<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/mm/nobootmem.c, branch v4.10</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping</title>
<updated>2016-10-11T22:06:33+00:00</updated>
<author>
<name>Catalin Marinas</name>
<email>catalin.marinas@arm.com</email>
</author>
<published>2016-10-11T20:55:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9099daed9c6991a512c1f74b92ec49daf9408cda'/>
<id>9099daed9c6991a512c1f74b92ec49daf9408cda</id>
<content type='text'>
Some of the kmemleak_*() callbacks in memblock, bootmem, CMA convert a
physical address to a virtual one using __va().  However, such physical
addresses may sometimes be located in highmem and using __va() is
incorrect, leading to inconsistent object tracking in kmemleak.

The following functions have been added to the kmemleak API and they take
a physical address as the object pointer.  They only perform the
corresponding action if the address has a lowmem mapping:

kmemleak_alloc_phys
kmemleak_free_part_phys
kmemleak_not_leak_phys
kmemleak_ignore_phys

The affected calling places have been updated to use the new kmemleak
API.

Link: http://lkml.kernel.org/r/1471531432-16503-1-git-send-email-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Reported-by: Vignesh R &lt;vigneshr@ti.com&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>
Some of the kmemleak_*() callbacks in memblock, bootmem, CMA convert a
physical address to a virtual one using __va().  However, such physical
addresses may sometimes be located in highmem and using __va() is
incorrect, leading to inconsistent object tracking in kmemleak.

The following functions have been added to the kmemleak API and they take
a physical address as the object pointer.  They only perform the
corresponding action if the address has a lowmem mapping:

kmemleak_alloc_phys
kmemleak_free_part_phys
kmemleak_not_leak_phys
kmemleak_ignore_phys

The affected calling places have been updated to use the new kmemleak
API.

Link: http://lkml.kernel.org/r/1471531432-16503-1-git-send-email-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Reported-by: Vignesh R &lt;vigneshr@ti.com&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>mm: nobootmem: move the comment of free_all_bootmem</title>
<updated>2016-10-08T01:46:29+00:00</updated>
<author>
<name>Wanlong Gao</name>
<email>wanlong.gao@gmail.com</email>
</author>
<published>2016-10-08T00:01:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=914a051654c5401cb216a939e214e17ec018b6a9'/>
<id>914a051654c5401cb216a939e214e17ec018b6a9</id>
<content type='text'>
Commit b4def3509d18 ("mm, nobootmem: clean-up of free_low_memory_core_early()")
removed the unnecessary nodeid argument, after that, this comment
becomes more confused.  We should move it to the right place.

Fixes: b4def3509d18c1db9 ("mm, nobootmem: clean-up of free_low_memory_core_early()")
Link: http://lkml.kernel.org/r/1473996082-14603-1-git-send-email-wanlong.gao@gmail.com
Signed-off-by: Wanlong Gao &lt;wanlong.gao@gmail.com&gt;
Cc: Joonsoo Kim &lt;iamjoonsoo.kim@lge.com&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>
Commit b4def3509d18 ("mm, nobootmem: clean-up of free_low_memory_core_early()")
removed the unnecessary nodeid argument, after that, this comment
becomes more confused.  We should move it to the right place.

Fixes: b4def3509d18c1db9 ("mm, nobootmem: clean-up of free_low_memory_core_early()")
Link: http://lkml.kernel.org/r/1473996082-14603-1-git-send-email-wanlong.gao@gmail.com
Signed-off-by: Wanlong Gao &lt;wanlong.gao@gmail.com&gt;
Cc: Joonsoo Kim &lt;iamjoonsoo.kim@lge.com&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>mm/nobootmem.c: remove duplicate macro ARCH_LOW_ADDRESS_LIMIT statements</title>
<updated>2016-10-08T01:46:28+00:00</updated>
<author>
<name>zijun_hu</name>
<email>zijun_hu@htc.com</email>
</author>
<published>2016-10-07T23:59:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2382705f22c1436a153800cf6051b08f0ea14838'/>
<id>2382705f22c1436a153800cf6051b08f0ea14838</id>
<content type='text'>
Fix the following bugs:

 - the same ARCH_LOW_ADDRESS_LIMIT statements are duplicated between
   header and relevant source

 - don't ensure ARCH_LOW_ADDRESS_LIMIT perhaps defined by ARCH in
   asm/processor.h is preferred over default in linux/bootmem.h
   completely since the former header isn't included by the latter

Link: http://lkml.kernel.org/r/e046aeaa-e160-6d9e-dc1b-e084c2fd999f@zoho.com
Signed-off-by: zijun_hu &lt;zijun_hu@htc.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&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>
Fix the following bugs:

 - the same ARCH_LOW_ADDRESS_LIMIT statements are duplicated between
   header and relevant source

 - don't ensure ARCH_LOW_ADDRESS_LIMIT perhaps defined by ARCH in
   asm/processor.h is preferred over default in linux/bootmem.h
   completely since the former header isn't included by the latter

Link: http://lkml.kernel.org/r/e046aeaa-e160-6d9e-dc1b-e084c2fd999f@zoho.com
Signed-off-by: zijun_hu &lt;zijun_hu@htc.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&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>mm: convert printk(KERN_&lt;LEVEL&gt; to pr_&lt;level&gt;</title>
<updated>2016-03-17T22:09:34+00:00</updated>
<author>
<name>Joe Perches</name>
<email>joe@perches.com</email>
</author>
<published>2016-03-17T21:19:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1170532bb49f9468aedabdc1d5a560e2521a2bcc'/>
<id>1170532bb49f9468aedabdc1d5a560e2521a2bcc</id>
<content type='text'>
Most of the mm subsystem uses pr_&lt;level&gt; so make it consistent.

Miscellanea:

 - Realign arguments
 - Add missing newline to format
 - kmemleak-test.c has a "kmemleak: " prefix added to the
   "Kmemleak testing" logging message via pr_fmt

Signed-off-by: Joe Perches &lt;joe@perches.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;	[percpu]
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>
Most of the mm subsystem uses pr_&lt;level&gt; so make it consistent.

Miscellanea:

 - Realign arguments
 - Add missing newline to format
 - kmemleak-test.c has a "kmemleak: " prefix added to the
   "Kmemleak testing" logging message via pr_fmt

Signed-off-by: Joe Perches &lt;joe@perches.com&gt;
Acked-by: Tejun Heo &lt;tj@kernel.org&gt;	[percpu]
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>x86/mm: Introduce max_possible_pfn</title>
<updated>2015-12-06T11:46:31+00:00</updated>
<author>
<name>Igor Mammedov</name>
<email>imammedo@redhat.com</email>
</author>
<published>2015-12-04T13:07:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8dd3303001976aa8583bf20f6b93590c74114308'/>
<id>8dd3303001976aa8583bf20f6b93590c74114308</id>
<content type='text'>
max_possible_pfn will be used for tracking max possible
PFN for memory that isn't present in E820 table and
could be hotplugged later.

By default max_possible_pfn is initialized with max_pfn,
but later it could be updated with highest PFN of
hotpluggable memory ranges declared in ACPI SRAT table
if any present.

Signed-off-by: Igor Mammedov &lt;imammedo@redhat.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: akataria@vmware.com
Cc: fujita.tomonori@lab.ntt.co.jp
Cc: konrad.wilk@oracle.com
Cc: pbonzini@redhat.com
Cc: revers@redhat.com
Cc: riel@redhat.com
Link: http://lkml.kernel.org/r/1449234426-273049-2-git-send-email-imammedo@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>
max_possible_pfn will be used for tracking max possible
PFN for memory that isn't present in E820 table and
could be hotplugged later.

By default max_possible_pfn is initialized with max_pfn,
but later it could be updated with highest PFN of
hotpluggable memory ranges declared in ACPI SRAT table
if any present.

Signed-off-by: Igor Mammedov &lt;imammedo@redhat.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: akataria@vmware.com
Cc: fujita.tomonori@lab.ntt.co.jp
Cc: konrad.wilk@oracle.com
Cc: pbonzini@redhat.com
Cc: revers@redhat.com
Cc: riel@redhat.com
Link: http://lkml.kernel.org/r/1449234426-273049-2-git-send-email-imammedo@redhat.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: page_alloc: pass PFN to __free_pages_bootmem</title>
<updated>2015-07-01T02:44:55+00:00</updated>
<author>
<name>Mel Gorman</name>
<email>mgorman@suse.de</email>
</author>
<published>2015-06-30T21:56:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d70ddd7a5d9aa335f9b4b0c3d879e1e70ee1e4e3'/>
<id>d70ddd7a5d9aa335f9b4b0c3d879e1e70ee1e4e3</id>
<content type='text'>
__free_pages_bootmem prepares a page for release to the buddy allocator
and assumes that the struct page is initialised.  Parallel initialisation
of struct pages defers initialisation and __free_pages_bootmem can be
called for struct pages that cannot yet map struct page to PFN.  This
patch passes PFN to __free_pages_bootmem with no other functional change.

Signed-off-by: Mel Gorman &lt;mgorman@suse.de&gt;
Tested-by: Nate Zimmer &lt;nzimmer@sgi.com&gt;
Tested-by: Waiman Long &lt;waiman.long@hp.com&gt;
Tested-by: Daniel J Blueman &lt;daniel@numascale.com&gt;
Acked-by: Pekka Enberg &lt;penberg@kernel.org&gt;
Cc: Robin Holt &lt;robinmholt@gmail.com&gt;
Cc: Nate Zimmer &lt;nzimmer@sgi.com&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Waiman Long &lt;waiman.long@hp.com&gt;
Cc: Scott Norton &lt;scott.norton@hp.com&gt;
Cc: "Luck, Tony" &lt;tony.luck@intel.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&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>
__free_pages_bootmem prepares a page for release to the buddy allocator
and assumes that the struct page is initialised.  Parallel initialisation
of struct pages defers initialisation and __free_pages_bootmem can be
called for struct pages that cannot yet map struct page to PFN.  This
patch passes PFN to __free_pages_bootmem with no other functional change.

Signed-off-by: Mel Gorman &lt;mgorman@suse.de&gt;
Tested-by: Nate Zimmer &lt;nzimmer@sgi.com&gt;
Tested-by: Waiman Long &lt;waiman.long@hp.com&gt;
Tested-by: Daniel J Blueman &lt;daniel@numascale.com&gt;
Acked-by: Pekka Enberg &lt;penberg@kernel.org&gt;
Cc: Robin Holt &lt;robinmholt@gmail.com&gt;
Cc: Nate Zimmer &lt;nzimmer@sgi.com&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Waiman Long &lt;waiman.long@hp.com&gt;
Cc: Scott Norton &lt;scott.norton@hp.com&gt;
Cc: "Luck, Tony" &lt;tony.luck@intel.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&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>mm: meminit: only set page reserved in the memblock region</title>
<updated>2015-07-01T02:44:55+00:00</updated>
<author>
<name>Nathan Zimmer</name>
<email>nzimmer@sgi.com</email>
</author>
<published>2015-06-30T21:56:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=92923ca3aacef63c92dc297a75ad0c6dfe4eab37'/>
<id>92923ca3aacef63c92dc297a75ad0c6dfe4eab37</id>
<content type='text'>
Currently each page struct is set as reserved upon initialization.  This
patch leaves the reserved bit clear and only sets the reserved bit when it
is known the memory was allocated by the bootmem allocator.  This makes it
easier to distinguish between uninitialised struct pages and reserved
struct pages in later patches.

Signed-off-by: Robin Holt &lt;holt@sgi.com&gt;
Signed-off-by: Nathan Zimmer &lt;nzimmer@sgi.com&gt;
Signed-off-by: Mel Gorman &lt;mgorman@suse.de&gt;
Tested-by: Nate Zimmer &lt;nzimmer@sgi.com&gt;
Tested-by: Waiman Long &lt;waiman.long@hp.com&gt;
Tested-by: Daniel J Blueman &lt;daniel@numascale.com&gt;
Acked-by: Pekka Enberg &lt;penberg@kernel.org&gt;
Cc: Robin Holt &lt;robinmholt@gmail.com&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Waiman Long &lt;waiman.long@hp.com&gt;
Cc: Scott Norton &lt;scott.norton@hp.com&gt;
Cc: "Luck, Tony" &lt;tony.luck@intel.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&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>
Currently each page struct is set as reserved upon initialization.  This
patch leaves the reserved bit clear and only sets the reserved bit when it
is known the memory was allocated by the bootmem allocator.  This makes it
easier to distinguish between uninitialised struct pages and reserved
struct pages in later patches.

Signed-off-by: Robin Holt &lt;holt@sgi.com&gt;
Signed-off-by: Nathan Zimmer &lt;nzimmer@sgi.com&gt;
Signed-off-by: Mel Gorman &lt;mgorman@suse.de&gt;
Tested-by: Nate Zimmer &lt;nzimmer@sgi.com&gt;
Tested-by: Waiman Long &lt;waiman.long@hp.com&gt;
Tested-by: Daniel J Blueman &lt;daniel@numascale.com&gt;
Acked-by: Pekka Enberg &lt;penberg@kernel.org&gt;
Cc: Robin Holt &lt;robinmholt@gmail.com&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Waiman Long &lt;waiman.long@hp.com&gt;
Cc: Scott Norton &lt;scott.norton@hp.com&gt;
Cc: "Luck, Tony" &lt;tony.luck@intel.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&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>mm/memblock: allocate boot time data structures from mirrored memory</title>
<updated>2015-06-25T00:49:45+00:00</updated>
<author>
<name>Tony Luck</name>
<email>tony.luck@intel.com</email>
</author>
<published>2015-06-24T23:58:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a3f5bafcc04aaf62990e0cf3ced1cc6d8dc6fe95'/>
<id>a3f5bafcc04aaf62990e0cf3ced1cc6d8dc6fe95</id>
<content type='text'>
Try to allocate all boot time kernel data structures from mirrored
memory.

If we run out of mirrored memory print warnings, but fall back to using
non-mirrored memory to make sure that we still boot.

By number of bytes, most of what we allocate at boot time is the page
structures.  64 bytes per 4K page on x86_64 ...  or about 1.5% of total
system memory.  For workloads where the bulk of memory is allocated to
applications this may represent a useful improvement to system
availability since 1.5% of total memory might be a third of the memory
allocated to the kernel.

Signed-off-by: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Xishi Qiu &lt;qiuxishi@huawei.com&gt;
Cc: Hanjun Guo &lt;guohanjun@huawei.com&gt;
Cc: Xiexiuqi &lt;xiexiuqi@huawei.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Yinghai Lu &lt;yinghai@kernel.org&gt;
Cc: Naoya Horiguchi &lt;nao.horiguchi@gmail.com&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>
Try to allocate all boot time kernel data structures from mirrored
memory.

If we run out of mirrored memory print warnings, but fall back to using
non-mirrored memory to make sure that we still boot.

By number of bytes, most of what we allocate at boot time is the page
structures.  64 bytes per 4K page on x86_64 ...  or about 1.5% of total
system memory.  For workloads where the bulk of memory is allocated to
applications this may represent a useful improvement to system
availability since 1.5% of total memory might be a third of the memory
allocated to the kernel.

Signed-off-by: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Xishi Qiu &lt;qiuxishi@huawei.com&gt;
Cc: Hanjun Guo &lt;guohanjun@huawei.com&gt;
Cc: Xiexiuqi &lt;xiexiuqi@huawei.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Yinghai Lu &lt;yinghai@kernel.org&gt;
Cc: Naoya Horiguchi &lt;nao.horiguchi@gmail.com&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>mm/memblock: add extra "flags" to memblock to allow selection of memory based on attribute</title>
<updated>2015-06-25T00:49:44+00:00</updated>
<author>
<name>Tony Luck</name>
<email>tony.luck@intel.com</email>
</author>
<published>2015-06-24T23:58:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fc6daaf93151877748f8096af6b3fddb147f22d6'/>
<id>fc6daaf93151877748f8096af6b3fddb147f22d6</id>
<content type='text'>
Some high end Intel Xeon systems report uncorrectable memory errors as a
recoverable machine check.  Linux has included code for some time to
process these and just signal the affected processes (or even recover
completely if the error was in a read only page that can be replaced by
reading from disk).

But we have no recovery path for errors encountered during kernel code
execution.  Except for some very specific cases were are unlikely to ever
be able to recover.

Enter memory mirroring. Actually 3rd generation of memory mirroing.

Gen1: All memory is mirrored
	Pro: No s/w enabling - h/w just gets good data from other side of the
	     mirror
	Con: Halves effective memory capacity available to OS/applications

Gen2: Partial memory mirror - just mirror memory begind some memory controllers
	Pro: Keep more of the capacity
	Con: Nightmare to enable. Have to choose between allocating from
	     mirrored memory for safety vs. NUMA local memory for performance

Gen3: Address range partial memory mirror - some mirror on each memory
      controller
	Pro: Can tune the amount of mirror and keep NUMA performance
	Con: I have to write memory management code to implement

The current plan is just to use mirrored memory for kernel allocations.
This has been broken into two phases:

1) This patch series - find the mirrored memory, use it for boot time
   allocations

2) Wade into mm/page_alloc.c and define a ZONE_MIRROR to pick up the
   unused mirrored memory from mm/memblock.c and only give it out to
   select kernel allocations (this is still being scoped because
   page_alloc.c is scary).

This patch (of 3):

Add extra "flags" to memblock to allow selection of memory based on
attribute.  No functional changes

Signed-off-by: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Xishi Qiu &lt;qiuxishi@huawei.com&gt;
Cc: Hanjun Guo &lt;guohanjun@huawei.com&gt;
Cc: Xiexiuqi &lt;xiexiuqi@huawei.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Yinghai Lu &lt;yinghai@kernel.org&gt;
Cc: Naoya Horiguchi &lt;nao.horiguchi@gmail.com&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>
Some high end Intel Xeon systems report uncorrectable memory errors as a
recoverable machine check.  Linux has included code for some time to
process these and just signal the affected processes (or even recover
completely if the error was in a read only page that can be replaced by
reading from disk).

But we have no recovery path for errors encountered during kernel code
execution.  Except for some very specific cases were are unlikely to ever
be able to recover.

Enter memory mirroring. Actually 3rd generation of memory mirroing.

Gen1: All memory is mirrored
	Pro: No s/w enabling - h/w just gets good data from other side of the
	     mirror
	Con: Halves effective memory capacity available to OS/applications

Gen2: Partial memory mirror - just mirror memory begind some memory controllers
	Pro: Keep more of the capacity
	Con: Nightmare to enable. Have to choose between allocating from
	     mirrored memory for safety vs. NUMA local memory for performance

Gen3: Address range partial memory mirror - some mirror on each memory
      controller
	Pro: Can tune the amount of mirror and keep NUMA performance
	Con: I have to write memory management code to implement

The current plan is just to use mirrored memory for kernel allocations.
This has been broken into two phases:

1) This patch series - find the mirrored memory, use it for boot time
   allocations

2) Wade into mm/page_alloc.c and define a ZONE_MIRROR to pick up the
   unused mirrored memory from mm/memblock.c and only give it out to
   select kernel allocations (this is still being scoped because
   page_alloc.c is scary).

This patch (of 3):

Add extra "flags" to memblock to allow selection of memory based on
attribute.  No functional changes

Signed-off-by: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Xishi Qiu &lt;qiuxishi@huawei.com&gt;
Cc: Hanjun Guo &lt;guohanjun@huawei.com&gt;
Cc: Xiexiuqi &lt;xiexiuqi@huawei.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Yinghai Lu &lt;yinghai@kernel.org&gt;
Cc: Naoya Horiguchi &lt;nao.horiguchi@gmail.com&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>mem-hotplug: reset node managed pages when hot-adding a new pgdat</title>
<updated>2014-11-14T00:17:06+00:00</updated>
<author>
<name>Tang Chen</name>
<email>tangchen@cn.fujitsu.com</email>
</author>
<published>2014-11-13T23:19:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f784a3f19613901ca4539a5b0eed3bdc700e6ee7'/>
<id>f784a3f19613901ca4539a5b0eed3bdc700e6ee7</id>
<content type='text'>
In free_area_init_core(), zone-&gt;managed_pages is set to an approximate
value for lowmem, and will be adjusted when the bootmem allocator frees
pages into the buddy system.

But free_area_init_core() is also called by hotadd_new_pgdat() when
hot-adding memory.  As a result, zone-&gt;managed_pages of the newly added
node's pgdat is set to an approximate value in the very beginning.

Even if the memory on that node has node been onlined,
/sys/device/system/node/nodeXXX/meminfo has wrong value:

  hot-add node2 (memory not onlined)
  cat /sys/device/system/node/node2/meminfo
  Node 2 MemTotal:       33554432 kB
  Node 2 MemFree:               0 kB
  Node 2 MemUsed:        33554432 kB
  Node 2 Active:                0 kB

This patch fixes this problem by reset node managed pages to 0 after
hot-adding a new node.

1. Move reset_managed_pages_done from reset_node_managed_pages() to
   reset_all_zones_managed_pages()
2. Make reset_node_managed_pages() non-static
3. Call reset_node_managed_pages() in hotadd_new_pgdat() after pgdat
   is initialized

Signed-off-by: Tang Chen &lt;tangchen@cn.fujitsu.com&gt;
Signed-off-by: Yasuaki Ishimatsu &lt;isimatu.yasuaki@jp.fujitsu.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;	[3.16+]
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>
In free_area_init_core(), zone-&gt;managed_pages is set to an approximate
value for lowmem, and will be adjusted when the bootmem allocator frees
pages into the buddy system.

But free_area_init_core() is also called by hotadd_new_pgdat() when
hot-adding memory.  As a result, zone-&gt;managed_pages of the newly added
node's pgdat is set to an approximate value in the very beginning.

Even if the memory on that node has node been onlined,
/sys/device/system/node/nodeXXX/meminfo has wrong value:

  hot-add node2 (memory not onlined)
  cat /sys/device/system/node/node2/meminfo
  Node 2 MemTotal:       33554432 kB
  Node 2 MemFree:               0 kB
  Node 2 MemUsed:        33554432 kB
  Node 2 Active:                0 kB

This patch fixes this problem by reset node managed pages to 0 after
hot-adding a new node.

1. Move reset_managed_pages_done from reset_node_managed_pages() to
   reset_all_zones_managed_pages()
2. Make reset_node_managed_pages() non-static
3. Call reset_node_managed_pages() in hotadd_new_pgdat() after pgdat
   is initialized

Signed-off-by: Tang Chen &lt;tangchen@cn.fujitsu.com&gt;
Signed-off-by: Yasuaki Ishimatsu &lt;isimatu.yasuaki@jp.fujitsu.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;	[3.16+]
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>
</feed>
