Replace bootmem allocator with memblock and enable use of NO_BOOTMEM like
on most other architectures.

Alpha gets the description of the physical memory from the firmware as an
array of memory clusters.  Each cluster that is not reserved by the
firmware is added to memblock.memory.

Once the memblock.memory is set up, we reserve the kernel and initrd pages
with memblock reserve.

Since we don't need the bootmem bitmap anymore, the code that finds an
appropriate place is removed.

The conversion does not take care of NUMA support which is marked broken
for more than 10 years now.

Link: http://lkml.kernel.org/r/1535952894-10967-1-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The unicore32 architecture already supports memblock and uses it for some
early memory reservations, e.g initrd and the page tables.

At some point unicore32 allocates the bootmem bitmap from the memblock and
then hands over the memory reservations from memblock to bootmem.

This patch removes the bootmem initialization and leaves memblock as the
only boot time memory manager for unicore32.

Link: http://lkml.kernel.org/r/1533326330-31677-8-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: NGuan Xuetao <gxt@pku.edu.cn>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rob Herring <robh@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace bootmem initialization with memblock_add and memblock_reserve calls
and explicit initialization of {min,max}_low_pfn.

Link: http://lkml.kernel.org/r/1533326330-31677-7-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: NRichard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The setup_physmem() function receives uml_physmem and uml_reserved as
parameters and still used these global variables.  Replace such usage with
local variables.

Link: http://lkml.kernel.org/r/1533326330-31677-6-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: NRichard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove bootmem bitmap initialization and replace reserve_bootmem() with
memblock_reserve().

Link: http://lkml.kernel.org/r/1533326330-31677-5-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: NLey Foon Tan <ley.foon.tan@intel.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rob Herring <robh@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

All we have to do is to enable memblock, the generic FDT code will take
care of the rest.

Link: http://lkml.kernel.org/r/1533326330-31677-4-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: NLey Foon Tan <ley.foon.tan@intel.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rob Herring <robh@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Memory region size is rounded down to page boundary and with sub-page
region it becomes 0 and there is no point to add an empty region.
Moreover, when the base is less than PAGE_SIZE we get a bogus size as
(base + size - 1) evaluates to -1.

8cccffc5 ("of: check for size < 0 after rounding in
early_init_dt_add_memory_arch") introduced a test for wrap around for the
case when base is not page aligned, the same test can be used to ignore
sub-page region sizes.

Link: http://lkml.kernel.org/r/1533326330-31677-3-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "switch several architectures NO_BOOTMEM".

These patches perform conversion to NO_BOOTMEM of hexagon, nios2, uml and
unicore32.

This patch (of 7):

Add registration of the system memory with memblock, eliminate bootmem
initialization and convert early memory reservations from bootmem to
memblock.

Link: http://lkml.kernel.org/r/1533326330-31677-2-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: NRichard Kuo <rkuo@codeaurora.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rob Herring <robh@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

All callers convert its errno into a vm_fault_t, so convert it to return a
vm_fault_t directly.

Link: http://lkml.kernel.org/r/20180828145728.11873-11-willy@infradead.orgSigned-off-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Souptick Joarder <jrdr.linux@gmail.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>

Both of its callers currently convert its errno return into a vm_fault_t,
so move the conversion into __vm_insert_mixed().

Link: http://lkml.kernel.org/r/20180828145728.11873-10-willy@infradead.orgSigned-off-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Souptick Joarder <jrdr.linux@gmail.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>

vm_insert_pfn_prot() is only called from vmf_insert_pfn_prot(), so inline
it and convert some of the errnos into vm_fault codes earlier.

Link: http://lkml.kernel.org/r/20180828145728.11873-9-willy@infradead.orgSigned-off-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Souptick Joarder <jrdr.linux@gmail.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>

All callers are now converted to vmf_insert_pfn() so convert
vmf_insert_pfn() from being a compatibility wrapper around vm_insert_pfn()
to being a compatibility wrapper around vmf_insert_pfn_prot().

Link: http://lkml.kernel.org/r/20180828145728.11873-8-willy@infradead.orgSigned-off-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Souptick Joarder <jrdr.linux@gmail.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>

Documentation and comments.

Link: http://lkml.kernel.org/r/20180828145728.11873-7-willy@infradead.orgSigned-off-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Souptick Joarder <jrdr.linux@gmail.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>

Now this is no longer used outside mm/memory.c, make it static.

Link: http://lkml.kernel.org/r/20180828145728.11873-6-willy@infradead.orgSigned-off-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Souptick Joarder <jrdr.linux@gmail.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>

Return vm_fault_t codes directly from the appropriate mm routines instead
of converting from errnos ourselves.  Fixes a minor bug where we'd return
SIGBUS instead of the correct OOM code if we ran out of memory allocating
page tables.

Link: http://lkml.kernel.org/r/20180828145728.11873-5-willy@infradead.orgSigned-off-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Like vm_insert_pfn_prot(), but returns a vm_fault_t instead of an errno.
Also unexport vm_insert_pfn_prot as it has no modular users.

Link: http://lkml.kernel.org/r/20180828145728.11873-4-willy@infradead.orgSigned-off-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Souptick Joarder <jrdr.linux@gmail.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>

All callers are now converted to vmf_insert_mixed() so convert
vmf_insert_mixed() from being a compatibility wrapper into the real
function.

Link: http://lkml.kernel.org/r/20180828145728.11873-3-willy@infradead.orgSigned-off-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Souptick Joarder <jrdr.linux@gmail.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>

cramfs is the only remaining user of vm_insert_mixed() and should be
converted to vmf_insert_mixed().

Based on a previous patch from Matthew Wilcox.

Link: http://lkml.kernel.org/r/nycvar.YSQ.7.76.1808290945450.10215@knanqh.ubzrSigned-off-by: NNicolas Pitre <nico@linaro.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>a
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As part of vm_fault_t conversion filemap_page_mkwrite() for the NOMMU case
was missed.  Now converted.

Link: http://lkml.kernel.org/r/20180828174952.GA29229@jordon-HP-15-Notebook-PCSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

check_for_memory() looks a bit confusing.  First of all, we have this:

if (N_MEMORY == N_NORMAL_MEMORY)
	return;

Checking the ENUM declaration, looks like N_MEMORY canot be equal to
N_NORMAL_MEMORY.

I could not find where N_MEMORY is set to N_NORMAL_MEMORY, or the other
way around either, so unless I am missing something, this condition will
never evaluate to true.  It makes sense to get rid of it.

Moving forward, the operations within the loop look a bit confusing as
well.

We set N_HIGH_MEMORY unconditionally, and then we set N_NORMAL_MEMORY in
case we have CONFIG_HIGHMEM (N_NORMAL_MEMORY != N_HIGH_MEMORY) and zone <=
ZONE_NORMAL.  (N_HIGH_MEMORY falls back to N_NORMAL_MEMORY on
!CONFIG_HIGHMEM systems, and that is why we can just go ahead and set
N_HIGH_MEMORY unconditionally)

Although this works, it is a bit subtle.

I think that this could be easier to follow:

First, we should only set N_HIGH_MEMORY in case we have CONFIG_HIGHMEM.
And then we should set N_NORMAL_MEMORY in case zone <= ZONE_NORMAL,
without further checking whether we have CONFIG_HIGHMEM or not.

Link: http://lkml.kernel.org/r/20180828210158.4617-1-osalvador@techadventures.netSigned-off-by: NOscar Salvador <osalvador@suse.de>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Michael Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

si->swap_map[] of the swap entries in cluster needs to be cleared during
freeing.  Previously, this is done in the caller of swap_free_cluster().
This may cause code duplication (one user now, will add more users later)
and lock/unlock cluster unnecessarily.  In this patch, the clearing code
is moved to swap_free_cluster() to avoid the downside.

Link: http://lkml.kernel.org/r/20180827075535.17406-4-ying.huang@intel.comSigned-off-by: N"Huang, Ying" <ying.huang@intel.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is a code cleanup patch without functionality change.

Originally, when __swap_entry_free() is called, and its return value is 0,
free_swap_slot() will always be called to free the swap entry to the
per-CPU pool.  So move the call to free_swap_slot() to __swap_entry_free()
to simplify the code.

Link: http://lkml.kernel.org/r/20180827075535.17406-3-ying.huang@intel.comSigned-off-by: N"Huang, Ying" <ying.huang@intel.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The code path to reclaim the swap entry in free_swap_and_cache() is
almost same as that of __try_to_reclaim_swap().  The largest
difference is just coding style.  So the support to the additional
requirement of free_swap_and_cache() is added into
__try_to_reclaim_swap().  free_swap_and_cache() is changed to call
__try_to_reclaim_swap(), and delete the duplicated code.  This will
improve code readability and reduce the potential bugs.

There are 2 functionality differences between __try_to_reclaim_swap()
and swap entry reclaim code of free_swap_and_cache().

- free_swap_and_cache() only reclaims the swap entry if the page is
  unmapped or swap is getting full.  The support has been added into
  __try_to_reclaim_swap().

- try_to_free_swap() (called by __try_to_reclaim_swap()) checks
  pm_suspended_storage(), while free_swap_and_cache() not.  I think
  this is OK.  Because the page and the swap entry can be reclaimed
  later eventually.

Link: http://lkml.kernel.org/r/20180827075535.17406-2-ying.huang@intel.comSigned-off-by: N"Huang, Ying" <ying.huang@intel.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, kmemleak only prints the number of suspected leaks to dmesg but
requires the user to read a debugfs file to get the actual stack traces of
the objects' allocation points.  Add a module option to print the full
object information to dmesg too.  It can be enabled with
kmemleak.verbose=1 on the kernel command line, or "echo 1 >
/sys/module/kmemleak/parameters/verbose":

This allows easier integration of kmemleak into test systems: We have
automated test infrastructure to test our Linux systems.  With this
option, running our tests with kmemleak is as simple as enabling kmemleak
and passing this command line option; the test infrastructure knows how to
save kernel logs, which will now include kmemleak reports.  Without this
option, the test infrastructure needs to be specifically taught to read
out the kmemleak debugfs file.  Removing this need for special handling
makes kmemleak more similar to other kernel debug options (slab debugging,
debug objects, etc).

Link: http://lkml.kernel.org/r/20180903144046.21023-1-vincent.whitchurch@axis.comSigned-off-by: NVincent Whitchurch <vincent.whitchurch@axis.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Revert 5ff7091f ("mm, mmu_notifier: annotate mmu notifiers with
blockable invalidate callbacks").

MMU_INVALIDATE_DOES_NOT_BLOCK flags was the only one used and it is no
longer needed since 93065ac7 ("mm, oom: distinguish blockable mode for
mmu notifiers").  We now have a full support for per range !blocking
behavior so we can drop the stop gap workaround which the per notifier
flag was used for.

Link: http://lkml.kernel.org/r/20180827112623.8992-4-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If invalidate_range_start() is called for !blocking mode then all
callbacks have to guarantee they will no block/sleep.  The same obviously
applies to invalidate_range_end because this operation pairs with the
former and they are called from the same context.  Make sure this is
appropriately documented.

Link: http://lkml.kernel.org/r/20180827112623.8992-3-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NJerome Glisse <jglisse@redhat.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Tetsuo Handa has reported that it is possible to bypass the short sleep
for PF_WQ_WORKER threads which was introduced by commit 373ccbe5
("mm, vmstat: allow WQ concurrency to discover memory reclaim doesn't make
any progress") and lock up the system if OOM.

The primary reason is that WQ_MEM_RECLAIM WQs are not guaranteed to run
even when they have a rescuer available.  Those workers might be essential
for reclaim to make a forward progress, however.  If we are too unlucky
all the allocations requests can get stuck waiting for a WQ_MEM_RECLAIM
work item and the system is essentially stuck in an OOM condition without
much hope to move on.  Tetsuo has seen the reclaim stuck on
drain_local_pages_wq or xlog_cil_push_work (xfs).  There might be others.

Since should_reclaim_retry() should be a natural reschedule point,
let's do the short sleep for PF_WQ_WORKER threads unconditionally in
order to guarantee that other pending work items are started.  This
will workaround this problem and it is less fragile than hunting down
when the sleep is missed.  Having a single sleeping point is more
robust.

[akpm@linux-foundation.org: reflow comment to 80 cols to save a couple of lines]
Link: http://lkml.kernel.org/r/20180827135101.15700-1-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Debugged-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I've noticed, that dying memory cgroups are often pinned in memory by a
single pagecache page.  Even under moderate memory pressure they sometimes
stayed in such state for a long time.  That looked strange.

My investigation showed that the problem is caused by applying the LRU
pressure balancing math:

  scan = div64_u64(scan * fraction[lru], denominator),

where

  denominator = fraction[anon] + fraction[file] + 1.

Because fraction[lru] is always less than denominator, if the initial scan
size is 1, the result is always 0.

This means the last page is not scanned and has
no chances to be reclaimed.

Fix this by rounding up the result of the division.

In practice this change significantly improves the speed of dying cgroups
reclaim.

[guro@fb.com: prevent double calculation of DIV64_U64_ROUND_UP() arguments]
  Link: http://lkml.kernel.org/r/20180829213311.GA13501@castle
Link: http://lkml.kernel.org/r/20180827162621.30187-3-guro@fb.comSigned-off-by: NRoman Gushchin <guro@fb.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Memcg charge is batched using per-cpu stocks, so an offline memcg can be
pinned by a cached charge up to a moment, when a process belonging to some
other cgroup will charge some memory on the same cpu.  In other words,
cached charges can prevent a memory cgroup from being reclaimed for some
time, without any clear need.

Let's optimize it by explicit draining of all stocks on css offlining.  As
draining is performed asynchronously, and is skipped if any parallel
draining is happening, it's cheap.

Link: http://lkml.kernel.org/r/20180827162621.30187-2-guro@fb.comSigned-off-by: NRoman Gushchin <guro@fb.com>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Acked-by: NMichal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If CONFIG_VMAP_STACK is set, kernel stacks are allocated using
__vmalloc_node_range() with __GFP_ACCOUNT.  So kernel stack pages are
charged against corresponding memory cgroups on allocation and uncharged
on releasing them.

The problem is that we do cache kernel stacks in small per-cpu caches and
do reuse them for new tasks, which can belong to different memory cgroups.

Each stack page still holds a reference to the original cgroup, so the
cgroup can't be released until the vmap area is released.

To make this happen we need more than two subsequent exits without forks
in between on the current cpu, which makes it very unlikely to happen.  As
a result, I saw a significant number of dying cgroups (in theory, up to 2
* number_of_cpu + number_of_tasks), which can't be released even by
significant memory pressure.

As a cgroup structure can take a significant amount of memory (first of
all, per-cpu data like memcg statistics), it leads to a noticeable waste
of memory.

Link: http://lkml.kernel.org/r/20180827162621.30187-1-guro@fb.com
Fixes: ac496bf4 ("fork: Optimize task creation by caching two thread stacks per CPU if CONFIG_VMAP_STACK=y")
Signed-off-by: NRoman Gushchin <guro@fb.com>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Acked-by: NMichal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Extend the slub_debug syntax to "slub_debug=<flags>[,<slub>]*", where
<slub> may contain an asterisk at the end.  For example, the following
would poison all kmalloc slabs:

	slub_debug=P,kmalloc*

and the following would apply the default flags to all kmalloc and all
block IO slabs:

	slub_debug=,bio*,kmalloc*

Please note that a similar patch was posted by Iliyan Malchev some time
ago but was never merged:

	https://marc.info/?l=linux-mm&m=131283905330474&w=2

Link: http://lkml.kernel.org/r/20180928111139.27962-1-atomlin@redhat.comSigned-off-by: NAaron Tomlin <atomlin@redhat.com>
Acked-by: NChristoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Iliyan Malchev <malchev@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Slub does not call kmalloc_slab() for sizes > KMALLOC_MAX_CACHE_SIZE,
instead it falls back to kmalloc_large().

For slab KMALLOC_MAX_CACHE_SIZE == KMALLOC_MAX_SIZE and it calls
kmalloc_slab() for all allocations relying on NULL return value for
over-sized allocations.

This inconsistency leads to unwanted warnings from kmalloc_slab() for
over-sized allocations for slab.  Returning NULL for failed allocations is
the expected behavior.

Make slub and slab code consistent by checking size >
KMALLOC_MAX_CACHE_SIZE in slab before calling kmalloc_slab().

While we are here also fix the check in kmalloc_slab().  We should check
against KMALLOC_MAX_CACHE_SIZE rather than KMALLOC_MAX_SIZE.  It all kinda
worked because for slab the constants are the same, and slub always checks
the size against KMALLOC_MAX_CACHE_SIZE before kmalloc_slab().  But if we
get there with size > KMALLOC_MAX_CACHE_SIZE anyhow bad things will
happen.  For example, in case of a newly introduced bug in slub code.

Also move the check in kmalloc_slab() from function entry to the size >
192 case.  This partially compensates for the additional check in slab
code and makes slub code a bit faster (at least theoretically).

Also drop __GFP_NOWARN in the warning check.  This warning means a bug in
slab code itself, user-passed flags have nothing to do with it.

Nothing of this affects slob.

Link: http://lkml.kernel.org/r/20180927171502.226522-1-dvyukov@gmail.comSigned-off-by: NDmitry Vyukov <dvyukov@google.com>
Reported-by: syzbot+87829a10073277282ad1@syzkaller.appspotmail.com
Reported-by: syzbot+ef4e8fc3a06e9019bb40@syzkaller.appspotmail.com
Reported-by: syzbot+6e438f4036df52cbb863@syzkaller.appspotmail.com
Reported-by: syzbot+8574471d8734457d98aa@syzkaller.appspotmail.com
Reported-by: syzbot+af1504df0807a083dbd9@syzkaller.appspotmail.com
Acked-by: NChristoph Lameter <cl@linux.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Switch to bitmap_zalloc() to show clearly what we are allocating.  Besides
that it returns pointer of bitmap type instead of opaque void *.

Link: http://lkml.kernel.org/r/20180830104301.61649-1-andriy.shevchenko@linux.intel.comSigned-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NChristoph Lameter <cl@linux.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Tested-by: NDavid Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

What xtensa has in asm/vga.h is the same as what can be found in
asm-generic/vga.h.  So use the latter header.

Link: http://lkml.kernel.org/r/20180907132219.12979-1-jslaby@suse.czSigned-off-by: NJiri Slaby <jslaby@suse.cz>
Acked-by: NMax Filippov <jcmvbkbc@gmail.com>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change iomap_page_mkwrite() return type to vm_fault_t.

see commit 1c8f4220 ("mm: change return type to vm_fault_t") for
reference.

Link: http://lkml.kernel.org/r/20180827172050.GA18673@jordon-HP-15-Notebook-PCSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: NMatthew Wilcox <mawilcox@microsoft.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fixes gcc '-Wunused-but-set-variable' warning:

fs/ocfs2/refcounttree.c: In function 'ocfs2_create_reflink_node':
fs/ocfs2/refcounttree.c:4138:31: warning:
 variable 'rb' set but not used [-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/1536198443-113047-1-git-send-email-yuehaibing@huawei.comSigned-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The kernel module may sleep with holding a spinlock.

The function call paths (from bottom to top) in Linux-4.16 are:

[FUNC] get_zeroed_page(GFP_NOFS)
fs/ocfs2/dlm/dlmdebug.c, 332: get_zeroed_page in dlm_print_one_mle
fs/ocfs2/dlm/dlmmaster.c, 240: dlm_print_one_mle in __dlm_put_mle
fs/ocfs2/dlm/dlmmaster.c, 255: __dlm_put_mle in dlm_put_mle
fs/ocfs2/dlm/dlmmaster.c, 254: spin_lock in dlm_put_ml

[FUNC] get_zeroed_page(GFP_NOFS)
fs/ocfs2/dlm/dlmdebug.c, 332: get_zeroed_page in dlm_print_one_mle
fs/ocfs2/dlm/dlmmaster.c, 240: dlm_print_one_mle in __dlm_put_mle
fs/ocfs2/dlm/dlmmaster.c, 222: __dlm_put_mle in dlm_put_mle_inuse
fs/ocfs2/dlm/dlmmaster.c, 219: spin_lock in dlm_put_mle_inuse

To fix this bug, GFP_NOFS is replaced with GFP_ATOMIC.

This bug is found by my static analysis tool DSAC.

Link: http://lkml.kernel.org/r/20180901112528.27025-1-baijiaju1990@gmail.comSigned-off-by: NJia-Ju Bai <baijiaju1990@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Null check for kfree is unnecessary, so remove it.

Link: http://lkml.kernel.org/r/1535704514-26559-1-git-send-email-dingxiang@cmss.chinamobile.comSigned-off-by: NDing Xiang <dingxiang@cmss.chinamobile.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pointer 'eb' is being assigned but is never used hence it is
redundant and can be removed.

Cleans up clang warning:
warning: variable 'eb' set but not used [-Wunused-but-set-variable]

Link: http://lkml.kernel.org/r/20180828141907.10826-1-colin.king@canonical.comSigned-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Clang warns when more than one set of parentheses is used for a
single conditional statement:

fs/ocfs2/dlm/dlmthread.c:534:18: warning: equality comparison with extraneous
      parentheses [-Wparentheses-equality]
        if ((res->owner == dlm->node_num)) {
             ~~~~~~~~~~~^~~~~~~~~~~~~~~~
fs/ocfs2/dlm/dlmthread.c:534:18: note: remove extraneous parentheses around the
      comparison to silence this warning
        if ((res->owner == dlm->node_num)) {
            ~           ^               ~

Link: http://lkml.kernel.org/r/20180924181929.6853-1-natechancellor@gmail.comSigned-off-by: NNathan Chancellor <natechancellor@gmail.com>
Reported-by: NNick Desaulniers <ndesaulniers@google.com>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>