Convert the unbounded uses of sprintf to sysfs_emit.

A few conversions may now not end in a newline if the output buffer is
overflowed.

Link: https://lkml.kernel.org/r/0c90a90f466167f8c37de4b737553cf49c4a277f.1605376435.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the function to use sysfs_emit_at while neatening the uses of
sprintf and overwriting the last space char with a newline to avoid
possible output buffer overflow.

Miscellanea:

 - in shmem_enabled_show, the removal of the indirected use of fmt
   allows __printf verification

Link: https://lkml.kernel.org/r/b612a93825e5ea330cb68d2e8b516e9687a06cc6.1605376435.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The cocci script used in commit bdacbb8d04f ("mm: Use sysfs_emit for
struct kobject * uses") does not convert the name##_show macro because the
macro uses concatenation via ##.

Convert it by hand.

Link: https://lkml.kernel.org/r/45ec6cfc177d743f9c0ebaf35e43969dce43af42.1605376435.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert the only use of sprintf with struct kobject * that the cocci
script could not convert.

Miscellanea:

 - Neaten the uses of a constant string with sysfs_emit to use a const
   char * to reduce overall object size

Link: https://lkml.kernel.org/r/7df6be66bbd68e1a0bca9d35aca1341dbf94d2a7.1605376435.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm: Convert sysfs sprintf family to sysfs_emit", v2.

Use the new sysfs_emit family and not the sprintf family.

This patch (of 5):

Use the sysfs_emit function instead of the sprintf family.

Done with cocci script as in commit 3c6bff3c ("RDMA: Convert sysfs
kobject * show functions to use sysfs_emit()")

Link: https://lkml.kernel.org/r/cover.1605376435.git.joe@perches.com
Link: https://lkml.kernel.org/r/9c249215bad6df616ba0410ad980042694970c1b.1605376435.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
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>

Kernel-doc markups should use this format:
        identifier - description

Fix some issues on mm files:

1) The definition for get_user_pages_locked() doesn't follow it.  Also,
   it expects a short descrpition at the header, followed by a long one,
   after the parameters.  Fix it.

2) Kernel-doc requires that a kernel-doc markup to be immediately below
   the function prototype, as otherwise it will rename it.  So, move
   get_pfnblock_flags_mask() description to the right place.

3) Make invalidate_mapping_pagevec() to also follow the expected
   kernel-doc format.

While here, fix a few minor English syntax issues, as suggested
by Matthew:
	will used -> will be used
	similar with -> similar to

Link: https://lkml.kernel.org/r/80e85dddc92d333bc2159ee8a2294921612e8745.1605521731.git.mchehab+huawei@kernel.orgSigned-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Suggested-by: Mattew Wilcox <willy@infradead.org>	[English fixes]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The pointer iov_r is being initialized with a value that is never read and
it is being updated later with a new value.  The initialization is
redundant and can be removed.

Link: https://lkml.kernel.org/r/20201102120614.694917-1-colin.king@canonical.comSigned-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rework the list_add code to make it more readable and simple.

Link: https://lkml.kernel.org/r/20201015130107.65195-1-linmiaohe@huawei.comSigned-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Right now, all new ZIP drivers are adapted to crypto_acomp APIs rather
than legacy crypto_comp APIs.  Tradiontal ZIP drivers like lz4,lzo etc
have been also wrapped into acomp via scomp backend.  But zswap.c is still
using the old APIs.  That means zswap won't be able to work on any new ZIP
drivers in kernel.

This patch moves to use cryto_acomp APIs to fix the disconnected bridge
between new ZIP drivers and zswap.  It is probably the first real user to
use acomp but perhaps not a good example to demonstrate how multiple acomp
requests can be executed in parallel in one acomp instance.  frontswap is
doing page load and store page by page synchronously.  swap_writepage()
depends on the completion of frontswap_store() to decide if it should call
__swap_writepage() to swap to disk.

However this patch creates multiple acomp instances, so multiple threads
running on multiple different cpus can actually do (de)compression
parallelly, leveraging the power of multiple ZIP hardware queues.  This is
also consistent with frontswap's page management model.

The old zswap code uses atomic context and avoids the race conditions
while shared resources like zswap_dstmem are accessed.  Here since acomp
can sleep, per-cpu mutex is used to replace preemption-disable.

While it is possible to make mm/page_io.c and mm/frontswap.c support async
(de)compression in some way, the entire design requires careful thinking
and performance evaluation.  For the first step, the base with fixed
connection between ZIP drivers and zswap should be built.

Link: https://lkml.kernel.org/r/20201107065332.26992-1-song.bao.hua@hisilicon.comSigned-off-by: NBarry Song <song.bao.hua@hisilicon.com>
Acked-by: NVitaly Wool <vitalywool@gmail.com>
Cc: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Mahipal Challa <mahipalreddy2006@gmail.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Zhou Wang <wangzhou1@hisilicon.com>
Cc: Colin Ian King <colin.king@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix smatch warning:

  mm/zswap.c:425 zswap_cpu_comp_prepare() warn: passing zero to 'PTR_ERR'

crypto_alloc_comp() never return NULL, use IS_ERR instead of
IS_ERR_OR_NULL to fix this.

Link: https://lkml.kernel.org/r/20201031055615.28080-1-yuehaibing@huawei.com
Fixes: f1c54846 ("zswap: dynamic pool creation")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These should be const, so make it so.

Link: https://lkml.kernel.org/r/1791535ee0b00f4a5c68cc4a8adada06593ad8f1.1601770305.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

CONFIG_PAGE_POISONING_ZERO uses the zero pattern instead of 0xAA.  It was
introduced by commit 1414c7f4 ("mm/page_poisoning.c: allow for zero
poisoning"), noting that using zeroes retains the benefit of sanitizing
content of freed pages, with the benefit of not having to zero them again
on alloc, and the downside of making some forms of corruption (stray
writes of NULLs) harder to detect than with the 0xAA pattern.  Together
with CONFIG_PAGE_POISONING_NO_SANITY it made possible to sanitize the
contents on free without checking it back on alloc.

These days we have the init_on_free() option to achieve sanitization with
zeroes and to save clearing on alloc (and without checking on alloc).
Arguably if someone does choose to check the poison for corruption on
alloc, the savings of not clearing the page are secondary, and it makes
sense to always use the 0xAA poison pattern.  Thus, remove the
CONFIG_PAGE_POISONING_ZERO option for being redundant.

Link: https://lkml.kernel.org/r/20201113104033.22907-6-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

CONFIG_PAGE_POISONING_NO_SANITY skips the check on page alloc whether the
poison pattern was corrupted, suggesting a use-after-free.  The motivation
to introduce it in commit 8823b1db ("mm/page_poison.c: enable
PAGE_POISONING as a separate option") was to simply sanitize freed pages,
optimally together with CONFIG_PAGE_POISONING_ZERO.

These days we have an init_on_free=1 boot option, which makes this use
case of page poisoning redundant.  For sanitizing, writing zeroes is
sufficient, there is pretty much no benefit from writing the 0xAA poison
pattern to freed pages, without checking it back on alloc.  Thus, remove
this option and suggest init_on_free instead in the main config's help.

Link: https://lkml.kernel.org/r/20201113104033.22907-5-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Page poisoning used to be incompatible with hibernation, as the state of
poisoned pages was lost after resume, thus enabling CONFIG_HIBERNATION
forces CONFIG_PAGE_POISONING_NO_SANITY.  For the same reason, the
poisoning with zeroes variant CONFIG_PAGE_POISONING_ZERO used to disable
hibernation.  The latter restriction was removed by commit 1ad1410f
("PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO") and
similarly for init_on_free by commit 18451f9f ("PM: hibernate: fix
crashes with init_on_free=1") by making sure free pages are cleared after
resume.

We can use the same mechanism to instead poison free pages with
PAGE_POISON after resume.  This covers both zero and 0xAA patterns.  Thus
we can remove the Kconfig restriction that disables page poison sanity
checking when hibernation is enabled.

Link: https://lkml.kernel.org/r/20201113104033.22907-4-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>	[hibernation]
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 11c9c7ed ("mm/page_poison.c: replace bool variable with static
key") changed page_poisoning_enabled() to a static key check.  However,
the function is not inlined, so each check still involves a function call
with overhead not eliminated when page poisoning is disabled.

Analogically to how debug_pagealloc is handled, this patch converts
page_poisoning_enabled() back to boolean check, and introduces
page_poisoning_enabled_static() for fast paths.  Both functions are
inlined.

The function kernel_poison_pages() is also called unconditionally and does
the static key check inside.  Remove it from there and put it to callers.
Also split it to two functions kernel_poison_pages() and
kernel_unpoison_pages() instead of the confusing bool parameter.

Also optimize the check that enables page poisoning instead of
debug_pagealloc for architectures without proper debug_pagealloc support.
Move the check to init_mem_debugging_and_hardening() to enable a single
static key instead of having two static branches in
page_poisoning_enabled_static().

Link: https://lkml.kernel.org/r/20201113104033.22907-3-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
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 "cleanup page poisoning", v3.

I have identified a number of issues and opportunities for cleanup with
CONFIG_PAGE_POISON and friends:

 - interaction with init_on_alloc and init_on_free parameters depends on
   the order of parameters (Patch 1)

 - the boot time enabling uses static key, but inefficienty (Patch 2)

 - sanity checking is incompatible with hibernation (Patch 3)

 - CONFIG_PAGE_POISONING_NO_SANITY can be removed now that we have
   init_on_free (Patch 4)

 - CONFIG_PAGE_POISONING_ZERO can be most likely removed now that we
   have init_on_free (Patch 5)

This patch (of 5):

Enabling page_poison=1 together with init_on_alloc=1 or init_on_free=1
produces a warning in dmesg that page_poison takes precedence.  However,
as these warnings are printed in early_param handlers for
init_on_alloc/free, they are not printed if page_poison is enabled later
on the command line (handlers are called in the order of their
parameters), or when init_on_alloc/free is always enabled by the
respective config option - before the page_poison early param handler is
called, it is not considered to be enabled.  This is inconsistent.

We can remove the dependency on order by making the init_on_* parameters
only set a boolean variable, and postponing the evaluation after all early
params have been processed.  Introduce a new
init_mem_debugging_and_hardening() function for that, and move the related
debug_pagealloc processing there as well.

As a result init_mem_debugging_and_hardening() knows always accurately if
init_on_* and/or page_poison options were enabled.  Thus we can also
optimize want_init_on_alloc() and want_init_on_free().  We don't need to
check page_poisoning_enabled() there, we can instead not enable the
init_on_* static keys at all, if page poisoning is enabled.  This results
in a simpler and more effective code.

Link: https://lkml.kernel.org/r/20201113104033.22907-1-vbabka@suse.cz
Link: https://lkml.kernel.org/r/20201113104033.22907-2-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NMike Rapoport <rppt@linux.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Laura Abbott <labbott@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It is required to print 'count' of pages, along with the pages, passed to
cma_release to debug the cases of mismatched count value passed between
cma_alloc() and cma_release() from a code path.

As an example, consider the below scenario:

1) CMA pool size is 4MB and

2) User doing the erroneous step of allocating 2 pages but freeing 1
   page in a loop from this CMA pool.  The step 2 causes cma_alloc() to
   return NULL at one point of time because of -ENOMEM condition.

And the current pr_debug logs is not giving the info about these types of
allocation patterns because of count value not being printed in
cma_release().

We are printing the count value in the trace logs, just extend the same to
pr_debug logs too.

[akpm@linux-foundation.org: fix printk warning]

Link: https://lkml.kernel.org/r/1606318341-29521-1-git-send-email-charante@codeaurora.orgSigned-off-by: NCharan Teja Reddy <charante@codeaurora.org>
Reviewed-by: NSouptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Vinayak Menon <vinmenon@codeaurora.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>

The cma_mutex which protects alloc_contig_range() was first appeared in
commit 7ee793a6 ("cma: Remove potential deadlock situation"), at that
time, there is no guarantee the behavior of concurrency inside
alloc_contig_range().

After commit 2c7452a0 ("mm/page_isolation.c: make
start_isolate_page_range() fail if already isolated")

  > However, two subsystems (CMA and gigantic
  > huge pages for example) could attempt operations on the same range.  If
  > this happens, one thread may 'undo' the work another thread is doing.
  > This can result in pageblocks being incorrectly left marked as
  > MIGRATE_ISOLATE and therefore not available for page allocation.

The concurrency inside alloc_contig_range() was clarified.

Now we can find that hugepage and virtio call alloc_contig_range() without
any lock, thus cma_mutex is "redundant" in cma_alloc() now.

Link: https://lkml.kernel.org/r/20201020102241.3729-1-lecopzer.chen@mediatek.comSigned-off-by: NLecopzer Chen <lecopzer.chen@mediatek.com>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: YJ Chiang <yj.chiang@mediatek.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

"dst" parameter to migrate_vma_insert_page() is not used anymore.

Link: https://lkml.kernel.org/r/CANubcdUwCAMuUyamG2dkWP=cqSR9MAS=tHLDc95kQkqU-rEnAg@mail.gmail.comSigned-off-by: NStephen Zhang <starzhangzsd@gmail.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In the current implementation unmap_and_move() would return -ENOMEM if THP
migration is unsupported, then the THP will be split.  If split is failed
just exit without trying to migrate other pages.  It doesn't make too much
sense since there may be enough free memory to migrate other pages and
there may be a lot base pages on the list.

Return -ENOSYS to make consistent with hugetlb.  And if THP split is
failed just skip and try other pages on the list.

Just skip the whole list and exit when free memory is really low.

Link: https://lkml.kernel.org/r/20201113205359.556831-6-shy828301@gmail.comSigned-off-by: NYang Shi <shy828301@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The migrate_prep{_local} never fails, so it is pointless to have return
value and check the return value.

Link: https://lkml.kernel.org/r/20201113205359.556831-5-shy828301@gmail.comSigned-off-by: NYang Shi <shy828301@gmail.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The NUMA balancing skip shared exec base page.  Since
CONFIG_READ_ONLY_THP_FOR_FS was introduced, there are probably shared exec
THP, so skip such THPs for NUMA balancing as well.

And Willy's regular filesystem THP support patches could create shared
exec THP wven without that config.

In addition, the page_is_file_lru() is used to tell if the page is file
cache or not, but it filters out shmem page.  It sounds like a typical
usecase by putting executables in shmem to achieve performance gain via
using shmem-THP, so it sounds worth skipping migration for such case too.

Link: https://lkml.kernel.org/r/20201113205359.556831-4-shy828301@gmail.comSigned-off-by: NYang Shi <shy828301@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When unmap_and_move{_huge_page}() returns !-EAGAIN and
!MIGRATEPAGE_SUCCESS, the page would be put back to LRU or proper list if
it is non-LRU movable page.  But, the callers always call
putback_movable_pages() to put the failed pages back later on, so it seems
not very efficient to put every single page back immediately, and the code
looks convoluted.

Put the failed page on a separate list, then splice the list to migrate
list when all pages are tried.  It is the caller's responsibility to call
putback_movable_pages() to handle failures.  This also makes the code
simpler and more readable.

After the change the rules are:
    * Success: non hugetlb page will be freed, hugetlb page will be put
               back
    * -EAGAIN: stay on the from list
    * -ENOMEM: stay on the from list
    * Other errno: put on ret_pages list then splice to from list

The from list would be empty iff all pages are migrated successfully, it
was not so before.  This has no impact to current existing callsites.

Link: https://lkml.kernel.org/r/20201113205359.556831-3-shy828301@gmail.comSigned-off-by: NYang Shi <shy828301@gmail.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm: misc migrate cleanup and improvement", v3.

This patch (of 5):

The commit 9f4e41f4 ("mm: refactor truncate_complete_page()")
refactored truncate_complete_page(), and it is not existed anymore,
correct the comment in vmscan and migrate to avoid confusion.

Link: https://lkml.kernel.org/r/20201113205359.556831-1-shy828301@gmail.com
Link: https://lkml.kernel.org/r/20201113205359.556831-2-shy828301@gmail.comSigned-off-by: NYang Shi <shy828301@gmail.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We can only kmap() one subpage of a THP at a time, so loop over all
relevant subpages, skipping ones which don't need to be zeroed.  This is
too large to inline when THPs are enabled and we actually need highmem, so
put it in highmem.c.

[willy@infradead.org: start1 was allowed to be less than start2]

Link: https://lkml.kernel.org/r/20201124041507.28996-1-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When migrating a zero page or pte_none() anonymous page to device private
memory, migrate_vma_setup() will initialize the src[] array with a NULL
PFN.  This lets the device driver allocate device private memory and clear
it instead of DMAing a page of zeros over the device bus.

Since the source page didn't exist at the time, no struct page was locked
nor a migration PTE inserted into the CPU page tables.  The actual PTE
insertion happens in migrate_vma_pages() when it tries to insert the
device private struct page PTE into the CPU page tables.
migrate_vma_pages() has to call the mmu notifiers again since another
device could fault on the same page before the page table locks are
acquired.

Allow device drivers to optimize the invalidation similar to
migrate_vma_setup() by calling mmu_notifier_range_init() which sets struct
mmu_notifier_range event type to MMU_NOTIFY_MIGRATE and the
migrate_pgmap_owner field.

Link: https://lkml.kernel.org/r/20201021191335.10916-1-rcampbell@nvidia.comSigned-off-by: NRalph Campbell <rcampbell@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The word in the comment is misspelled, it should be "include".

Link: https://lkml.kernel.org/r/20201024114144.GA20552@lilongSigned-off-by: NLong Li <lonuxli.64@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change the comment of is_dump_unreclaim_slabs(), it just check whether
nr_unreclaimable slabs amount is greater than user memory, and explain why
we dump unreclaim slabs.

Rename it to should_dump_unreclaim_slab() maybe better.

Link: https://lkml.kernel.org/r/20201030182704.GA53949@rlkSigned-off-by: Hui Su <sh_def@163.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

defer_compaction() and compaction_deferred() and compaction_restarting()
in mm/compaction.c won't be used in other files, so make them static, and
remove the declaration in the header file.

Take the chance to fix a typo.

Link: https://lkml.kernel.org/r/20201123170801.GA9625@rlkSigned-off-by: Hui Su <sh_def@163.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Nitin Gupta <nigupta@nvidia.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Mateusz Nosek <mateusznosek0@gmail.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>

Since commit 837d026d ("mm/compaction: more trace to understand
when/why compaction start/finish"), the comment place is not suitable.

So move compaction_suitable's comment to right place.

Link: https://lkml.kernel.org/r/20201116144121.GA385717@rlkSigned-off-by: Hui Su <sh_def@163.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are two 'start_pfn' declared in compact_zone() which have different
meanings.  Rename the second one to 'iteration_start_pfn' to prevent
confusion.

Also, remove an useless semicolon.

Link: https://lkml.kernel.org/r/20201019115044.1571-1-yanfei.xu@windriver.comSigned-off-by: NYanfei Xu <yanfei.xu@windriver.com>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NPankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace get_cpu_ptr() with migrate_disable()+this_cpu_ptr() so RT can take
spinlocks that become sleeping locks.

Signed-off-by Mike Galbraith <efault@gmx.de>

Link: https://lkml.kernel.org/r/20201209145151.18994-3-vitaly.wool@konsulko.comSigned-off-by: NVitaly Wool <vitaly.wool@konsulko.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use temporary slots in reclaim function to avoid possible race when
freeing those.

While at it, make sure we check CLAIMED flag under page lock in the
reclaim function to make sure we are not racing with z3fold_alloc().

Link: https://lkml.kernel.org/r/20201209145151.18994-4-vitaly.wool@konsulko.comSigned-off-by: NVitaly Wool <vitaly.wool@konsulko.com>
Cc: <stable@vger.kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "z3fold: stability / rt fixes".

Address z3fold stability issues under stress load, primarily in the
reclaim and free aspects.  Besides, it fixes the locking problems that
were only seen in real-time kernel configuration.

This patch (of 3):

There used to be two places in the code where slots could be freed, namely
when freeing the last allocated handle from the slots and when releasing
the z3fold header these slots aree linked to.  The logic to decide on
whether to free certain slots was complicated and error prone in both
functions and it led to failures in RT case.

To fix that, make free_handle() the single point of freeing slots.

Link: https://lkml.kernel.org/r/20201209145151.18994-1-vitaly.wool@konsulko.com
Link: https://lkml.kernel.org/r/20201209145151.18994-2-vitaly.wool@konsulko.comSigned-off-by: NVitaly Wool <vitaly.wool@konsulko.com>
Tested-by: NMike Galbraith <efault@gmx.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A max order page has no buddy page and never merges to another order.  So
isolating and then freeing it is pointless.

Link: https://lkml.kernel.org/r/20201202122114.75316-1-songmuchun@bytedance.com
Fixes: 3c605096 ("mm/page_alloc: restrict max order of merging on isolated pageblock")
Signed-off-by: NMuchun Song <songmuchun@bytedance.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.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>

No point in having the filename inside the file.

Link: https://lkml.kernel.org/r/20201115141541.3878-1-hymmsx.yu@gmail.comSigned-off-by: Nlogic.yu <hymmsx.yu@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The refactoring to kswapd() in commit e716f2eb ("mm, vmscan: prevent
kswapd sleeping prematurely due to mismatched classzone_idx") turned an
assignment to reclaim_order into a dead store, as in all further paths,
reclaim_order will be assigned again before it is used.

make clang-analyzer on x86_64 tinyconfig caught my attention with:

  mm/vmscan.c: warning: Although the value stored to 'reclaim_order' is used in the enclosing expression, the value is never actually read from 'reclaim_order' [clang-analyzer-deadcode.DeadStores]

Compilers will detect this unneeded assignment and optimize this anyway.
So, the resulting binary is identical before and after this change.

Simplify the code and remove unneeded assignment to make clang-analyzer
happy.

No functional change. No change in binary code.

Link: https://lkml.kernel.org/r/20201004125827.17679-1-lukas.bulwahn@gmail.comSigned-off-by: NLukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On 2-node NUMA hosts we see bursts of kswapd reclaim and subsequent
pressure spikes and stalls from cache refaults while there is plenty of
free memory in the system.

Usually, kswapd is woken up when all eligible nodes in an allocation are
full.  But the code related to watermark boosting can wake kswapd on one
full node while the other one is mostly empty.  This may be justified to
fight fragmentation, but is currently unconditionally done whether
watermark boosting is occurring or not.

In our case, many of our workloads' throughput scales with available
memory, and pure utilization is a more tangible concern than trends
around longer-term fragmentation.  As a result we generally disable
watermark boosting.

Wake kswapd only woken when watermark boosting is requested.

Link: https://lkml.kernel.org/r/20201020175833.397286-1-hannes@cmpxchg.org
Fixes: 1c30844d ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Preserve the error code from region_add() instead of returning success.

Link: https://lkml.kernel.org/r/X9NGZWnZl5/Mt99R@mwanda
Fixes: 0db9d74e ("hugetlb: disable region_add file_region coalescing")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NMike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: Mina Almasry <almasrymina@google.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>

hugetlb_add_hstate initializes nr_huge_pages and free_huge_pages to 0, but
since hstates[] is a global variable, all its fields are defined to 0
already.

Link: https://lkml.kernel.org/r/20201119112141.6452-1-osalvador@suse.deSigned-off-by: NOscar Salvador <osalvador@suse.de>
Reviewed-by: NMike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>