<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/Kconfig, branch v2.6.30</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>mutex: have non-spinning mutexes on s390 by default</title>
<updated>2009-04-09T17:28:24+00:00</updated>
<author>
<name>Heiko Carstens</name>
<email>heiko.carstens@de.ibm.com</email>
</author>
<published>2009-04-09T16:48:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=36cd3c9f925b9307236505ae7ad1ad7ac4d4357c'/>
<id>36cd3c9f925b9307236505ae7ad1ad7ac4d4357c</id>
<content type='text'>
Impact: performance regression fix for s390

The adaptive spinning mutexes will not always do what one would expect on
virtualized architectures like s390. Especially the cpu_relax() loop in
mutex_spin_on_owner might hurt if the mutex holding cpu has been scheduled
away by the hypervisor.

We would end up in a cpu_relax() loop when there is no chance that the
state of the mutex changes until the target cpu has been scheduled again by
the hypervisor.

For that reason we should change the default behaviour to no-spin on s390.

We do have an instruction which allows to yield the current cpu in favour of
a different target cpu. Also we have an instruction which allows us to figure
out if the target cpu is physically backed.

However we need to do some performance tests until we can come up with
a solution that will do the right thing on s390.

Signed-off-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Acked-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
LKML-Reference: &lt;20090409184834.7a0df7b2@osiris.boeblingen.de.ibm.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Impact: performance regression fix for s390

The adaptive spinning mutexes will not always do what one would expect on
virtualized architectures like s390. Especially the cpu_relax() loop in
mutex_spin_on_owner might hurt if the mutex holding cpu has been scheduled
away by the hypervisor.

We would end up in a cpu_relax() loop when there is no chance that the
state of the mutex changes until the target cpu has been scheduled again by
the hypervisor.

For that reason we should change the default behaviour to no-spin on s390.

We do have an instruction which allows to yield the current cpu in favour of
a different target cpu. Also we have an instruction which allows us to figure
out if the target cpu is physically backed.

However we need to do some performance tests until we can come up with
a solution that will do the right thing on s390.

Signed-off-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Acked-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
LKML-Reference: &lt;20090409184834.7a0df7b2@osiris.boeblingen.de.ibm.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'tracing/core-v2' into tracing-for-linus</title>
<updated>2009-04-01T22:49:02+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@elte.hu</email>
</author>
<published>2009-04-01T19:54:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8302294f43250dc337108c51882a6007f2b1e2e0'/>
<id>8302294f43250dc337108c51882a6007f2b1e2e0</id>
<content type='text'>
Conflicts:
	include/linux/slub_def.h
	lib/Kconfig.debug
	mm/slob.c
	mm/slub.c
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Conflicts:
	include/linux/slub_def.h
	lib/Kconfig.debug
	mm/slob.c
	mm/slub.c
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: clean up menu</title>
<updated>2009-03-05T20:53:25+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@elte.hu</email>
</author>
<published>2009-03-05T20:19:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=40ada30f9621fbd831ac2437b9a2a399aad34b00'/>
<id>40ada30f9621fbd831ac2437b9a2a399aad34b00</id>
<content type='text'>
Clean up menu structure, introduce TRACING_SUPPORT switch that signals
whether an architecture supports various instrumentation mechanisms.

Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Clean up menu structure, introduce TRACING_SUPPORT switch that signals
whether an architecture supports various instrumentation mechanisms.

Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dma-debug: add Kconfig entry</title>
<updated>2009-03-05T13:36:50+00:00</updated>
<author>
<name>Joerg Roedel</name>
<email>joerg.roedel@amd.com</email>
</author>
<published>2009-01-09T11:14:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5ee00bd4691e7364bb7b62e2068d473cd5cb9320'/>
<id>5ee00bd4691e7364bb7b62e2068d473cd5cb9320</id>
<content type='text'>
Impact: add a Kconfig entry for DMA-API debugging

Signed-off-by: Joerg Roedel &lt;joerg.roedel@amd.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Impact: add a Kconfig entry for DMA-API debugging

Signed-off-by: Joerg Roedel &lt;joerg.roedel@amd.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[CVE-2009-0029] System call wrapper infrastructure</title>
<updated>2009-01-14T13:15:16+00:00</updated>
<author>
<name>Heiko Carstens</name>
<email>heiko.carstens@de.ibm.com</email>
</author>
<published>2009-01-14T13:13:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1a94bc34768e463a93cb3751819709ab0ea80a01'/>
<id>1a94bc34768e463a93cb3751819709ab0ea80a01</id>
<content type='text'>
From: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;

By selecting HAVE_SYSCALL_WRAPPERS architectures can activate
system call wrappers in order to sign extend system call arguments.

All architectures where the ABI defines that the caller of a function
has to perform sign extension probably need this.

Reported-by: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Acked-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Signed-off-by: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Signed-off-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
From: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;

By selecting HAVE_SYSCALL_WRAPPERS architectures can activate
system call wrappers in order to sign extend system call arguments.

All architectures where the ABI defines that the caller of a function
has to perform sign extension probably need this.

Reported-by: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Acked-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Signed-off-by: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Signed-off-by: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>oprofile: select RING_BUFFER</title>
<updated>2008-12-12T08:46:31+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@elte.hu</email>
</author>
<published>2008-12-12T08:38:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d69d59f49763e6bd047c591c6c1f84c8e13da931'/>
<id>d69d59f49763e6bd047c591c6c1f84c8e13da931</id>
<content type='text'>
Impact: build fix

OProfile now depends on the ring buffer infrastructure:

 arch/x86/oprofile/built-in.o: In function `oprofile_add_ibs_sample':
 : undefined reference to `ring_buffer_unlock_commit'

Select TRACING and RING_BUFFER when oprofile is enabled.

Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Impact: build fix

OProfile now depends on the ring buffer infrastructure:

 arch/x86/oprofile/built-in.o: In function `oprofile_add_ibs_sample':
 : undefined reference to `ring_buffer_unlock_commit'

Select TRACING and RING_BUFFER when oprofile is enabled.

Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>remove __ARCH_WANT_COMPAT_SYS_PTRACE</title>
<updated>2008-11-30T19:00:15+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2008-11-25T07:10:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=96b8936a9ed08746e47081458a5eb9e43a751e24'/>
<id>96b8936a9ed08746e47081458a5eb9e43a751e24</id>
<content type='text'>
All architectures now use the generic compat_sys_ptrace, as should every
new architecture that needs 32bit compat (if we'll ever get another).

Remove the now superflous __ARCH_WANT_COMPAT_SYS_PTRACE define, and also
kill a comment about __ARCH_SYS_PTRACE that was added after
__ARCH_SYS_PTRACE was already gone.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
All architectures now use the generic compat_sys_ptrace, as should every
new architecture that needs 32bit compat (if we'll ever get another).

Remove the now superflous __ARCH_WANT_COMPAT_SYS_PTRACE define, and also
kill a comment about __ARCH_SYS_PTRACE that was added after
__ARCH_SYS_PTRACE was already gone.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Change UTF8 chars in Kconfig help text about Oprofile AMD barcelona</title>
<updated>2008-10-27T18:15:39+00:00</updated>
<author>
<name>Jesper Dangaard Brouer</name>
<email>jdb@comx.dk</email>
</author>
<published>2008-10-24T13:05:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ba8b453de08c18cbc2453bcabfd0936c1d6695cb'/>
<id>ba8b453de08c18cbc2453bcabfd0936c1d6695cb</id>
<content type='text'>
Fixes screwing up text output when doing a make oldconfig and viewing
help text of "OProfile AMD IBS support".  When the terminal is
not using an UTF8 locale / LANG.  "make config" breaks terminal output
and its not possible to continue.

(Change added by changeset 852402cc Tue Jul 22 21:09:06 2008)

Signed-off-by: Jesper Dangaard Brouer &lt;hawk@comx.dk&gt;
Signed-off-by: Robert Richter &lt;robert.richter@amd.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fixes screwing up text output when doing a make oldconfig and viewing
help text of "OProfile AMD IBS support".  When the terminal is
not using an UTF8 locale / LANG.  "make config" breaks terminal output
and its not possible to continue.

(Change added by changeset 852402cc Tue Jul 22 21:09:06 2008)

Signed-off-by: Jesper Dangaard Brouer &lt;hawk@comx.dk&gt;
Signed-off-by: Robert Richter &lt;robert.richter@amd.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Kconfig: eliminate "def_bool n" constructs</title>
<updated>2008-10-16T18:21:31+00:00</updated>
<author>
<name>Jan Beulich</name>
<email>jbeulich@novell.com</email>
</author>
<published>2008-10-16T05:01:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9ba16087d9f996a93ab6f4453a52a4b24bc1f25c'/>
<id>9ba16087d9f996a93ab6f4453a52a4b24bc1f25c</id>
<content type='text'>
Using "def_bool n" is pointless, simply using bool here appears more
appropriate.

Further, retaining such options that don't have a prompt and aren't
selected by anything seems also at least questionable.

Signed-off-by: Jan Beulich &lt;jbeulich@novell.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Bartlomiej Zolnierkiewicz &lt;bzolnier@gmail.com&gt;
Cc: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Using "def_bool n" is pointless, simply using bool here appears more
appropriate.

Further, retaining such options that don't have a prompt and aren't
selected by anything seems also at least questionable.

Signed-off-by: Jan Beulich &lt;jbeulich@novell.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Bartlomiej Zolnierkiewicz &lt;bzolnier@gmail.com&gt;
Cc: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'linus' into oprofile-v2</title>
<updated>2008-10-13T09:05:51+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@elte.hu</email>
</author>
<published>2008-10-13T09:05:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=accba5f3965d6a9d1bf7c1e1a7995d17e9d521b6'/>
<id>accba5f3965d6a9d1bf7c1e1a7995d17e9d521b6</id>
<content type='text'>
Conflicts:
	arch/x86/kernel/apic_32.c
	arch/x86/oprofile/nmi_int.c
	include/linux/pci_ids.h
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Conflicts:
	arch/x86/kernel/apic_32.c
	arch/x86/oprofile/nmi_int.c
	include/linux/pci_ids.h
</pre>
</div>
</content>
</entry>
</feed>
