Using virtually mapped stack, kernel stacks are allocated via vmalloc.

In the current implementation, two stacks per cpu can be cached when
tasks are freed and the cached stacks are used again in task
duplications.  But the cached stacks may remain unfreed even when cpu
are offline.  By adding a cpu hotplug callback to free the cached stacks
when a cpu goes offline, the pages of the cached stacks are not wasted.

Link: http://lkml.kernel.org/r/1487076043-17802-1-git-send-email-hoeun.ryu@gmail.comSigned-off-by: NHoeun Ryu <hoeun.ryu@gmail.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Mateusz Guzik <mguzik@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Prepare to mark sensitive kernel structures for randomization by making
sure they're using designated initializers.  These were identified
during allyesconfig builds of x86, arm, and arm64, with most initializer
fixes extracted from grsecurity.

Link: http://lkml.kernel.org/r/20170329210419.GA40066@beastSigned-off-by: NKees Cook <keescook@chromium.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The current SUSPECT_CODE_INDENT test does not recognize several
defective code style defects where code following a logical test is
inappropriately indented.

Before this patch, for code like:

	if (foo)
	bar();

checkpatch would not emit a warning.

Improve the test to warn when code after a logical test has the same
indentation as the logical test.

Perform the same indentation test for "else" blocks too.

Link: http://lkml.kernel.org/r/df2374b68c4a68af2b7ef08afe486584811f610a.1493683942.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The current test works only for a single patch context as it is done in
the foreach ($rawlines) loop that precedes the loop where the actual
$context_function variable is used.

Move the set of $context_function into the foreach (@lines) loop where
it is useful for each patch context.

Link: http://lkml.kernel.org/r/6c675a31c74fbfad4fc45b9f462303d60ca2a283.1493486091.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When using checkpatch on out-of-tree code, it may occur that some
project-specific types are used, which will cause spurious warnings.
Add the --typedefsfile option as a way to extend the known types and
deal with this issue.

This was developed for OP-TEE [1].  We run a Travis job on all pull
requests [2], and checkpatch is part of that.  The typical false warning
we get on a regular basis is with some pointers to functions returning
TEE_Result [3], which is a typedef from the GlobalPlatform APIs.  We
consider it is acceptable to use GP types in the OP-TEE core
implementation, that's why this patch would be helpful for us.

[1] https://github.com/OP-TEE/optee_os
[2] https://travis-ci.org/OP-TEE/optee_os/builds
[3] https://travis-ci.org/OP-TEE/optee_os/builds/193355335#L1733

Link: http://lkml.kernel.org/r/ba1124d6dfa599bb0dd1d8919dd45dd09ce541a4.1492702192.git.jerome.forissier@linaro.orgSigned-off-by: NJerome Forissier <jerome.forissier@linaro.org>
Cc: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Find multi-line uses of k.alloc by using the $stat variable and not the
$line variable.  This can still --fix only the single line variant
though.

Link: http://lkml.kernel.org/r/3f4b23d37cd4c7d8628eefc25afe83ba8fb3ab55.1493167076.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently checkpatch.pl does not recognize git's default commit revert
message and will complain about the hash format.  Add special audit for
revert commit message line to fix it.

Link: http://lkml.kernel.org/r/20170411191532.74381-1-wvw@google.comSigned-off-by: NWei Wang <wvw@google.com>
Acked-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Try to make the conversion of embedded function names to "%s: ", __func__
a bit clearer.

Add a bit more information to the comment describing the test too.

Link: http://lkml.kernel.org/r/38f5d32f0aec1cd98cb9ceeedd6a736cc9a802db.1491759835.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The logic currrently misses macros that start with an if statement.

e.g.:    #define foo(bar)   if (bar) baz;

Add a test for macro content that starts with if

Link: http://lkml.kernel.org/r/a9d41aafe1673889caf1a9850208fb7fd74107a0.1491783914.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Reported-by: NAndreas Mohr <andi@lisas.de>
Original-patch-by: NAlfonso Lima <alfonsolimaastor@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many structs are generally used const and there is a known list of these
structs.

struct definitions should not be generally be declared const.

Add a test for the lack of an open brace immediately after the struct to
avoid definitions.

This avoids the false positive "struct foo should normally be const"
message only when the open brace is on the same line as the definition.

Link: http://lkml.kernel.org/r/0dce709150d712e66f1b90b03827634b53b28085.1491845946.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Cc: Arthur Brainville <ybalrid@ybalrid.info>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Allow a leading space and otherwise blank link in the email headers as
it can be a line wrapped Spamassassin multiple line string or any other
valid rfc 2822/5322 email header.

The line with space causes checkpatch to erroneously think that it's in
the content body, as opposed to headers and thus flag a mail header as
an unwrapped long comment line.

Link: http://lkml.kernel.org/r/d75a9f0b78b3488078429f4037d9fff3bdfa3b78.1490247180.git.joe@perches.comSigned-off-by: NJoe Perches &lt;joe@perches.com&gt;Reported-by: Darren Hart (VMware) <dvhart@infradead.org>
Tested-by: NDarren Hart (VMware) <dvhart@infradead.org>
Reviewed-by: NDarren Hart (VMware) <dvhart@vmware.com>
Original-patch-by: NJohn 'Warthog9' Hawley (VMware) <warthog9@eaglescrag.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The existing behavior relies on patch context to identify function
declarations.  Add the ability to find function declarations when there
is an open brace in column 1.

This finds function declarations only in specific single line forms
where the function name is on a single line like:

  int foo(args...)
  {

and

  int
  foo(args...)
  {

It does not recognize function declarations like:

  int foo(int bar,
          int baz)
  {

Link: http://lkml.kernel.org/r/738d74bbbe1a06b80f11ed504818107c68903095.1488155636.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

%pK was at least once misused at %pk in an out-of-tree module.  This
lead to some security concerns.  Add the ability to track single and
multiple line statements for misuses of %p<foo>.

[akpm@linux-foundation.org: add helpful comment into lib/vsprintf.c]
[akpm@linux-foundation.org: text tweak]
Link: http://lkml.kernel.org/r/163a690510e636a23187c0dc9caa09ddac6d4cde.1488228427.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Acked-by: NKees Cook <keescook@chromium.org>
Acked-by: NWilliam Roberts <william.c.roberts@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Config EXPERIMENTAL has been removed from kernel in 2013 (see commit
3d374d09: "final removal of CONFIG_EXPERIMENTAL"), there is no any
reason to do these checks now.

Link: http://lkml.kernel.org/r/1488234097-20119-1-git-send-email-ruslan.bilovol@gmail.comSigned-off-by: NRuslan Bilovol <ruslan.bilovol@gmail.com>
Acked-by: NKees Cook <keescook@chromium.org>
Acked-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If you modify the target asm we currently do not force the recompilation
of the firmware files.  The target asm is in the firmware/Makefile, peg
this file as a dependency to require re-compilation of firmware targets
when the asm changes.

Link: http://lkml.kernel.org/r/20170123150727.4883-1-mcgrof@kernel.orgSigned-off-by: NLuis R. Rodriguez <mcgrof@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <mmarek@suse.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tom Gundersen <teg@jklm.no>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Extract the linked list sorting test code into its own source file, to
allow to compile it either to a loadable module, or builtin into the
kernel.

Link: http://lkml.kernel.org/r/1488287219-15832-4-git-send-email-geert@linux-m68k.orgSigned-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Allow to compile the array-based sort test code either to a loadable
module, or builtin into the kernel.

Link: http://lkml.kernel.org/r/1488287219-15832-3-git-send-email-geert@linux-m68k.orgSigned-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "lib: add module support to sort tests".

This patch series allows to compile the array-based and linked list sort
test code either to loadable modules, or builtin into the kernel.

It's very valuable to have modular tests, so you can run them just by
insmodding the test modules, instead of needing a separate kernel that
runs them at boot.

This patch (of 3):

This reverts commit 8893f519.

It's very valuable to have modular tests, so you can run them just by
insmodding the test modules, instead of needing a separate kernel that
runs them at boot.

Link: http://lkml.kernel.org/r/1488287219-15832-2-git-send-email-geert@linux-m68k.orgSigned-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

c2port_device_register() never returns NULL, it uses error pointers.

Link: http://lkml.kernel.org/r/20170412083321.GC3250@mwanda
Fixes: 65131cd5 ("c2port: add c2port support for Eurotech Duramar 2150")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NRodolfo Giometti <giometti@linux.it>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The "DIV_ROUND_UP(size, PAGE_SIZE)" operation can overflow if "size" is
more than ULLONG_MAX - PAGE_SIZE.

Link: http://lkml.kernel.org/r/20170322111950.GA11279@mwandaSigned-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Cc: Jorgen Hansen <jhansen@vmware.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When I was running my testcase which may block hundreds of threads on fs
locks, I got lockup due to output from debug_show_all_locks() added by
commit b2d4c2ed ("locking/hung_task: Show all locks").

For example, if 1000 threads were blocked in TASK_UNINTERRUPTIBLE state
and 500 out of 1000 threads hold some lock, debug_show_all_locks() from
for_each_process_thread() loop will report locks held by 500 threads for
1000 times.  This is a too much noise.

In order to make sure rcu_lock_break() is called frequently, we should
avoid calling debug_show_all_locks() from for_each_process_thread() loop
because debug_show_all_locks() effectively calls for_each_process_thread()
loop.  Let's defer calling debug_show_all_locks() till before panic() or
leaving for_each_process_thread() loop.

Link: http://lkml.kernel.org/r/1489296834-60436-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jpSigned-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: NVegard Nossum <vegard.nossum@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a top-level Makefile help target for Userspace tools.

Also make each help "heading" end with a colon ':'.

Link: http://lkml.kernel.org/r/55c986ff-3966-3e47-2984-7349da2cce51@infradead.orgSigned-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

jiffies_64 is defined in kernel/time/timer.c with
____cacheline_aligned_in_smp, however this macro is not part of the
declaration of jiffies and jiffies_64 in jiffies.h.

As a result clang generates the following warning:

  kernel/time/timer.c:57:26: error: section does not match previous declaration [-Werror,-Wsection]
  __visible u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;
                           ^
  include/linux/cache.h:39:36: note: expanded from macro '__cacheline_aligned_in_smp'
                                     ^
  include/linux/cache.h:34:4: note: expanded from macro '__cacheline_aligned'
                   __section__(".data..cacheline_aligned")))
                   ^
  include/linux/jiffies.h:77:12: note: previous attribute is here
  extern u64 __jiffy_data jiffies_64;
             ^
  include/linux/jiffies.h:70:38: note: expanded from macro '__jiffy_data'

Link: http://lkml.kernel.org/r/20170403190200.70273-1-mka@chromium.orgSigned-off-by: NMatthias Kaehlcke <mka@chromium.org>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Cc: Grant Grundler <grundler@chromium.org>
Cc: Michael Davidson <md@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Moving from get_user_pages() to get_user_pages_unlocked() simplifies the
code and takes advantage of VM_FAULT_RETRY functionality when faulting
in pages.

Link: http://lkml.kernel.org/r/20161101194332.23961-1-lstoakes@gmail.comSigned-off-by: NLorenzo Stoakes <lstoakes@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Mihai Caraman <mihai.caraman@freescale.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

do_proc_dointvec_jiffies_conv() uses LONG_MAX/HZ as the max value to
avoid overflow.  But actually the *valp is int type, so it still causes
overflow.

For example,

  echo 2147483647 > ./sys/net/ipv4/tcp_keepalive_time

Then,

  cat ./sys/net/ipv4/tcp_keepalive_time

The output is "-1", it is not expected.

Now use INT_MAX/HZ as the max value instead LONG_MAX/HZ to fix it.

Link: http://lkml.kernel.org/r/1490109532-9228-1-git-send-email-fgao@ikuai8.comSigned-off-by: NGao Feng <fgao@ikuai8.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Coccinelle emits this warning:

  WARNING: casting value returned by memory allocation function to (struct proc_inode *) is useless.

Remove unnecessary cast.

Link: http://lkml.kernel.org/r/1487745720-16967-1-git-send-email-me@tobin.ccSigned-off-by: NTobin C. Harding <me@tobin.cc>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The main goal of direct compaction is to form a high-order page for
allocation, but it should also help against long-term fragmentation when
possible.

Most lower-than-pageblock-order compactions are for non-movable
allocations, which means that if we compact in a movable pageblock and
terminate as soon as we create the high-order page, it's unlikely that
the fallback heuristics will claim the whole block.  Instead there might
be a single unmovable page in a pageblock full of movable pages, and the
next unmovable allocation might pick another pageblock and increase
long-term fragmentation.

To help against such scenarios, this patch changes the termination
criteria for compaction so that the current pageblock is finished even
though the high-order page already exists.  Note that it might be
possible that the high-order page formed elsewhere in the zone due to
parallel activity, but this patch doesn't try to detect that.

This is only done with sync compaction, because async compaction is
limited to pageblock of the same migratetype, where it cannot result in
a migratetype fallback.  (Async compaction also eagerly skips
order-aligned blocks where isolation fails, which is against the goal of
migrating away as much of the pageblock as possible.)

As a result of this patch, long-term memory fragmentation should be
reduced.

In testing based on 4.9 kernel with stress-highalloc from mmtests
configured for order-4 GFP_KERNEL allocations, this patch has reduced
the number of unmovable allocations falling back to movable pageblocks
by 20%.  The number

Link: http://lkml.kernel.org/r/20170307131545.28577-9-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The migrate scanner in async compaction is currently limited to
MIGRATE_MOVABLE pageblocks.  This is a heuristic intended to reduce
latency, based on the assumption that non-MOVABLE pageblocks are
unlikely to contain movable pages.

However, with the exception of THP's, most high-order allocations are
not movable.  Should the async compaction succeed, this increases the
chance that the non-MOVABLE allocations will fallback to a MOVABLE
pageblock, making the long-term fragmentation worse.

This patch attempts to help the situation by changing async direct
compaction so that the migrate scanner only scans the pageblocks of the
requested migratetype.  If it's a non-MOVABLE type and there are such
pageblocks that do contain movable pages, chances are that the
allocation can succeed within one of such pageblocks, removing the need
for a fallback.  If that fails, the subsequent sync attempt will ignore
this restriction.

In testing based on 4.9 kernel with stress-highalloc from mmtests
configured for order-4 GFP_KERNEL allocations, this patch has reduced
the number of unmovable allocations falling back to movable pageblocks
by 30%.  The number of movable allocations falling back is reduced by
12%.

Link: http://lkml.kernel.org/r/20170307131545.28577-8-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Preparation patch.  We are going to need migratetype at lower layers
than compact_zone() and compact_finished().

Link: http://lkml.kernel.org/r/20170307131545.28577-7-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Preparation for making the decisions more complex and depending on
compact_control flags.  No functional change.

Link: http://lkml.kernel.org/r/20170307131545.28577-6-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When stealing pages from pageblock of a different migratetype, we count
how many free pages were stolen, and change the pageblock's migratetype
if more than half of the pageblock was free.  This might be too
conservative, as there might be other pages that are not free, but were
allocated with the same migratetype as our allocation requested.

While we cannot determine the migratetype of allocated pages precisely
(at least without the page_owner functionality enabled), we can count
pages that compaction would try to isolate for migration - those are
either on LRU or __PageMovable().  The rest can be assumed to be
MIGRATE_RECLAIMABLE or MIGRATE_UNMOVABLE, which we cannot easily
distinguish.  This counting can be done as part of free page stealing
with little additional overhead.

The page stealing code is changed so that it considers free pages plus
pages of the "good" migratetype for the decision whether to change
pageblock's migratetype.

The result should be more accurate migratetype of pageblocks wrt the
actual pages in the pageblocks, when stealing from semi-occupied
pageblocks.  This should help the efficiency of page grouping by
mobility.

In testing based on 4.9 kernel with stress-highalloc from mmtests
configured for order-4 GFP_KERNEL allocations, this patch has reduced
the number of unmovable allocations falling back to movable pageblocks
by 47%.  The number of movable allocations falling back to other
pageblocks are increased by 55%, but these events don't cause permanent
fragmentation, so the tradeoff should be positive.  Later patches also
offset the movable fallback increase to some extent.

[akpm@linux-foundation.org: merge fix]
Link: http://lkml.kernel.org/r/20170307131545.28577-5-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The __rmqueue_fallback() function is called when there's no free page of
requested migratetype, and we need to steal from a different one.

There are various heuristics to make this event infrequent and reduce
permanent fragmentation.  The main one is to try stealing from a
pageblock that has the most free pages, and possibly steal them all at
once and convert the whole pageblock.  Precise searching for such
pageblock would be expensive, so instead the heuristics walks the free
lists from MAX_ORDER down to requested order and assumes that the block
with highest-order free page is likely to also have the most free pages
in total.

Chances are that together with the highest-order page, we steal also
pages of lower orders from the same block.  But then we still split the
highest order page.  This is wasteful and can contribute to
fragmentation instead of avoiding it.

This patch thus changes __rmqueue_fallback() to just steal the page(s)
and put them on the freelist of the requested migratetype, and only
report whether it was successful.  Then we pick (and eventually split)
the smallest page with __rmqueue_smallest().  This all happens under
zone lock, so nobody can steal it from us in the process.  This should
reduce fragmentation due to fallbacks.  At worst we are only stealing a
single highest-order page and waste some cycles by moving it between
lists and then removing it, but fallback is not exactly hot path so that
should not be a concern.  As a side benefit the patch removes some
duplicate code by reusing __rmqueue_smallest().

[vbabka@suse.cz: fix endless loop in the modified __rmqueue()]
  Link: http://lkml.kernel.org/r/59d71b35-d556-4fc9-ee2e-1574259282fd@suse.cz
Link: http://lkml.kernel.org/r/20170307131545.28577-4-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When detecting whether compaction has succeeded in forming a high-order
page, __compact_finished() employs a watermark check, followed by an own
search for a suitable page in the freelists.  This is not ideal for two
reasons:

 - The watermark check also searches high-order freelists, but has a
   less strict criteria wrt fallback. It's therefore redundant and waste
   of cycles. This was different in the past when high-order watermark
   check attempted to apply reserves to high-order pages.

 - The watermark check might actually fail due to lack of order-0 pages.
   Compaction can't help with that, so there's no point in continuing
   because of that. It's possible that high-order page still exists and
   it terminates.

This patch therefore removes the watermark check.  This should save some
cycles and terminate compaction sooner in some cases.

Link: http://lkml.kernel.org/r/20170307131545.28577-3-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "try to reduce fragmenting fallbacks", v3.

Last year, Johannes Weiner has reported a regression in page mobility
grouping [1] and while the exact cause was not found, I've come up with
some ways to improve it by reducing the number of allocations falling
back to different migratetype and causing permanent fragmentation.

The series was tested with mmtests stress-highalloc modified to do
GFP_KERNEL order-4 allocations, on 4.9 with "mm, vmscan: fix zone
balance check in prepare_kswapd_sleep" (without that, kcompactd indeed
wasn't woken up) on UMA machine with 4GB memory.  There were 5 repeats
of each run, as the extfrag stats are quite volatile (note the stats
below are sums, not averages, as it was less perl hacking for me).

Success rate are the same, already high due to the low allocation order
used, so I'm not including them.

Compaction stats:
(the patches are stacked, and I haven't measured the non-functional-changes
patches separately)

                                     patch 1     patch 2     patch 3     patch 4     patch 7     patch 8
  Compaction stalls                    22449       24680       24846       19765       22059       17480
  Compaction success                   12971       14836       14608       10475       11632        8757
  Compaction failures                   9477        9843       10238        9290       10426        8722
  Page migrate success               3109022     3370438     3312164     1695105     1608435     2111379
  Page migrate failure                911588     1149065     1028264     1112675     1077251     1026367
  Compaction pages isolated          7242983     8015530     7782467     4629063     4402787     5377665
  Compaction migrate scanned       980838938   987367943   957690188   917647238   947155598  1018922197
  Compaction free scanned          557926893   598946443   602236894   594024490   541169699   763651731
  Compaction cost                      10243       10578       10304        8286        8398        9440

Compaction stats are mostly within noise until patch 4, which decreases
the number of compactions, and migrations.  Part of that could be due to
more pageblocks marked as unmovable, and async compaction skipping
those.  This changes a bit with patch 7, but not so much.  Patch 8
increases free scanner stats and migrations, which comes from the
changed termination criteria.  Interestingly number of compactions
decreases - probably the fully compacted pageblock satisfies multiple
subsequent allocations, so it amortizes.

Next comes the extfrag tracepoint, where "fragmenting" means that an
allocation had to fallback to a pageblock of another migratetype which
wasn't fully free (which is almost all of the fallbacks).  I have
locally added another tracepoint for "Page steal" into
steal_suitable_fallback() which triggers in situations where we are
allowed to do move_freepages_block().  If we decide to also do
set_pageblock_migratetype(), it's "Pages steal with pageblock" with
break down for which allocation migratetype we are stealing and from
which fallback migratetype.  The last part "due to counting" comes from
patch 4 and counts the events where the counting of movable pages
allowed us to change pageblock's migratetype, while the number of free
pages alone wouldn't be enough to cross the threshold.

                                                       patch 1     patch 2     patch 3     patch 4     patch 7     patch 8
  Page alloc extfrag event                            10155066     8522968    10164959    15622080    13727068    13140319
  Extfrag fragmenting                                 10149231     8517025    10159040    15616925    13721391    13134792
  Extfrag fragmenting for unmovable                     159504      168500      184177       97835       70625       56948
  Extfrag fragmenting unmovable placed with movable     153613      163549      172693       91740       64099       50917
  Extfrag fragmenting unmovable placed with reclaim.      5891        4951       11484        6095        6526        6031
  Extfrag fragmenting for reclaimable                     4738        4829        6345        4822        5640        5378
  Extfrag fragmenting reclaimable placed with movable     1836        1902        1851        1579        1739        1760
  Extfrag fragmenting reclaimable placed with unmov.      2902        2927        4494        3243        3901        3618
  Extfrag fragmenting for movable                      9984989     8343696     9968518    15514268    13645126    13072466
  Pages steal                                           179954      192291      210880      123254       94545       81486
  Pages steal with pageblock                             22153       18943       20154       33562       29969       33444
  Pages steal with pageblock for unmovable               14350       12858       13256       20660       19003       20852
  Pages steal with pageblock for unmovable from mov.     12812       11402       11683       19072       17467       19298
  Pages steal with pageblock for unmovable from recl.     1538        1456        1573        1588        1536        1554
  Pages steal with pageblock for movable                  7114        5489        5965       11787       10012       11493
  Pages steal with pageblock for movable from unmov.      6885        5291        5541       11179        9525       10885
  Pages steal with pageblock for movable from recl.        229         198         424         608         487         608
  Pages steal with pageblock for reclaimable               689         596         933        1115         954        1099
  Pages steal with pageblock for reclaimable from unmov.   273         219         537         658         547         667
  Pages steal with pageblock for reclaimable from mov.     416         377         396         457         407         432
  Pages steal with pageblock due to counting                                                 11834       10075        7530
  ... for unmovable                                                                           8993        7381        4616
  ... for movable                                                                             2792        2653        2851
  ... for reclaimable                                                                           49          41          63

What we can see is that "Extfrag fragmenting for unmovable" and "...
placed with movable" drops with almost each patch, which is good as we
are polluting less movable pageblocks with unmovable pages.

The most significant change is patch 4 with movable page counting.  On
the other hand it increases "Extfrag fragmenting for movable" by 50%.
"Pages steal" drops though, so these movable allocation fallbacks find
only small free pages and are not allowed to steal whole pageblocks
back.  "Pages steal with pageblock" raises, because the patch increases
the chances of pageblock migratetype changes to happen.  This affects
all migratetypes.

The summary is that patch 4 is not a clear win wrt these stats, but I
believe that the tradeoff it makes is a good one.  There's less
pollution of movable pageblocks by unmovable allocations.  There's less
stealing between pageblock, and those that remain have higher chance of
changing migratetype also the pageblock itself, so it should more
faithfully reflect the migratetype of the pages within the pageblock.
The increase of movable allocations falling back to unmovable pageblock
might look dramatic, but those allocations can be migrated by compaction
when needed, and other patches in the series (7-9) improve that aspect.

Patches 7 and 8 continue the trend of reduced unmovable fallbacks and
also reduce the impact on movable fallbacks from patch 4.

[1] https://www.spinics.net/lists/linux-mm/msg114237.html

This patch (of 8):

While currently there are (mostly by accident) no holes in struct
compact_control (on x86_64), but we are going to add more bool flags, so
place them all together to the end of the structure.  While at it, just
order all fields from largest to smallest.

Link: http://lkml.kernel.org/r/20170307131545.28577-2-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 37d69ee3 ("docs: bump minimal GNU Make version to 3.81")
changes one entry of GNU make version in the changes.rst, there's still
one more entry saying that one need version 3.80.  Fix that.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull cifs fixes from Steve French:
 "Various fixes for stable for CIFS/SMB3 especially for better
  interoperability for SMB3 to Macs.

  It also includes Pavel's improvements to SMB3 async i/o support
  (which is much faster now)"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: add misssing SFM mapping for doublequote
  SMB3: Work around mount failure when using SMB3 dialect to Macs
  cifs: fix CIFS_IOC_GET_MNT_INFO oops
  CIFS: fix mapping of SFM_SPACE and SFM_PERIOD
  CIFS: fix oplock break deadlocks
  cifs: fix CIFS_ENUMERATE_SNAPSHOTS oops
  cifs: fix leak in FSCTL_ENUM_SNAPS response handling
  Set unicode flag on cifs echo request to avoid Mac error
  CIFS: Add asynchronous write support through kernel AIO
  CIFS: Add asynchronous read support through kernel AIO
  CIFS: Add asynchronous context to support kernel AIO
  cifs: fix IPv6 link local, with scope id, address parsing
  cifs: small underflow in cnvrtDosUnixTm()

Pull xfs updates from Darrick Wong:
 "Here are the XFS changes for 4.12. The big new feature for this
  release is the new space mapping ioctl that we've been discussing
  since LSF2016, but other than that most of the patches are larger bug
  fixes, memory corruption prevention, and other cleanups.

  Summary:
   - various code cleanups
   - introduce GETFSMAP ioctl
   - various refactoring
   - avoid dio reads past eof
   - fix memory corruption and other errors with fragmented directory blocks
   - fix accidental userspace memory corruptions
   - publish fs uuid in superblock
   - make fstrim terminatable
   - fix race between quotaoff and in-core inode creation
   - avoid use-after-free when finishing up w/ buffer heads
   - reserve enough space to handle bmap tree resizing during cow remap"

* tag 'xfs-4.12-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (53 commits)
  xfs: fix use-after-free in xfs_finish_page_writeback
  xfs: reserve enough blocks to handle btree splits when remapping
  xfs: wait on new inodes during quotaoff dquot release
  xfs: update ag iterator to support wait on new inodes
  xfs: support ability to wait on new inodes
  xfs: publish UUID in struct super_block
  xfs: Allow user to kill fstrim process
  xfs: better log intent item refcount checking
  xfs: fix up quotacheck buffer list error handling
  xfs: remove xfs_trans_ail_delete_bulk
  xfs: don't use bool values in trace buffers
  xfs: fix getfsmap userspace memory corruption while setting OF_LAST
  xfs: fix __user annotations for xfs_ioc_getfsmap
  xfs: corruption needs to respect endianess too!
  xfs: use NULL instead of 0 to initialize a pointer in xfs_ioc_getfsmap
  xfs: use NULL instead of 0 to initialize a pointer in xfs_getfsmap
  xfs: simplify validation of the unwritten extent bit
  xfs: remove unused values from xfs_exntst_t
  xfs: remove the unused XFS_MAXLINK_1 define
  xfs: more do_div cleanups
  ...

Pull block fixes and updates from Jens Axboe:
 "Some fixes and followup features/changes that should go in, in this
  merge window. This contains:

   - Two fixes for lightnvm from Javier, fixing problems in the new code
     merge previously in this merge window.

   - A fix from Jan for the backing device changes, fixing an issue in
     NFS that causes a failure to mount on certain setups.

   - A change from Christoph, cleaning up the blk-mq init and exit
     request paths.

   - Remove elevator_change(), which is now unused. From Bart.

   - A fix for queue operation invocation on a dead queue, from Bart.

   - A series fixing up mtip32xx for blk-mq scheduling, removing a
     bandaid we previously had in place for this. From me.

   - A regression fix for this series, fixing a case where we wait on
     workqueue flushing from an invalid (non-blocking) context. From me.

   - A fix/optimization from Ming, ensuring that we don't both quiesce
     and freeze a queue at the same time.

   - A fix from Peter on lock ordering for CPU hotplug. Not a real
     problem right now, but will be once the CPU hotplug rework goes in.

   - A series from Omar, cleaning up out blk-mq debugfs support, and
     adding support for exporting info from schedulers in debugfs as
     well. This is really useful in debugging stalls or livelocks. From
     Omar"

* 'for-linus' of git://git.kernel.dk/linux-block: (28 commits)
  mq-deadline: add debugfs attributes
  kyber: add debugfs attributes
  blk-mq-debugfs: allow schedulers to register debugfs attributes
  blk-mq: untangle debugfs and sysfs
  blk-mq: move debugfs declarations to a separate header file
  blk-mq: Do not invoke queue operations on a dead queue
  blk-mq-debugfs: get rid of a bunch of boilerplate
  blk-mq-debugfs: rename hw queue directories from <n> to hctx<n>
  blk-mq-debugfs: don't open code strstrip()
  blk-mq-debugfs: error on long write to queue "state" file
  blk-mq-debugfs: clean up flag definitions
  blk-mq-debugfs: separate flags with |
  nfs: Fix bdi handling for cloned superblocks
  block/mq: Cure cpu hotplug lock inversion
  lightnvm: fix bad back free on error path
  lightnvm: create cmd before allocating request
  blk-mq: don't use sync workqueue flushing from drivers
  mtip32xx: convert internal commands to regular block infrastructure
  mtip32xx: cleanup internal tag assumptions
  block: don't call blk_mq_quiesce_queue() after queue is frozen
  ...

Now that kref is using the refcount apis, the _GPL markings are getting
exported to places that it previously wasn't.  Now kref.h is GPLv2
licensed, so any non-GPL code using it better be talking to some
lawyers, but changing api markings isn't considered "nice", so let's fix
this up.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since 2014, you can't successfully build kernels with GNU Make version
3.80. Example errors:

  $ git describe
  v4.11
  $ make --version | head -1
  GNU Make 3.80
  $ make defconfig
    HOSTCC  scripts/basic/fixdep
  scripts/Makefile.host:135: *** missing separator.  Stop.
  make: *** [defconfig] Error 2
  $ make ARCH=arm64 help
  arch/arm64/Makefile:43: *** unterminated call to function `warning': missing `)'.  Stop.
  $ make help >/dev/null
  ./Documentation/Makefile.sphinx:25: Extraneous text after `else' directive
  ./Documentation/Makefile.sphinx:31: *** only one `else' per conditional.  Stop.
  make: *** [help] Error 2

The first breakage was introduced by commit c8589d1e ("kbuild:
handle multi-objs dependency appropriately").  Since then (i.e. v3.18),
GNU Make 3.80 has not been able to compile the kernel, but nobody has
ever complained aboutt (or noticed) it.

Even GNU Make 3.81 is more than 10 years old.  It would not hurt to
match the documentation with reality instead of fixing makefiles.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>