<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/arc/kernel/setup.c, branch v5.0-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge branch 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs</title>
<updated>2019-01-05T21:25:58+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-01-05T21:25:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=505b050fdf42097883b2d37b8e796e1f11dbef50'/>
<id>505b050fdf42097883b2d37b8e796e1f11dbef50</id>
<content type='text'>
Pull vfs mount API prep from Al Viro:
 "Mount API prereqs.

  Mostly that's LSM mount options cleanups. There are several minor
  fixes in there, but nothing earth-shattering (leaks on failure exits,
  mostly)"

* 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (27 commits)
  mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNT
  smack: rewrite smack_sb_eat_lsm_opts()
  smack: get rid of match_token()
  smack: take the guts of smack_parse_opts_str() into a new helper
  LSM: new method: -&gt;sb_add_mnt_opt()
  selinux: rewrite selinux_sb_eat_lsm_opts()
  selinux: regularize Opt_... names a bit
  selinux: switch away from match_token()
  selinux: new helper - selinux_add_opt()
  LSM: bury struct security_mnt_opts
  smack: switch to private smack_mnt_opts
  selinux: switch to private struct selinux_mnt_opts
  LSM: hide struct security_mnt_opts from any generic code
  selinux: kill selinux_sb_get_mnt_opts()
  LSM: turn sb_eat_lsm_opts() into a method
  nfs_remount(): don't leak, don't ignore LSM options quietly
  btrfs: sanitize security_mnt_opts use
  selinux; don't open-code a loop in sb_finish_set_opts()
  LSM: split -&gt;sb_set_mnt_opts() out of -&gt;sb_kern_mount()
  new helper: security_sb_eat_lsm_opts()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull vfs mount API prep from Al Viro:
 "Mount API prereqs.

  Mostly that's LSM mount options cleanups. There are several minor
  fixes in there, but nothing earth-shattering (leaks on failure exits,
  mostly)"

* 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (27 commits)
  mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNT
  smack: rewrite smack_sb_eat_lsm_opts()
  smack: get rid of match_token()
  smack: take the guts of smack_parse_opts_str() into a new helper
  LSM: new method: -&gt;sb_add_mnt_opt()
  selinux: rewrite selinux_sb_eat_lsm_opts()
  selinux: regularize Opt_... names a bit
  selinux: switch away from match_token()
  selinux: new helper - selinux_add_opt()
  LSM: bury struct security_mnt_opts
  smack: switch to private smack_mnt_opts
  selinux: switch to private struct selinux_mnt_opts
  LSM: hide struct security_mnt_opts from any generic code
  selinux: kill selinux_sb_get_mnt_opts()
  LSM: turn sb_eat_lsm_opts() into a method
  nfs_remount(): don't leak, don't ignore LSM options quietly
  btrfs: sanitize security_mnt_opts use
  selinux; don't open-code a loop in sb_finish_set_opts()
  LSM: split -&gt;sb_set_mnt_opts() out of -&gt;sb_kern_mount()
  new helper: security_sb_eat_lsm_opts()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>vfs: Suppress MS_* flag defs within the kernel unless explicitly enabled</title>
<updated>2018-12-20T16:32:56+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2018-11-01T23:07:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e262e32d6bde0f77fb0c95d977482fc872c51996'/>
<id>e262e32d6bde0f77fb0c95d977482fc872c51996</id>
<content type='text'>
Only the mount namespace code that implements mount(2) should be using the
MS_* flags.  Suppress them inside the kernel unless uapi/linux/mount.h is
included.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Reviewed-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Only the mount namespace code that implements mount(2) should be using the
MS_* flags.  Suppress them inside the kernel unless uapi/linux/mount.h is
included.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Reviewed-by: David Howells &lt;dhowells@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARCv2: boot log unaligned access in use</title>
<updated>2018-11-12T18:38:27+00:00</updated>
<author>
<name>Vineet Gupta</name>
<email>vgupta@synopsys.com</email>
</author>
<published>2018-10-29T16:44:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=afba5d157fe1f2e64bc3df46fe83841657ec8fdd'/>
<id>afba5d157fe1f2e64bc3df46fe83841657ec8fdd</id>
<content type='text'>
ARC gcc 8.x generates unaligned accesses by default, so call that out

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
ARC gcc 8.x generates unaligned accesses by default, so call that out

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARCv2: boot log: fix HS48 release number</title>
<updated>2018-02-28T18:45:30+00:00</updated>
<author>
<name>Vineet Gupta</name>
<email>vgupta@synopsys.com</email>
</author>
<published>2018-02-21T23:10:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=701eda01cbd212bae2f7d29cf14322bd49b94657'/>
<id>701eda01cbd212bae2f7d29cf14322bd49b94657</id>
<content type='text'>
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARC: boot log: Fix trailing semicolon</title>
<updated>2018-01-23T19:12:28+00:00</updated>
<author>
<name>Luis de Bethencourt</name>
<email>luisbg@kernel.org</email>
</author>
<published>2018-01-23T15:16:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a46f24acf8bce70b5fdd6774793d121e54b99e97'/>
<id>a46f24acf8bce70b5fdd6774793d121e54b99e97</id>
<content type='text'>
The trailing semicolon is an empty statement that does no operation.
Removing it since it doesn't do anything.

Signed-off-by: Luis de Bethencourt &lt;luisbg@kernel.org&gt;
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The trailing semicolon is an empty statement that does no operation.
Removing it since it doesn't do anything.

Signed-off-by: Luis de Bethencourt &lt;luisbg@kernel.org&gt;
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARC: Fix detection of dual-issue enabled</title>
<updated>2017-11-29T02:12:07+00:00</updated>
<author>
<name>Alexey Brodkin</name>
<email>Alexey.Brodkin@synopsys.com</email>
</author>
<published>2017-11-23T10:21:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=329b4130bc5eb2a1b123a652b985dbdb08d6b9a8'/>
<id>329b4130bc5eb2a1b123a652b985dbdb08d6b9a8</id>
<content type='text'>
As per PRM bit #0 ("D") in EXEC_CTRL enables dual-issue if set to 0,
otherwise if set to 1 all instructions are executed one at a time,
i.e. dual-issue is disabled.

Signed-off-by: Alexey Brodkin &lt;abrodkin@synopsys.com&gt;
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As per PRM bit #0 ("D") in EXEC_CTRL enables dual-issue if set to 0,
otherwise if set to 1 all instructions are executed one at a time,
i.e. dual-issue is disabled.

Signed-off-by: Alexey Brodkin &lt;abrodkin@synopsys.com&gt;
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARCv2: boot log: updates for HS48: dual-issue, ECC, Loop Buffer</title>
<updated>2017-11-13T22:37:39+00:00</updated>
<author>
<name>Vineet Gupta</name>
<email>vgupta@synopsys.com</email>
</author>
<published>2017-11-10T20:40:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f3156851616b4f3cb1d6c567fe46adcfd43ad8f8'/>
<id>f3156851616b4f3cb1d6c567fe46adcfd43ad8f8</id>
<content type='text'>
Print the hardware support for ECC, Loop Buffer as well as the runtime
enabled status

Note that unlike the existing boot printing, this one is not read from
pre-decoded hardware capabilty info cached in cpuinfo[] struct.
Instead we read the AUX regs on the spot and print it, without botherign
to save anywhere.

There is no point in saving static hardware capabilites in memory when
its use is very sporadic and non-performance critical, mainly for
/proc/cpuinfo. This gets worse in SMP, given it is per-cpu, and pretty
much exactly same across all cpus. So only info needed at runtime
(e.g. TLB geometry) needs to be cached in cpuinfo[]. So going fwd
we will start converting code to this paradigm.

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Print the hardware support for ECC, Loop Buffer as well as the runtime
enabled status

Note that unlike the existing boot printing, this one is not read from
pre-decoded hardware capabilty info cached in cpuinfo[] struct.
Instead we read the AUX regs on the spot and print it, without botherign
to save anywhere.

There is no point in saving static hardware capabilites in memory when
its use is very sporadic and non-performance critical, mainly for
/proc/cpuinfo. This gets worse in SMP, given it is per-cpu, and pretty
much exactly same across all cpus. So only info needed at runtime
(e.g. TLB geometry) needs to be cached in cpuinfo[]. So going fwd
we will start converting code to this paradigm.

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARCv2: boot log: identify HS48 cores (dual issue)</title>
<updated>2017-10-04T03:36:49+00:00</updated>
<author>
<name>Vineet Gupta</name>
<email>vgupta@synopsys.com</email>
</author>
<published>2017-09-22T01:02:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=dea8252059a3210340f255bf69d67225b9af552d'/>
<id>dea8252059a3210340f255bf69d67225b9af552d</id>
<content type='text'>
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARC: boot log: decontaminate ARCv2 ISA_CONFIG register</title>
<updated>2017-10-04T03:36:49+00:00</updated>
<author>
<name>Vineet Gupta</name>
<email>vgupta@synopsys.com</email>
</author>
<published>2017-09-22T00:46:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=010a8c98884f4ca42a167c9b51470c624daa2932'/>
<id>010a8c98884f4ca42a167c9b51470c624daa2932</id>
<content type='text'>
ARCv2 ISA_CONFIG and ARC700_BUILD build config registers are not
compatible. cpuinfo_arc had isa info placeholder which was mashup of bits
form both.

Untangle this by defining it off of ARCv2 ISA info and it is fine even
for ARC700 since former is a super set of latter (ARC700 buildonly has 2
bits for atomics and stack check).

At runtime, we treat ARCv2 ISA info as a generic placeholder but
populate it correctly depending on ARC700 or HS.

This paves way for adding more HS specific bits in isa info which was
colliding with the extra bits for arc700.

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
ARCv2 ISA_CONFIG and ARC700_BUILD build config registers are not
compatible. cpuinfo_arc had isa info placeholder which was mashup of bits
form both.

Untangle this by defining it off of ARCv2 ISA info and it is fine even
for ARC700 since former is a super set of latter (ARC700 buildonly has 2
bits for atomics and stack check).

At runtime, we treat ARCv2 ISA info as a generic placeholder but
populate it correctly depending on ARC700 or HS.

This paves way for adding more HS specific bits in isa info which was
colliding with the extra bits for arc700.

Signed-off-by: Vineet Gupta &lt;vgupta@synopsys.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: treewide: remove GFP_TEMPORARY allocation flag</title>
<updated>2017-09-14T01:53:16+00:00</updated>
<author>
<name>Michal Hocko</name>
<email>mhocko@suse.com</email>
</author>
<published>2017-09-13T23:28:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0ee931c4e31a5efb134c76440405e9219f896e33'/>
<id>0ee931c4e31a5efb134c76440405e9219f896e33</id>
<content type='text'>
GFP_TEMPORARY was introduced by commit e12ba74d8ff3 ("Group short-lived
and reclaimable kernel allocations") along with __GFP_RECLAIMABLE.  It's
primary motivation was to allow users to tell that an allocation is
short lived and so the allocator can try to place such allocations close
together and prevent long term fragmentation.  As much as this sounds
like a reasonable semantic it becomes much less clear when to use the
highlevel GFP_TEMPORARY allocation flag.  How long is temporary? Can the
context holding that memory sleep? Can it take locks? It seems there is
no good answer for those questions.

The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
__GFP_RECLAIMABLE which in itself is tricky because basically none of
the existing caller provide a way to reclaim the allocated memory.  So
this is rather misleading and hard to evaluate for any benefits.

I have checked some random users and none of them has added the flag
with a specific justification.  I suspect most of them just copied from
other existing users and others just thought it might be a good idea to
use without any measuring.  This suggests that GFP_TEMPORARY just
motivates for cargo cult usage without any reasoning.

I believe that our gfp flags are quite complex already and especially
those with highlevel semantic should be clearly defined to prevent from
confusion and abuse.  Therefore I propose dropping GFP_TEMPORARY and
replace all existing users to simply use GFP_KERNEL.  Please note that
SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
so they will be placed properly for memory fragmentation prevention.

I can see reasons we might want some gfp flag to reflect shorterm
allocations but I propose starting from a clear semantic definition and
only then add users with proper justification.

This was been brought up before LSF this year by Matthew [1] and it
turned out that GFP_TEMPORARY really doesn't have a clear semantic.  It
seems to be a heuristic without any measured advantage for most (if not
all) its current users.  The follow up discussion has revealed that
opinions on what might be temporary allocation differ a lot between
developers.  So rather than trying to tweak existing users into a
semantic which they haven't expected I propose to simply remove the flag
and start from scratch if we really need a semantic for short term
allocations.

[1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org

[akpm@linux-foundation.org: fix typo]
[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: drm/i915: fix up]
  Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Acked-by: Mel Gorman &lt;mgorman@suse.de&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Neil Brown &lt;neilb@suse.de&gt;
Cc: "Theodore Ts'o" &lt;tytso@mit.edu&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>
GFP_TEMPORARY was introduced by commit e12ba74d8ff3 ("Group short-lived
and reclaimable kernel allocations") along with __GFP_RECLAIMABLE.  It's
primary motivation was to allow users to tell that an allocation is
short lived and so the allocator can try to place such allocations close
together and prevent long term fragmentation.  As much as this sounds
like a reasonable semantic it becomes much less clear when to use the
highlevel GFP_TEMPORARY allocation flag.  How long is temporary? Can the
context holding that memory sleep? Can it take locks? It seems there is
no good answer for those questions.

The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
__GFP_RECLAIMABLE which in itself is tricky because basically none of
the existing caller provide a way to reclaim the allocated memory.  So
this is rather misleading and hard to evaluate for any benefits.

I have checked some random users and none of them has added the flag
with a specific justification.  I suspect most of them just copied from
other existing users and others just thought it might be a good idea to
use without any measuring.  This suggests that GFP_TEMPORARY just
motivates for cargo cult usage without any reasoning.

I believe that our gfp flags are quite complex already and especially
those with highlevel semantic should be clearly defined to prevent from
confusion and abuse.  Therefore I propose dropping GFP_TEMPORARY and
replace all existing users to simply use GFP_KERNEL.  Please note that
SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
so they will be placed properly for memory fragmentation prevention.

I can see reasons we might want some gfp flag to reflect shorterm
allocations but I propose starting from a clear semantic definition and
only then add users with proper justification.

This was been brought up before LSF this year by Matthew [1] and it
turned out that GFP_TEMPORARY really doesn't have a clear semantic.  It
seems to be a heuristic without any measured advantage for most (if not
all) its current users.  The follow up discussion has revealed that
opinions on what might be temporary allocation differ a lot between
developers.  So rather than trying to tweak existing users into a
semantic which they haven't expected I propose to simply remove the flag
and start from scratch if we really need a semantic for short term
allocations.

[1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org

[akpm@linux-foundation.org: fix typo]
[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: drm/i915: fix up]
  Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Acked-by: Mel Gorman &lt;mgorman@suse.de&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Neil Brown &lt;neilb@suse.de&gt;
Cc: "Theodore Ts'o" &lt;tytso@mit.edu&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>
</feed>
