<feed xmlns='http://www.w3.org/2005/Atom'>
<title>lwn.git/include/linux/sysctl.h, branch v2.6.19.2</title>
<subtitle>Linux kernel documentation tree maintained by Jonathan Corbet</subtitle>
<id>http://mirrors.hust.edu.cn/git/lwn.git/atom?h=v2.6.19.2</id>
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<updated>2006-11-06T09:46:23+00:00</updated>
<entry>
<title>[PATCH] sysctl: implement CTL_UNNUMBERED</title>
<updated>2006-11-06T09:46:23+00:00</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2006-11-06T07:52:13+00:00</published>
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<id>urn:sha1:7cc13edc139108bb527b692f0548dce6bc648572</id>
<content type='text'>
This patch takes the CTL_UNNUMBERD concept from NFS and makes it available to
all new sysctl users.

At the same time the sysctl binary interface maintenance documentation is
updated to mention and to describe what is needed to successfully maintain the
sysctl binary interface.

Signed-off-by: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Acked-by: Alan Cox &lt;alan@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
</entry>
<entry>
<title>[PATCH] sysctl: allow a zero ctl_name in the middle of a sysctl table</title>
<updated>2006-11-06T09:46:23+00:00</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2006-11-06T07:52:12+00:00</published>
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<id>urn:sha1:d99f160ac53e51090f015a8f0617cea25f81a191</id>
<content type='text'>
Since it is becoming clear that there are just enough users of the binary
sysctl interface that completely removing the binary interface from the kernel
will not be an option for foreseeable future, we need to find a way to address
the sysctl maintenance issues.

The basic problem is that sysctl requires one central authority to allocate
sysctl numbers, or else conflicts and ABI breakage occur.  The proc interface
to sysctl does not have that problem, as names are not densely allocated.

By not terminating a sysctl table until I have neither a ctl_name nor a
procname, it becomes simple to add sysctl entries that don't show up in the
binary sysctl interface.  Which allows people to avoid allocating a binary
sysctl value when not needed.

I have audited the kernel code and in my reading I have not found a single
sysctl table that wasn't terminated by a completely zero filled entry.  So
this change in behavior should not affect anything.

I think this mechanism eases the pain enough that combined with a little
disciple we can solve the reoccurring sysctl ABI breakage.

Signed-off-by: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Acked-by: Alan Cox &lt;alan@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
</entry>
<entry>
<title>Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6</title>
<updated>2006-09-26T20:07:55+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@g5.osdl.org</email>
</author>
<published>2006-09-26T20:07:55+00:00</published>
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<id>urn:sha1:b278240839e20fa9384ea430df463b367b90e04e</id>
<content type='text'>
* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6: (225 commits)
  [PATCH] Don't set calgary iommu as default y
  [PATCH] i386/x86-64: New Intel feature flags
  [PATCH] x86: Add a cumulative thermal throttle event counter.
  [PATCH] i386: Make the jiffies compares use the 64bit safe macros.
  [PATCH] x86: Refactor thermal throttle processing
  [PATCH] Add 64bit jiffies compares (for use with get_jiffies_64)
  [PATCH] Fix unwinder warning in traps.c
  [PATCH] x86: Allow disabling early pci scans with pci=noearly or disallowing conf1
  [PATCH] x86: Move direct PCI scanning functions out of line
  [PATCH] i386/x86-64: Make all early PCI scans dependent on CONFIG_PCI
  [PATCH] Don't leak NT bit into next task
  [PATCH] i386/x86-64: Work around gcc bug with noreturn functions in unwinder
  [PATCH] Fix some broken white space in ia32_signal.c
  [PATCH] Initialize argument registers for 32bit signal handlers.
  [PATCH] Remove all traces of signal number conversion
  [PATCH] Don't synchronize time reading on single core AMD systems
  [PATCH] Remove outdated comment in x86-64 mmconfig code
  [PATCH] Use string instructions for Core2 copy/clear
  [PATCH] x86: - restore i8259A eoi status on resume
  [PATCH] i386: Split multi-line printk in oops output.
  ...
</content>
</entry>
<entry>
<title>[PATCH] zone_reclaim: dynamic slab reclaim</title>
<updated>2006-09-26T15:48:51+00:00</updated>
<author>
<name>Christoph Lameter</name>
<email>clameter@sgi.com</email>
</author>
<published>2006-09-26T06:31:52+00:00</published>
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<id>urn:sha1:0ff38490c836dc379ff7ec45b10a15a662f4e5f6</id>
<content type='text'>
Currently one can enable slab reclaim by setting an explicit option in
/proc/sys/vm/zone_reclaim_mode.  Slab reclaim is then used as a final
option if the freeing of unmapped file backed pages is not enough to free
enough pages to allow a local allocation.

However, that means that the slab can grow excessively and that most memory
of a node may be used by slabs.  We have had a case where a machine with
46GB of memory was using 40-42GB for slab.  Zone reclaim was effective in
dealing with pagecache pages.  However, slab reclaim was only done during
global reclaim (which is a bit rare on NUMA systems).

This patch implements slab reclaim during zone reclaim.  Zone reclaim
occurs if there is a danger of an off node allocation.  At that point we

1. Shrink the per node page cache if the number of pagecache
   pages is more than min_unmapped_ratio percent of pages in a zone.

2. Shrink the slab cache if the number of the nodes reclaimable slab pages
   (patch depends on earlier one that implements that counter)
   are more than min_slab_ratio (a new /proc/sys/vm tunable).

The shrinking of the slab cache is a bit problematic since it is not node
specific.  So we simply calculate what point in the slab we want to reach
(current per node slab use minus the number of pages that neeed to be
allocated) and then repeately run the global reclaim until that is
unsuccessful or we have reached the limit.  I hope we will have zone based
slab reclaim at some point which will make that easier.

The default for the min_slab_ratio is 5%

Also remove the slab option from /proc/sys/vm/zone_reclaim_mode.

[akpm@osdl.org: cleanups]
Signed-off-by: Christoph Lameter &lt;clameter@sgi.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
</entry>
<entry>
<title>[PATCH] x86: Allow users to force a panic on NMI</title>
<updated>2006-09-26T08:52:27+00:00</updated>
<author>
<name>Don Zickus</name>
<email>dzickus@redhat.com</email>
</author>
<published>2006-09-26T08:52:27+00:00</published>
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<id>urn:sha1:8da5adda91df3d2fcc5300e68da491694c9af019</id>
<content type='text'>
To quote Alan Cox:

The default Linux behaviour on an NMI of either memory or unknown is to
continue operation. For many environments such as scientific computing
it is preferable that the box is taken out and the error dealt with than
an uncorrected parity/ECC error get propogated.

A small number of systems do generate NMI's for bizarre random reasons
such as power management so the default is unchanged. In other respects
the new proc/sys entry works like the existing panic controls already in
that directory.

This is separate to the edac support - EDAC allows supported chipsets to
handle ECC errors well, this change allows unsupported cases to at least
panic rather than cause problems further down the line.

Signed-off-by: Don Zickus &lt;dzickus@redhat.com&gt;
Signed-off-by: Andi Kleen &lt;ak@suse.de&gt;
</content>
</entry>
<entry>
<title>[PATCH] x86: Add abilty to enable/disable nmi watchdog with sysctl</title>
<updated>2006-09-26T08:52:27+00:00</updated>
<author>
<name>Don Zickus</name>
<email>dzickus@redhat.com</email>
</author>
<published>2006-09-26T08:52:27+00:00</published>
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<id>urn:sha1:407984f1af259b31957c7c05075a454a751bb801</id>
<content type='text'>
Adds a new /proc/sys/kernel/nmi call that will enable/disable the nmi
watchdog.

Signed-off-by:  Don Zickus &lt;dzickus@redhat.com&gt;
Signed-off-by: Andi Kleen &lt;ak@suse.de&gt;
</content>
</entry>
<entry>
<title>[IPV6] NDISC: Add proxy_ndp sysctl.</title>
<updated>2006-09-22T22:20:25+00:00</updated>
<author>
<name>YOSHIFUJI Hideaki</name>
<email>yoshfuji@linux-ipv6.org</email>
</author>
<published>2006-09-22T21:43:49+00:00</published>
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<id>urn:sha1:fbea49e1e2404baa2d88ab47e2db89e49551b53b</id>
<content type='text'>
We do not always need proxy NDP functionality even we
enable forwarding.

Signed-off-by: YOSHIFUJI Hideaki &lt;yoshfuji@linux-ipv6.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>[NetLabel]: CIPSOv4 engine</title>
<updated>2006-09-22T21:53:33+00:00</updated>
<author>
<name>Paul Moore</name>
<email>paul.moore@hp.com</email>
</author>
<published>2006-08-03T23:48:06+00:00</published>
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<id>urn:sha1:446fda4f26822b2d42ab3396aafcedf38a9ff2b6</id>
<content type='text'>
Add support for the Commercial IP Security Option (CIPSO) to the IPv4
network stack.  CIPSO has become a de-facto standard for
trusted/labeled networking amongst existing Trusted Operating Systems
such as Trusted Solaris, HP-UX CMW, etc.  This implementation is
designed to be used with the NetLabel subsystem to provide explicit
packet labeling to LSM developers.

The CIPSO/IPv4 packet labeling works by the LSM calling a NetLabel API
function which attaches a CIPSO label (IPv4 option) to a given socket;
this in turn attaches the CIPSO label to every packet leaving the
socket without any extra processing on the outbound side.  On the
inbound side the individual packet's sk_buff is examined through a
call to a NetLabel API function to determine if a CIPSO/IPv4 label is
present and if so the security attributes of the CIPSO label are
returned to the caller of the NetLabel API function.

Signed-off-by: Paul Moore &lt;paul.moore@hp.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>[PATCH] ZVC/zone_reclaim: Leave 1% of unmapped pagecache pages for file I/O</title>
<updated>2006-07-03T22:26:59+00:00</updated>
<author>
<name>Christoph Lameter</name>
<email>clameter@sgi.com</email>
</author>
<published>2006-07-03T07:24:13+00:00</published>
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<id>urn:sha1:9614634fe6a138fd8ae044950700d2af8d203f97</id>
<content type='text'>
It turns out that it is advantageous to leave a small portion of unmapped file
backed pages if all of a zone's pages (or almost all pages) are allocated and
so the page allocator has to go off-node.

This allows recently used file I/O buffers to stay on the node and
reduces the times that zone reclaim is invoked if file I/O occurs
when we run out of memory in a zone.

The problem is that zone reclaim runs too frequently when the page cache is
used for file I/O (read write and therefore unmapped pages!) alone and we have
almost all pages of the zone allocated.  Zone reclaim may remove 32 unmapped
pages.  File I/O will use these pages for the next read/write requests and the
unmapped pages increase.  After the zone has filled up again zone reclaim will
remove it again after only 32 pages.  This cycle is too inefficient and there
are potentially too many zone reclaim cycles.

With the 1% boundary we may still remove all unmapped pages for file I/O in
zone reclaim pass.  However.  it will take a large number of read and writes
to get back to 1% again where we trigger zone reclaim again.

The zone reclaim 2.6.16/17 does not show this behavior because we have a 30
second timeout.

[akpm@osdl.org: rename the /proc file and the variable]
Signed-off-by: Christoph Lameter &lt;clameter@sgi.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
</entry>
<entry>
<title>[PATCH] pi-futex: rt mutex core</title>
<updated>2006-06-28T00:32:47+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@elte.hu</email>
</author>
<published>2006-06-27T09:54:53+00:00</published>
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<id>urn:sha1:23f78d4a03c53cbd75d87a795378ea540aa08c86</id>
<content type='text'>
Core functions for the rt-mutex subsystem.

Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Arjan van de Ven &lt;arjan@linux.intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
</entry>
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