<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/x86/kernel/alternative.c, branch linux-3.7.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2012-10-01T17:47:45+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2012-10-01T17:47:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=08815bc267291ea0a4f7f348290efc555444d7a8'/>
<id>08815bc267291ea0a4f7f348290efc555444d7a8</id>
<content type='text'>
Pull x86/cleanups from Ingo Molnar:
 "Smaller cleanups"

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arch/x86: Remove unecessary semicolons
  x86, boot: Remove obsolete and unused constant RAMDISK
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86/cleanups from Ingo Molnar:
 "Smaller cleanups"

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arch/x86: Remove unecessary semicolons
  x86, boot: Remove obsolete and unused constant RAMDISK
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2012-10-01T17:46:27+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2012-10-01T17:46:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=da8347969f324db5f572581397d9b3a8e108cda4'/>
<id>da8347969f324db5f572581397d9b3a8e108cda4</id>
<content type='text'>
Pull x86/asm changes from Ingo Molnar:
 "The one change that stands out is the alternatives patching change
  that prevents us from ever patching back instructions from SMP to UP:
  this simplifies things and speeds up CPU hotplug.

  Other than that it's smaller fixes, cleanups and improvements."

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Unspaghettize do_trap()
  x86_64: Work around old GAS bug
  x86: Use REP BSF unconditionally
  x86: Prefer TZCNT over BFS
  x86/64: Adjust types of temporaries used by ffs()/fls()/fls64()
  x86: Drop unnecessary kernel_eflags variable on 64-bit
  x86/smp: Don't ever patch back to UP if we unplug cpus
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86/asm changes from Ingo Molnar:
 "The one change that stands out is the alternatives patching change
  that prevents us from ever patching back instructions from SMP to UP:
  this simplifies things and speeds up CPU hotplug.

  Other than that it's smaller fixes, cleanups and improvements."

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Unspaghettize do_trap()
  x86_64: Work around old GAS bug
  x86: Use REP BSF unconditionally
  x86: Prefer TZCNT over BFS
  x86/64: Adjust types of temporaries used by ffs()/fls()/fls64()
  x86: Drop unnecessary kernel_eflags variable on 64-bit
  x86/smp: Don't ever patch back to UP if we unplug cpus
</pre>
</div>
</content>
</entry>
<entry>
<title>arch/x86: Remove unecessary semicolons</title>
<updated>2012-09-19T15:32:48+00:00</updated>
<author>
<name>Peter Senna Tschudin</name>
<email>peter.senna@gmail.com</email>
</author>
<published>2012-09-18T16:36:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4b8073e467e6a66b6a5a8e799d28bc3b243c0d78'/>
<id>4b8073e467e6a66b6a5a8e799d28bc3b243c0d78</id>
<content type='text'>
Found by http://coccinelle.lip6.fr/

Signed-off-by: Peter Senna Tschudin &lt;peter.senna@gmail.com&gt;
Cc: avi@redhat.com
Cc: mtosatti@redhat.com
Cc: a.p.zijlstra@chello.nl
Cc: rusty@rustcorp.com.au
Cc: masami.hiramatsu.pt@hitachi.com
Cc: suresh.b.siddha@intel.com
Cc: joerg.roedel@amd.com
Cc: agordeev@redhat.com
Cc: yinghai@kernel.org
Cc: bhelgaas@google.com
Cc: liuj97@gmail.com
Link: http://lkml.kernel.org/r/1347986174-30287-7-git-send-email-peter.senna@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Found by http://coccinelle.lip6.fr/

Signed-off-by: Peter Senna Tschudin &lt;peter.senna@gmail.com&gt;
Cc: avi@redhat.com
Cc: mtosatti@redhat.com
Cc: a.p.zijlstra@chello.nl
Cc: rusty@rustcorp.com.au
Cc: masami.hiramatsu.pt@hitachi.com
Cc: suresh.b.siddha@intel.com
Cc: joerg.roedel@amd.com
Cc: agordeev@redhat.com
Cc: yinghai@kernel.org
Cc: bhelgaas@google.com
Cc: liuj97@gmail.com
Link: http://lkml.kernel.org/r/1347986174-30287-7-git-send-email-peter.senna@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/smp: Don't ever patch back to UP if we unplug cpus</title>
<updated>2012-08-23T08:45:13+00:00</updated>
<author>
<name>Rusty Russell</name>
<email>rusty@rustcorp.com.au</email>
</author>
<published>2012-08-06T07:59:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=816afe4ff98ee10b1d30fd66361be132a0a5cee6'/>
<id>816afe4ff98ee10b1d30fd66361be132a0a5cee6</id>
<content type='text'>
We still patch SMP instructions to UP variants if we boot with a
single CPU, but not at any other time.  In particular, not if we
unplug CPUs to return to a single cpu.

Paul McKenney points out:

 mean offline overhead is 6251/48=130.2 milliseconds.

 If I remove the alternatives_smp_switch() from the offline
 path [...] the mean offline overhead is 550/42=13.1 milliseconds

Basically, we're never going to get those 120ms back, and the
code is pretty messy.

We get rid of:

 1) The "smp-alt-once" boot option. It's actually "smp-alt-boot", the
    documentation is wrong. It's now the default.

 2) The skip_smp_alternatives flag used by suspend.

 3) arch_disable_nonboot_cpus_begin() and arch_disable_nonboot_cpus_end()
    which were only used to set this one flag.

Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Cc: Paul McKenney &lt;paul.mckenney@us.ibm.com&gt;
Cc: Suresh Siddha &lt;suresh.b.siddha@intel.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/87vcgwwive.fsf@rustcorp.com.au
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We still patch SMP instructions to UP variants if we boot with a
single CPU, but not at any other time.  In particular, not if we
unplug CPUs to return to a single cpu.

Paul McKenney points out:

 mean offline overhead is 6251/48=130.2 milliseconds.

 If I remove the alternatives_smp_switch() from the offline
 path [...] the mean offline overhead is 550/42=13.1 milliseconds

Basically, we're never going to get those 120ms back, and the
code is pretty messy.

We get rid of:

 1) The "smp-alt-once" boot option. It's actually "smp-alt-boot", the
    documentation is wrong. It's now the default.

 2) The skip_smp_alternatives flag used by suspend.

 3) arch_disable_nonboot_cpus_begin() and arch_disable_nonboot_cpus_end()
    which were only used to set this one flag.

Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Cc: Paul McKenney &lt;paul.mckenney@us.ibm.com&gt;
Cc: Suresh Siddha &lt;suresh.b.siddha@intel.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/87vcgwwive.fsf@rustcorp.com.au
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/alternatives: Fix p6 nops on non-modular kernels</title>
<updated>2012-08-22T10:09:49+00:00</updated>
<author>
<name>Avi Kivity</name>
<email>avi@redhat.com</email>
</author>
<published>2012-08-22T10:03:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cb09cad44f07044d9810f18f6f9a6a6f3771f979'/>
<id>cb09cad44f07044d9810f18f6f9a6a6f3771f979</id>
<content type='text'>
Probably a leftover from the early days of self-patching, p6nops
are marked __initconst_or_module, which causes them to be
discarded in a non-modular kernel.  If something later triggers
patching, it will overwrite kernel code with garbage.

Reported-by: Tomas Racek &lt;tracek@redhat.com&gt;
Signed-off-by: Avi Kivity &lt;avi@redhat.com&gt;
Cc: Michael Tokarev &lt;mjt@tls.msk.ru&gt;
Cc: Borislav Petkov &lt;borislav.petkov@amd.com&gt;
Cc: Marcelo Tosatti &lt;mtosatti@redhat.com&gt;
Cc: qemu-devel@nongnu.org
Cc: Anthony Liguori &lt;anthony@codemonkey.ws&gt;
Cc: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
Cc: Alan Cox &lt;alan@lxorguk.ukuu.org.uk&gt;
Cc: Alan Cox &lt;alan@linux.intel.com&gt;
Link: http://lkml.kernel.org/r/5034AE84.90708@redhat.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Probably a leftover from the early days of self-patching, p6nops
are marked __initconst_or_module, which causes them to be
discarded in a non-modular kernel.  If something later triggers
patching, it will overwrite kernel code with garbage.

Reported-by: Tomas Racek &lt;tracek@redhat.com&gt;
Signed-off-by: Avi Kivity &lt;avi@redhat.com&gt;
Cc: Michael Tokarev &lt;mjt@tls.msk.ru&gt;
Cc: Borislav Petkov &lt;borislav.petkov@amd.com&gt;
Cc: Marcelo Tosatti &lt;mtosatti@redhat.com&gt;
Cc: qemu-devel@nongnu.org
Cc: Anthony Liguori &lt;anthony@codemonkey.ws&gt;
Cc: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
Cc: Alan Cox &lt;alan@lxorguk.ukuu.org.uk&gt;
Cc: Alan Cox &lt;alan@linux.intel.com&gt;
Link: http://lkml.kernel.org/r/5034AE84.90708@redhat.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'linus' into x86/urgent</title>
<updated>2012-07-25T19:40:40+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2012-07-25T19:40:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d431adfbc9b7de651f3164c6b7ffcad75805d7e4'/>
<id>d431adfbc9b7de651f3164c6b7ffcad75805d7e4</id>
<content type='text'>
Merge in Linus's tree to avoid a conflict.

Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge in Linus's tree to avoid a conflict.

Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86, nops: Missing break resulting in incorrect selection on Intel</title>
<updated>2012-07-25T15:35:38+00:00</updated>
<author>
<name>Alan Cox</name>
<email>alan@linux.intel.com</email>
</author>
<published>2012-07-25T15:28:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d6250a3f12edb3a86db9598ffeca3de8b4a219e9'/>
<id>d6250a3f12edb3a86db9598ffeca3de8b4a219e9</id>
<content type='text'>
The Intel case falls through into the generic case which then changes
the values.  For cases like the P6 it doesn't do the right thing so
this seems to be a screwup.

Signed-off-by: Alan Cox &lt;alan@linux.intel.com&gt;
Link: http://lkml.kernel.org/n/tip-lww2uirad4skzjlmrm0vru8o@git.kernel.org
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The Intel case falls through into the generic case which then changes
the values.  For cases like the P6 it doesn't do the right thing so
this seems to be a screwup.

Signed-off-by: Alan Cox &lt;alan@linux.intel.com&gt;
Link: http://lkml.kernel.org/n/tip-lww2uirad4skzjlmrm0vru8o@git.kernel.org
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2012-07-22T19:04:44+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2012-07-22T19:04:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3fad0953a12f92289f1e35f091c4fa09d8e1884e'/>
<id>3fad0953a12f92289f1e35f091c4fa09d8e1884e</id>
<content type='text'>
Pull debug-for-linus git tree from Ingo Molnar.

Fix up trivial conflict in arch/x86/kernel/cpu/perf_event_intel.c due to
a printk() having changed to a pr_info() differently in the two branches.

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Move call to print_modules() out of show_regs()
  x86/mm: Mark free_initrd_mem() as __init
  x86/microcode: Mark microcode_id[] as __initconst
  x86/nmi: Clean up register_nmi_handler() usage
  x86: Save cr2 in NMI in case NMIs take a page fault (for i386)
  x86: Remove cmpxchg from i386 NMI nesting code
  x86: Save cr2 in NMI in case NMIs take a page fault
  x86/debug: Add KERN_&lt;LEVEL&gt; to bare printks, convert printks to pr_&lt;level&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull debug-for-linus git tree from Ingo Molnar.

Fix up trivial conflict in arch/x86/kernel/cpu/perf_event_intel.c due to
a printk() having changed to a pr_info() differently in the two branches.

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Move call to print_modules() out of show_regs()
  x86/mm: Mark free_initrd_mem() as __init
  x86/microcode: Mark microcode_id[] as __initconst
  x86/nmi: Clean up register_nmi_handler() usage
  x86: Save cr2 in NMI in case NMIs take a page fault (for i386)
  x86: Remove cmpxchg from i386 NMI nesting code
  x86: Save cr2 in NMI in case NMIs take a page fault
  x86/debug: Add KERN_&lt;LEVEL&gt; to bare printks, convert printks to pr_&lt;level&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/alternatives: Use atomic_xchg() instead atomic_dec_and_test() for stop_machine_text_poke()</title>
<updated>2012-06-13T13:08:37+00:00</updated>
<author>
<name>OGAWA Hirofumi</name>
<email>hirofumi@mail.parknet.co.jp</email>
</author>
<published>2012-06-07T13:20:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2f74759056797054122cdc70844137f70bb3f626'/>
<id>2f74759056797054122cdc70844137f70bb3f626</id>
<content type='text'>
stop_machine_text_poke() uses atomic_dec_and_test() to select one of
the CPUs executing that function to actually modify the code.

Since the variable is initialized to 1, subsequent CPUs will make the
variable go negative. Since going negative is uncommon/unexpected in
typical dec_and_test usage change this user to atomic_xchg().

This was found using a patch that warns on dec_and_test going
negative.

Signed-off-by: OGAWA Hirofumi &lt;hirofumi@mail.parknet.co.jp&gt;
Acked-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
[ Rewrote changelog ]
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/87zk8fgsx9.fsf@devron.myhome.or.jp
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
stop_machine_text_poke() uses atomic_dec_and_test() to select one of
the CPUs executing that function to actually modify the code.

Since the variable is initialized to 1, subsequent CPUs will make the
variable go negative. Since going negative is uncommon/unexpected in
typical dec_and_test usage change this user to atomic_xchg().

This was found using a patch that warns on dec_and_test going
negative.

Signed-off-by: OGAWA Hirofumi &lt;hirofumi@mail.parknet.co.jp&gt;
Acked-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
[ Rewrote changelog ]
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/87zk8fgsx9.fsf@devron.myhome.or.jp
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/debug: Add KERN_&lt;LEVEL&gt; to bare printks, convert printks to pr_&lt;level&gt;</title>
<updated>2012-06-06T07:17:22+00:00</updated>
<author>
<name>Joe Perches</name>
<email>joe@perches.com</email>
</author>
<published>2012-05-22T02:50:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c767a54ba0657e52e6edaa97cbe0b0a8bf1c1655'/>
<id>c767a54ba0657e52e6edaa97cbe0b0a8bf1c1655</id>
<content type='text'>
Use a more current logging style:

 - Bare printks should have a KERN_&lt;LEVEL&gt; for consistency's sake
 - Add pr_fmt where appropriate
 - Neaten some macro definitions
 - Convert some Ok output to OK
 - Use "%s: ", __func__ in pr_fmt for summit
 - Convert some printks to pr_&lt;level&gt;

Message output is not identical in all cases.

Signed-off-by: Joe Perches &lt;joe@perches.com&gt;
Cc: levinsasha928@gmail.com
Link: http://lkml.kernel.org/r/1337655007.24226.10.camel@joe2Laptop
[ merged two similar patches, tidied up the changelog ]
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use a more current logging style:

 - Bare printks should have a KERN_&lt;LEVEL&gt; for consistency's sake
 - Add pr_fmt where appropriate
 - Neaten some macro definitions
 - Convert some Ok output to OK
 - Use "%s: ", __func__ in pr_fmt for summit
 - Convert some printks to pr_&lt;level&gt;

Message output is not identical in all cases.

Signed-off-by: Joe Perches &lt;joe@perches.com&gt;
Cc: levinsasha928@gmail.com
Link: http://lkml.kernel.org/r/1337655007.24226.10.camel@joe2Laptop
[ merged two similar patches, tidied up the changelog ]
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
