Skip to content

R
raspberrypi-kernel

openeuler / raspberrypi-kernel

通知 13
Star 1
Fork 0
R
raspberrypi-kernel
切换分支/标签
  1. 25 12月, 2008 1 次提交
    • I
      rcu: provide RCU options on non-preempt architectures too · 12d79baf
      由 Ingo Molnar 提交于 
      Impact: build fix

Some old architectures still do not use kernel/Kconfig.preempt, so the
moving of the RCU options there broke their build:

 In file included from /home/mingo/tip/include/linux/sem.h:81,
                 from /home/mingo/tip/include/linux/sched.h:69,
                 from /home/mingo/tip/arch/alpha/kernel/asm-offsets.c:9:
 /home/mingo/tip/include/linux/rcupdate.h:62:2: error: #error "Unknown RCU implementation specified to kernel configuration"

Move these options back to init/Kconfig, which every architecture
includes.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      12d79baf
  3. 20 12月, 2008 1 次提交
    • J
      allow stripping of generated symbols under CONFIG_KALLSYMS_ALL · 9bb48247
      由 Jan Beulich 提交于 
      Building upon parts of the module stripping patch, this patch
introduces similar stripping for vmlinux when CONFIG_KALLSYMS_ALL=y.
Using CONFIG_KALLSYMS_STRIP_GENERATED reduces the overhead of
CONFIG_KALLSYMS_ALL from 245k/310k to 65k/80k for the (i386/x86-64)
kernels I tested with.

The patch also does away with the need to special case the kallsyms-
internal symbols by making them available even in the first linking
stage.

While it is a generated file, the patch includes the changes to
scripts/genksyms/keywords.c_shipped, as I'm unsure what the procedure
here is.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
      9bb48247
  5. 19 12月, 2008 1 次提交
    • P
      "Tree RCU": scalable classic RCU implementation · 64db4cff
      由 Paul E. McKenney 提交于 
      This patch fixes a long-standing performance bug in classic RCU that
results in massive internal-to-RCU lock contention on systems with
more than a few hundred CPUs.  Although this patch creates a separate
flavor of RCU for ease of review and patch maintenance, it is intended
to replace classic RCU.

This patch still handles stress better than does mainline, so I am still
calling it ready for inclusion.  This patch is against the -tip tree.
Nevertheless, experience on an actual 1000+ CPU machine would still be
most welcome.

Most of the changes noted below were found while creating an rcutiny
(which should permit ejecting the current rcuclassic) and while doing
detailed line-by-line documentation.

Updates from v9 (http://lkml.org/lkml/2008/12/2/334):

o	Fixes from remainder of line-by-line code walkthrough,
	including comment spelling, initialization, undesirable
	narrowing due to type conversion, removing redundant memory
	barriers, removing redundant local-variable initialization,
	and removing redundant local variables.

	I do not believe that any of these fixes address the CPU-hotplug
	issues that Andi Kleen was seeing, but please do give it a whirl
	in case the machine is smarter than I am.

	A writeup from the walkthrough may be found at the following
	URL, in case you are suffering from terminal insomnia or
	masochism:

	http://www.kernel.org/pub/linux/kernel/people/paulmck/tmp/rcutree-walkthrough.2008.12.16a.pdf

o	Made rcutree tracing use seq_file, as suggested some time
	ago by Lai Jiangshan.

o	Added a .csv variant of the rcudata debugfs trace file, to allow
	people having thousands of CPUs to drop the data into
	a spreadsheet.	Tested with oocalc and gnumeric.  Updated
	documentation to suit.

Updates from v8 (http://lkml.org/lkml/2008/11/15/139):

o	Fix a theoretical race between grace-period initialization and
	force_quiescent_state() that could occur if more than three
	jiffies were required to carry out the grace-period
	initialization.  Which it might, if you had enough CPUs.

o	Apply Ingo's printk-standardization patch.

o	Substitute local variables for repeated accesses to global
	variables.

o	Fix comment misspellings and redundant (but harmless) increments
	of ->n_rcu_pending (this latter after having explicitly added it).

o	Apply checkpatch fixes.

Updates from v7 (http://lkml.org/lkml/2008/10/10/291):

o	Fixed a number of problems noted by Gautham Shenoy, including
	the cpu-stall-detection bug that he was having difficulty
	convincing me was real.  ;-)

o	Changed cpu-stall detection to wait for ten seconds rather than
	three in order to reduce false positive, as suggested by Ingo
	Molnar.

o	Produced a design document (http://lwn.net/Articles/305782/).
	The act of writing this document uncovered a number of both
	theoretical and "here and now" bugs as noted below.

o	Fix dynticks_nesting accounting confusion, simplify WARN_ON()
	condition, fix kerneldoc comments, and add memory barriers
	in dynticks interface functions.

o	Add more data to tracing.

o	Remove unused "rcu_barrier" field from rcu_data structure.

o	Count calls to rcu_pending() from scheduling-clock interrupt
	to use as a surrogate timebase should jiffies stop counting.

o	Fix a theoretical race between force_quiescent_state() and
	grace-period initialization.  Yes, initialization does have to
	go on for some jiffies for this race to occur, but given enough
	CPUs...

Updates from v6 (http://lkml.org/lkml/2008/9/23/448):

o	Fix a number of checkpatch.pl complaints.

o	Apply review comments from Ingo Molnar and Lai Jiangshan
	on the stall-detection code.

o	Fix several bugs in !CONFIG_SMP builds.

o	Fix a misspelled config-parameter name so that RCU now announces
	at boot time if stall detection is configured.

o	Run tests on numerous combinations of configurations parameters,
	which after the fixes above, now build and run correctly.

Updates from v5 (http://lkml.org/lkml/2008/9/15/92, bad subject line):

o	Fix a compiler error in the !CONFIG_FANOUT_EXACT case (blew a
	changeset some time ago, and finally got around to retesting
	this option).

o	Fix some tracing bugs in rcupreempt that caused incorrect
	totals to be printed.

o	I now test with a more brutal random-selection online/offline
	script (attached).  Probably more brutal than it needs to be
	on the people reading it as well, but so it goes.

o	A number of optimizations and usability improvements:

	o	Make rcu_pending() ignore the grace-period timeout when
		there is no grace period in progress.

	o	Make force_quiescent_state() avoid going for a global
		lock in the case where there is no grace period in
		progress.

	o	Rearrange struct fields to improve struct layout.

	o	Make call_rcu() initiate a grace period if RCU was
		idle, rather than waiting for the next scheduling
		clock interrupt.

	o	Invoke rcu_irq_enter() and rcu_irq_exit() only when
		idle, as suggested by Andi Kleen.  I still don't
		completely trust this change, and might back it out.

	o	Make CONFIG_RCU_TRACE be the single config variable
		manipulated for all forms of RCU, instead of the prior
		confusion.

	o	Document tracing files and formats for both rcupreempt
		and rcutree.

Updates from v4 for those missing v5 given its bad subject line:

o	Separated dynticks interface so that NMIs and irqs call separate
	functions, greatly simplifying it.  In particular, this code
	no longer requires a proof of correctness.  ;-)

o	Separated dynticks state out into its own per-CPU structure,
	avoiding the duplicated accounting.

o	The case where a dynticks-idle CPU runs an irq handler that
	invokes call_rcu() is now correctly handled, forcing that CPU
	out of dynticks-idle mode.

o	Review comments have been applied (thank you all!!!).
	For but one example, fixed the dynticks-ordering issue that
	Manfred pointed out, saving me much debugging.  ;-)

o	Adjusted rcuclassic and rcupreempt to handle dynticks changes.

Attached is an updated patch to Classic RCU that applies a hierarchy,
greatly reducing the contention on the top-level lock for large machines.
This passes 10-hour concurrent rcutorture and online-offline testing on
128-CPU ppc64 without dynticks enabled, and exposes some timekeeping
bugs in presence of dynticks (exciting working on a system where
"sleep 1" hangs until interrupted...), which were fixed in the
2.6.27 kernel.  It is getting more reliable than mainline by some
measures, so the next version will be against -tip for inclusion.
See also Manfred Spraul's recent patches (or his earlier work from
2004 at http://marc.info/?l=linux-kernel&m=108546384711797&w=2).
We will converge onto a common patch in the fullness of time, but are
currently exploring different regions of the design space.  That said,
I have already gratefully stolen quite a few of Manfred's ideas.

This patch provides CONFIG_RCU_FANOUT, which controls the bushiness
of the RCU hierarchy.  Defaults to 32 on 32-bit machines and 64 on
64-bit machines.  If CONFIG_NR_CPUS is less than CONFIG_RCU_FANOUT,
there is no hierarchy.  By default, the RCU initialization code will
adjust CONFIG_RCU_FANOUT to balance the hierarchy, so strongly NUMA
architectures may choose to set CONFIG_RCU_FANOUT_EXACT to disable
this balancing, allowing the hierarchy to be exactly aligned to the
underlying hardware.  Up to two levels of hierarchy are permitted
(in addition to the root node), allowing up to 16,384 CPUs on 32-bit
systems and up to 262,144 CPUs on 64-bit systems.  I just know that I
am going to regret saying this, but this seems more than sufficient
for the foreseeable future.  (Some architectures might wish to set
CONFIG_RCU_FANOUT=4, which would limit such architectures to 64 CPUs.
If this becomes a real problem, additional levels can be added, but I
doubt that it will make a significant difference on real hardware.)

In the common case, a given CPU will manipulate its private rcu_data
structure and the rcu_node structure that it shares with its immediate
neighbors.  This can reduce both lock and memory contention by multiple
orders of magnitude, which should eliminate the need for the strange
manipulations that are reported to be required when running Linux on
very large systems.

Some shortcomings:

o	More bugs will probably surface as a result of an ongoing
	line-by-line code inspection.

	Patches will be provided as required.

o	There are probably hangs, rcutorture failures, &c.  Seems
	quite stable on a 128-CPU machine, but that is kind of small
	compared to 4096 CPUs.  However, seems to do better than
	mainline.

	Patches will be provided as required.

o	The memory footprint of this version is several KB larger
	than rcuclassic.

	A separate UP-only rcutiny patch will be provided, which will
	reduce the memory footprint significantly, even compared
	to the old rcuclassic.  One such patch passes light testing,
	and has a memory footprint smaller even than rcuclassic.
	Initial reaction from various embedded guys was "it is not
	worth it", so am putting it aside.

Credits:

o	Manfred Spraul for ideas, review comments, and bugs spotted,
	as well as some good friendly competition.  ;-)

o	Josh Triplett, Ingo Molnar, Peter Zijlstra, Mathieu Desnoyers,
	Lai Jiangshan, Andi Kleen, Andy Whitcroft, and Andrew Morton
	for reviews and comments.

o	Thomas Gleixner for much-needed help with some timer issues
	(see patches below).

o	Jon M. Tollefson, Tim Pepper, Andrew Theurer, Jose R. Santos,
	Andy Whitcroft, Darrick Wong, Nishanth Aravamudan, Anton
	Blanchard, Dave Kleikamp, and Nathan Lynch for keeping machines
	alive despite my heavy abuse^Wtesting.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      64db4cff
  7. 16 11月, 2008 1 次提交
  9. 14 11月, 2008 1 次提交
  11. 13 11月, 2008 1 次提交
  13. 31 10月, 2008 1 次提交
  15. 23 10月, 2008 1 次提交
  17. 21 10月, 2008 1 次提交
    • T
      PCI: allow quirks to be compiled out · 3d137310
      由 Thomas Petazzoni 提交于 
      This patch adds the CONFIG_PCI_QUIRKS option which allows to remove all
the PCI quirks, which are not necessarily used on embedded systems when
PCI is working properly. As this is a size-reduction option, it depends
on CONFIG_EMBEDDED. It allows to save almost 12 kilobytes of kernel
code:

   text	   data	    bss	    dec	    hex	filename
1287806	 123596	 212992	1624394	 18c94a	vmlinux.old
1275854	 123596	 212992	1612442	 189a9a	vmlinux
 -11952       0       0  -11952   -2EB0 +/-

This patch has originally been written by Zwane Mwaikambo
<zwane@arm.linux.org.uk> and is part of the Linux Tiny project.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
      3d137310
  19. 20 10月, 2008 1 次提交
    • M
      container freezer: implement freezer cgroup subsystem · dc52ddc0
      由 Matt Helsley 提交于 
      This patch implements a new freezer subsystem in the control groups
framework.  It provides a way to stop and resume execution of all tasks in
a cgroup by writing in the cgroup filesystem.

The freezer subsystem in the container filesystem defines a file named
freezer.state.  Writing "FROZEN" to the state file will freeze all tasks
in the cgroup.  Subsequently writing "RUNNING" will unfreeze the tasks in
the cgroup.  Reading will return the current state.

* Examples of usage :

   # mkdir /containers/freezer
   # mount -t cgroup -ofreezer freezer  /containers
   # mkdir /containers/0
   # echo $some_pid > /containers/0/tasks

to get status of the freezer subsystem :

   # cat /containers/0/freezer.state
   RUNNING

to freeze all tasks in the container :

   # echo FROZEN > /containers/0/freezer.state
   # cat /containers/0/freezer.state
   FREEZING
   # cat /containers/0/freezer.state
   FROZEN

to unfreeze all tasks in the container :

   # echo RUNNING > /containers/0/freezer.state
   # cat /containers/0/freezer.state
   RUNNING

This is the basic mechanism which should do the right thing for user space
task in a simple scenario.

It's important to note that freezing can be incomplete.  In that case we
return EBUSY.  This means that some tasks in the cgroup are busy doing
something that prevents us from completely freezing the cgroup at this
time.  After EBUSY, the cgroup will remain partially frozen -- reflected
by freezer.state reporting "FREEZING" when read.  The state will remain
"FREEZING" until one of these things happens:

	1) Userspace cancels the freezing operation by writing "RUNNING" to
		the freezer.state file
	2) Userspace retries the freezing operation by writing "FROZEN" to
		the freezer.state file (writing "FREEZING" is not legal
		and returns EIO)
	3) The tasks that blocked the cgroup from entering the "FROZEN"
		state disappear from the cgroup's set of tasks.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: export thaw_process]
Signed-off-by: NCedric Le Goater <clg@fr.ibm.com>
Signed-off-by: NMatt Helsley <matthltc@us.ibm.com>
Acked-by: NSerge E. Hallyn <serue@us.ibm.com>
Tested-by: NMatt Helsley <matthltc@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      dc52ddc0
  21. 17 10月, 2008 1 次提交
  23. 14 10月, 2008 3 次提交
    • I
      tracing: clean up tracepoints kconfig structure · 5f87f112
      由 Ingo Molnar 提交于 
      do not expose users to CONFIG_TRACEPOINTS - tracers can select it
just fine.

update ftrace to select CONFIG_TRACEPOINTS.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      5f87f112
    • I
      tracing: disable tracepoints by default · fa340d9c
      由 Ingo Molnar 提交于 
      while it's arguably low overhead, we dont enable new features by default.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      fa340d9c
    • M
      tracing: Kernel Tracepoints · 97e1c18e
      由 Mathieu Desnoyers 提交于 
      Implementation of kernel tracepoints. Inspired from the Linux Kernel
Markers. Allows complete typing verification by declaring both tracing
statement inline functions and probe registration/unregistration static
inline functions within the same macro "DEFINE_TRACE". No format string
is required. See the tracepoint Documentation and Samples patches for
usage examples.

Taken from the documentation patch :

"A tracepoint placed in code provides a hook to call a function (probe)
that you can provide at runtime. A tracepoint can be "on" (a probe is
connected to it) or "off" (no probe is attached). When a tracepoint is
"off" it has no effect, except for adding a tiny time penalty (checking
a condition for a branch) and space penalty (adding a few bytes for the
function call at the end of the instrumented function and adds a data
structure in a separate section).  When a tracepoint is "on", the
function you provide is called each time the tracepoint is executed, in
the execution context of the caller. When the function provided ends its
execution, it returns to the caller (continuing from the tracepoint
site).

You can put tracepoints at important locations in the code. They are
lightweight hooks that can pass an arbitrary number of parameters, which
prototypes are described in a tracepoint declaration placed in a header
file."

Addition and removal of tracepoints is synchronized by RCU using the
scheduler (and preempt_disable) as guarantees to find a quiescent state
(this is really RCU "classic"). The update side uses rcu_barrier_sched()
with call_rcu_sched() and the read/execute side uses
"preempt_disable()/preempt_enable()".

We make sure the previous array containing probes, which has been
scheduled for deletion by the rcu callback, is indeed freed before we
proceed to the next update. It therefore limits the rate of modification
of a single tracepoint to one update per RCU period. The objective here
is to permit fast batch add/removal of probes on _different_
tracepoints.

Changelog :
- Use #name ":" #proto as string to identify the tracepoint in the
  tracepoint table. This will make sure not type mismatch happens due to
  connexion of a probe with the wrong type to a tracepoint declared with
  the same name in a different header.
- Add tracepoint_entry_free_old.
- Change __TO_TRACE to get rid of the 'i' iterator.

Masami Hiramatsu <mhiramat@redhat.com> :
Tested on x86-64.

Performance impact of a tracepoint : same as markers, except that it
adds about 70 bytes of instructions in an unlikely branch of each
instrumented function (the for loop, the stack setup and the function
call). It currently adds a memory read, a test and a conditional branch
at the instrumentation site (in the hot path). Immediate values will
eventually change this into a load immediate, test and branch, which
removes the memory read which will make the i-cache impact smaller
(changing the memory read for a load immediate removes 3-4 bytes per
site on x86_32 (depending on mov prefixes), or 7-8 bytes on x86_64, it
also saves the d-cache hit).

About the performance impact of tracepoints (which is comparable to
markers), even without immediate values optimizations, tests done by
Hideo Aoki on ia64 show no regression. His test case was using hackbench
on a kernel where scheduler instrumentation (about 5 events in code
scheduler code) was added.

Quoting Hideo Aoki about Markers :

I evaluated overhead of kernel marker using linux-2.6-sched-fixes git
tree, which includes several markers for LTTng, using an ia64 server.

While the immediate trace mark feature isn't implemented on ia64, there
is no major performance regression. So, I think that we don't have any
issues to propose merging marker point patches into Linus's tree from
the viewpoint of performance impact.

I prepared two kernels to evaluate. The first one was compiled without
CONFIG_MARKERS. The second one was enabled CONFIG_MARKERS.

I downloaded the original hackbench from the following URL:
http://devresources.linux-foundation.org/craiger/hackbench/src/hackbench.c

I ran hackbench 5 times in each condition and calculated the average and
difference between the kernels.

    The parameter of hackbench: every 50 from 50 to 800
    The number of CPUs of the server: 2, 4, and 8

Below is the results. As you can see, major performance regression
wasn't found in any case. Even if number of processes increases,
differences between marker-enabled kernel and marker- disabled kernel
doesn't increase. Moreover, if number of CPUs increases, the differences
doesn't increase either.

Curiously, marker-enabled kernel is better than marker-disabled kernel
in more than half cases, although I guess it comes from the difference
of memory access pattern.

* 2 CPUs

Number of | without      | with         | diff     | diff    |
processes | Marker [Sec] | Marker [Sec] |   [Sec]  |   [%]   |
--------------------------------------------------------------
       50 |      4.811   |       4.872  |  +0.061  |  +1.27  |
      100 |      9.854   |      10.309  |  +0.454  |  +4.61  |
      150 |     15.602   |      15.040  |  -0.562  |  -3.6   |
      200 |     20.489   |      20.380  |  -0.109  |  -0.53  |
      250 |     25.798   |      25.652  |  -0.146  |  -0.56  |
      300 |     31.260   |      30.797  |  -0.463  |  -1.48  |
      350 |     36.121   |      35.770  |  -0.351  |  -0.97  |
      400 |     42.288   |      42.102  |  -0.186  |  -0.44  |
      450 |     47.778   |      47.253  |  -0.526  |  -1.1   |
      500 |     51.953   |      52.278  |  +0.325  |  +0.63  |
      550 |     58.401   |      57.700  |  -0.701  |  -1.2   |
      600 |     63.334   |      63.222  |  -0.112  |  -0.18  |
      650 |     68.816   |      68.511  |  -0.306  |  -0.44  |
      700 |     74.667   |      74.088  |  -0.579  |  -0.78  |
      750 |     78.612   |      79.582  |  +0.970  |  +1.23  |
      800 |     85.431   |      85.263  |  -0.168  |  -0.2   |
--------------------------------------------------------------

* 4 CPUs

Number of | without      | with         | diff     | diff    |
processes | Marker [Sec] | Marker [Sec] |   [Sec]  |   [%]   |
--------------------------------------------------------------
       50 |      2.586   |       2.584  |  -0.003  |  -0.1   |
      100 |      5.254   |       5.283  |  +0.030  |  +0.56  |
      150 |      8.012   |       8.074  |  +0.061  |  +0.76  |
      200 |     11.172   |      11.000  |  -0.172  |  -1.54  |
      250 |     13.917   |      14.036  |  +0.119  |  +0.86  |
      300 |     16.905   |      16.543  |  -0.362  |  -2.14  |
      350 |     19.901   |      20.036  |  +0.135  |  +0.68  |
      400 |     22.908   |      23.094  |  +0.186  |  +0.81  |
      450 |     26.273   |      26.101  |  -0.172  |  -0.66  |
      500 |     29.554   |      29.092  |  -0.461  |  -1.56  |
      550 |     32.377   |      32.274  |  -0.103  |  -0.32  |
      600 |     35.855   |      35.322  |  -0.533  |  -1.49  |
      650 |     39.192   |      38.388  |  -0.804  |  -2.05  |
      700 |     41.744   |      41.719  |  -0.025  |  -0.06  |
      750 |     45.016   |      44.496  |  -0.520  |  -1.16  |
      800 |     48.212   |      47.603  |  -0.609  |  -1.26  |
--------------------------------------------------------------

* 8 CPUs

Number of | without      | with         | diff     | diff    |
processes | Marker [Sec] | Marker [Sec] |   [Sec]  |   [%]   |
--------------------------------------------------------------
       50 |      2.094   |       2.072  |  -0.022  |  -1.07  |
      100 |      4.162   |       4.273  |  +0.111  |  +2.66  |
      150 |      6.485   |       6.540  |  +0.055  |  +0.84  |
      200 |      8.556   |       8.478  |  -0.078  |  -0.91  |
      250 |     10.458   |      10.258  |  -0.200  |  -1.91  |
      300 |     12.425   |      12.750  |  +0.325  |  +2.62  |
      350 |     14.807   |      14.839  |  +0.032  |  +0.22  |
      400 |     16.801   |      16.959  |  +0.158  |  +0.94  |
      450 |     19.478   |      19.009  |  -0.470  |  -2.41  |
      500 |     21.296   |      21.504  |  +0.208  |  +0.98  |
      550 |     23.842   |      23.979  |  +0.137  |  +0.57  |
      600 |     26.309   |      26.111  |  -0.198  |  -0.75  |
      650 |     28.705   |      28.446  |  -0.259  |  -0.9   |
      700 |     31.233   |      31.394  |  +0.161  |  +0.52  |
      750 |     34.064   |      33.720  |  -0.344  |  -1.01  |
      800 |     36.320   |      36.114  |  -0.206  |  -0.57  |
--------------------------------------------------------------
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: NMasami Hiramatsu <mhiramat@redhat.com>
Acked-by: N'Peter Zijlstra' <peterz@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      97e1c18e
  25. 10 10月, 2008 1 次提交
  27. 17 8月, 2008 1 次提交
  29. 07 8月, 2008 1 次提交
  31. 01 8月, 2008 1 次提交
  33. 26 7月, 2008 2 次提交
  35. 22 7月, 2008 2 次提交
  37. 30 6月, 2008 1 次提交
  39. 26 5月, 2008 1 次提交
    • S
      Kconfig: introduce ARCH_DEFCONFIG to DEFCONFIG_LIST · 73531905
      由 Sam Ravnborg 提交于 
      init/Kconfig contains a list of configs that are searched
for if 'make *config' are used with no .config present.
Extend this list to look at the config identified by
ARCH_DEFCONFIG.

With this change we now try the defconfig targets last.

This fixes a regression reported
by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
      73531905
  41. 09 5月, 2008 1 次提交
  43. 07 5月, 2008 1 次提交
  45. 06 5月, 2008 2 次提交
  47. 05 5月, 2008 1 次提交
    • L
      Make forced module loading optional · 826e4506
      由 Linus Torvalds 提交于 
      The kernel module loader used to be much too happy to allow loading of
modules for the wrong kernel version by default.  For example, if you
had MODVERSIONS enabled, but tried to load a module with no version
info, it would happily load it and taint the kernel - whether it was
likely to actually work or not!

Generally, such forced module loading should be considered a really
really bad idea, so make it conditional on a new config option
(MODULE_FORCE_LOAD), and make it default to off.

If somebody really wants to force module loads, that's their problem,
but we should not encourage it.  Especially as it happened to me by
mistake (ie regular unversioned Fedora modules getting loaded) causing
lots of strange behavior.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      826e4506
  49. 02 5月, 2008 1 次提交
  51. 29 4月, 2008 6 次提交
    • H
      sysctl: allow embedded targets to disable sysctl_check.c · 88f458e4
      由 Holger Schurig 提交于 
      Disable sysctl_check.c for embedded targets. This saves about about 11 kB
in .text and another 11 kB in .data on a PXA255 embedded platform.
Signed-off-by: NHolger Schurig <hs4233@mail.mn-solutions.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      88f458e4
    • B
      cgroups: add an owner to the mm_struct · cf475ad2
      由 Balbir Singh 提交于 
      Remove the mem_cgroup member from mm_struct and instead adds an owner.

This approach was suggested by Paul Menage.  The advantage of this approach
is that, once the mm->owner is known, using the subsystem id, the cgroup
can be determined.  It also allows several control groups that are
virtually grouped by mm_struct, to exist independent of the memory
controller i.e., without adding mem_cgroup's for each controller, to
mm_struct.

A new config option CONFIG_MM_OWNER is added and the memory resource
controller selects this config option.

This patch also adds cgroup callbacks to notify subsystems when mm->owner
changes.  The mm_cgroup_changed callback is called with the task_lock() of
the new task held and is called just prior to changing the mm->owner.

I am indebted to Paul Menage for the several reviews of this patchset and
helping me make it lighter and simpler.

This patch was tested on a powerpc box, it was compiled with both the
MM_OWNER config turned on and off.

After the thread group leader exits, it's moved to init_css_state by
cgroup_exit(), thus all future charges from runnings threads would be
redirected to the init_css_set's subsystem.
Signed-off-by: NBalbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: David Rientjes <rientjes@google.com>,
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: NPaul Menage <menage@google.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      cf475ad2
    • S
      cgroups: implement device whitelist · 08ce5f16
      由 Serge E. Hallyn 提交于 
      Implement a cgroup to track and enforce open and mknod restrictions on device
files.  A device cgroup associates a device access whitelist with each cgroup.
 A whitelist entry has 4 fields.  'type' is a (all), c (char), or b (block).
'all' means it applies to all types and all major and minor numbers.  Major
and minor are either an integer or * for all.  Access is a composition of r
(read), w (write), and m (mknod).

The root device cgroup starts with rwm to 'all'.  A child devcg gets a copy of
the parent.  Admins can then remove devices from the whitelist or add new
entries.  A child cgroup can never receive a device access which is denied its
parent.  However when a device access is removed from a parent it will not
also be removed from the child(ren).

An entry is added using devices.allow, and removed using
devices.deny.  For instance

	echo 'c 1:3 mr' > /cgroups/1/devices.allow

allows cgroup 1 to read and mknod the device usually known as
/dev/null.  Doing

	echo a > /cgroups/1/devices.deny

will remove the default 'a *:* mrw' entry.

CAP_SYS_ADMIN is needed to change permissions or move another task to a new
cgroup.  A cgroup may not be granted more permissions than the cgroup's parent
has.  Any task can move itself between cgroups.  This won't be sufficient, but
we can decide the best way to adequately restrict movement later.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix may-be-used-uninitialized warning]
Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com>
Acked-by: NJames Morris <jmorris@namei.org>
Looks-good-to: Pavel Emelyanov <xemul@openvz.org>
Cc: Daniel Hokka Zakrisson <daniel@hozac.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      08ce5f16
    • P
      CGroup API files: make CGROUP_DEBUG default to off · 418d7d87
      由 Paul Menage 提交于 
      The cgroup debug subsystem isn't generally useful for users.  It should
default to "n".
Signed-off-by: NPaul Menage <menage@google.com>
Cc: "Li Zefan" <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      418d7d87
    • A
      let LOG_BUF_SHIFT default to 17 · f17a32e9
      由 Adrian Bunk 提交于 
      16 kB is often no longer enough for a normal boot of an UP system.

And even less when people e.g. use suspend.

17 seems to be a more reasonable default for current kernels on current
hardware (it's just the default, anyone who is memory limited can still lower
it).
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f17a32e9
    • I
      make CC_OPTIMIZE_FOR_SIZE non-experimental · 96fffeb4
      由 Ingo Molnar 提交于 
      this option has been the default on a wide range of distributions
for a long time - time to make it non-experimental.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      96fffeb4
  53. 27 4月, 2008 1 次提交
  55. 20 4月, 2008 1 次提交
  57. 14 4月, 2008 1 次提交
    • C
      slub: No need for per node slab counters if !SLUB_DEBUG · 0f389ec6
      由 Christoph Lameter 提交于 
      The per node counters are used mainly for showing data through the sysfs API.
If that API is not compiled in then there is no point in keeping track of this
data. Disable counters for the number of slabs and the number of total slabs
if !SLUB_DEBUG. Incrementing the per node counters is also accessing a
potentially contended cacheline so this could actually be a performance
benefit to embedded systems.

SLABINFO support is also affected. It now must depends on SLUB_DEBUG (which
is on by default).

Patch also avoids a check for a NULL kmem_cache_node pointer in new_slab()
if the system is not compiled with NUMA support.

[penberg@cs.helsinki.fi: fix oops and move ->nr_slabs into CONFIG_SLUB_DEBUG]
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
      0f389ec6
  59. 11 3月, 2008 1 次提交
    • P
      rcu: move PREEMPT_RCU config option back under PREEMPT · 21bbb39c
      由 Paul E. McKenney 提交于 
      The original preemptible-RCU patch put the choice between classic and
preemptible RCU into kernel/Kconfig.preempt, which resulted in build failures
on machines not supporting CONFIG_PREEMPT.  This choice was therefore moved to
init/Kconfig, which worked, but placed the choice between classic and
preemptible RCU at the top level, a very obtuse choice indeed.

This patch changes from the Kconfig "choice" mechanism to a pair of booleans,
only one of which (CONFIG_PREEMPT_RCU) is user-visible, and is located in
kernel/Kconfig.preempt, where one would expect it to be.  The other
(CONFIG_CLASSIC_RCU) is in init/Kconfig so that it is available to all
architectures, hopefully avoiding build breakage.  Thanks to Roman Zippel for
suggesting this approach.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Josh Triplett <josh@freedesktop.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      21bbb39c