15:17:38+00:00

Add the kernel command line tp_printk option that will have tracepoints
that are active sent to printk() as well as to the trace buffer.

Passing "tp_printk" will activate this. To turn it off, the sysctl
/proc/sys/kernel/tracepoint_printk can have '0' echoed into it. Note,
this only works if the cmdline option is used. Echoing 1 into the sysctl
file without the cmdline option will have no affect.

Note, this is a dangerous option. Having high frequency tracepoints send
their data to printk() can possibly cause a live lock. This is another
reason why this is only active if the command line option is used.

Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412121539300.16494@nanos

Suggested-by: Thomas Gleixner 
Tested-by: Thomas Gleixner 
Acked-by: Thomas Gleixner 
Signed-off-by: Steven Rostedt

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2014-12-15T04:36:37+00:00

Pull security layer updates from James Morris:
 "In terms of changes, there's general maintenance to the Smack,
  SELinux, and integrity code.

  The IMA code adds a new kconfig option, IMA_APPRAISE_SIGNED_INIT,
  which allows IMA appraisal to require signatures.  Support for reading
  keys from rootfs before init is call is also added"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (23 commits)
  selinux: Remove security_ops extern
  security: smack: fix out-of-bounds access in smk_parse_smack()
  VFS: refactor vfs_read()
  ima: require signature based appraisal
  integrity: provide a hook to load keys when rootfs is ready
  ima: load x509 certificate from the kernel
  integrity: provide a function to load x509 certificate from the kernel
  integrity: define a new function integrity_read_file()
  Security: smack: replace kzalloc with kmem_cache for inode_smack
  Smack: Lock mode for the floor and hat labels
  ima: added support for new kernel cmdline parameter ima_template_fmt
  ima: allocate field pointers array on demand in template_desc_init_fields()
  ima: don't allocate a copy of template_fmt in template_desc_init_fields()
  ima: display template format in meas. list if template name length is zero
  ima: added error messages to template-related functions
  ima: use atomic bit operations to protect policy update interface
  ima: ignore empty and with whitespaces policy lines
  ima: no need to allocate entry for comment
  ima: report policy load status
  ima: use path names cache
  ...

Merge branch 'akpm' (second patch-bomb from Andrew)

2014-12-13T21:00:36+00:00

Merge second patchbomb from Andrew Morton:
 - the rest of MM
 - misc fs fixes
 - add execveat() syscall
 - new ratelimit feature for fault-injection
 - decompressor updates
 - ipc/ updates
 - fallocate feature creep
 - fsnotify cleanups
 - a few other misc things

* emailed patches from Andrew Morton : (99 commits)
  cgroups: Documentation: fix trivial typos and wrong paragraph numberings
  parisc: percpu: update comments referring to __get_cpu_var
  percpu: update local_ops.txt to reflect this_cpu operations
  percpu: remove __get_cpu_var and __raw_get_cpu_var macros
  fsnotify: remove destroy_list from fsnotify_mark
  fsnotify: unify inode and mount marks handling
  fallocate: create FAN_MODIFY and IN_MODIFY events
  mm/cma: make kmemleak ignore CMA regions
  slub: fix cpuset check in get_any_partial
  slab: fix cpuset check in fallback_alloc
  shmdt: use i_size_read() instead of ->i_size
  ipc/shm.c: fix overly aggressive shmdt() when calls span multiple segments
  ipc/msg: increase MSGMNI, remove scaling
  ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM
  ipc/sem.c: change memory barrier in sem_lock() to smp_rmb()
  lib/decompress.c: consistency of compress formats for kernel image
  decompress_bunzip2: off by one in get_next_block()
  usr/Kconfig: make initrd compression algorithm selection not expert
  fault-inject: add ratelimit option
  ratelimit: add initialization macro
  ...

mm/page_owner: keep track of page owners

2014-12-13T20:42:48+00:00

This is the page owner tracking code which is introduced so far ago.  It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is.  Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.

This functionality help us to know who allocates the page.  When
allocating a page, we store some information about allocation in extra
memory.  Later, if we need to know status of all pages, we can get and
analyze it from this stored information.

In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page.  It enables us to turn on/off this feature at boottime
without considerable memory waste.

Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex.  We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.

Moreover, we can use page_owner feature further for various purposes.  For
example, we can use it for fragmentation statistics implemented in this
patch.  And, I also plan to implement some CMA failure debugging feature
using this interface.

I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history.  Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.

Contributor:
Alexander Nyberg 
Mel Gorman 
Dave Hansen 
Minchan Kim 
Michal Nazarewicz 
Andrew Morton 
Jungsoo Son 

Signed-off-by: Joonsoo Kim 
Cc: Mel Gorman 
Cc: Johannes Weiner 
Cc: Minchan Kim 
Cc: Dave Hansen 
Cc: Michal Nazarewicz 
Cc: Jungsoo Son 
Cc: Ingo Molnar 
Cc: Joonsoo Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/debug-pagealloc: make debug-pagealloc boottime configurable

2014-12-13T20:42:48+00:00

Now, we have prepared to avoid using debug-pagealloc in boottime.  So
introduce new kernel-parameter to disable debug-pagealloc in boottime, and
makes related functions to be disabled in this case.

Only non-intuitive part is change of guard page functions.  Because guard
page is effective only if debug-pagealloc is enabled, turning off
according to debug-pagealloc is reasonable thing to do.

Signed-off-by: Joonsoo Kim 
Cc: Mel Gorman 
Cc: Johannes Weiner 
Cc: Minchan Kim 
Cc: Dave Hansen 
Cc: Michal Nazarewicz 
Cc: Jungsoo Son 
Cc: Ingo Molnar 
Cc: Joonsoo Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlb: fix hugepages= entry in kernel-parameters.txt

2014-12-13T20:42:47+00:00

The hugepages= entry in kernel-parameters.txt states that 1GB pages can
only be allocated at boot time and not freed afterwards.  This is not
true since commit 944d9fec8d7a ("hugetlb: add support for gigantic page
allocation at runtime"), at least for x86_64.

Instead of adding arch-specifc observations to the hugepages= entry,
this commit just drops the out of date information.  Further information
about arch-specific support and available features can be obtained in
the hugetlb documentation.

Signed-off-by: Luiz Capitulino 
Cc: Andi Kleen 
Acked-by: David Rientjes 
Cc: Rik van Riel 
Cc: Yasuaki Ishimatsu 
Cc: Yinghai Lu 
Cc: Davidlohr Bueso 
Acked-by: Naoya Horiguchi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'docs-for-linus' of git://git.lwn.net/linux-2.6

2014-12-12T22:42:48+00:00

Pull documentation update from Jonathan Corbet:
 "Here's my set of accumulated documentation changes for 3.19.

  It includes a couple of additions to the coding style document, some
  fixes for minor build problems within the documentation tree, the
  relocation of the kselftest docs, and various tweaks and additions.

  A couple of changes reach outside of Documentation/; they only make
  trivial comment changes and I did my best to get the required acks.

  Complete with a shiny signed tag this time around"

* tag 'docs-for-linus' of git://git.lwn.net/linux-2.6:
  kobject: grammar fix
  Input: xpad - update docs to reflect current state
  Documentation: Build mic/mpssd only for x86_64
  cgroups: Documentation: fix wrong cgroupfs paths
  Documentation/email-clients.txt: add info about Claws Mail
  CodingStyle: add some more error handling guidelines
  kselftest: Move the docs to the Documentation dir
  Documentation: fix formatting to make 's' happy
  Documentation: power: Fix typo in Documentation/power
  Documentation: vm: Add 1GB large page support information
  ipv4: add kernel parameter tcpmhash_entries
  Documentation: Fix a typo in mailbox.txt
  treewide: Fix typo in Documentation/DocBook/device-drivers
  CodingStyle: Add a chapter on conditional compilation