linux-toradex.git/Documentation/core-api, branch v5.16-rc6

Merge branch 'akpm' (patches from Andrew)

2021-11-06T21:08:17+00:00

Merge misc updates from Andrew Morton:
 "257 patches.

  Subsystems affected by this patch series: scripts, ocfs2, vfs, and
  mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache,
  gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc,
  pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools,
  memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm,
  vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram,
  cleanups, kfence, and damon)"

* emailed patches from Andrew Morton : (257 commits)
  mm/damon: remove return value from before_terminate callback
  mm/damon: fix a few spelling mistakes in comments and a pr_debug message
  mm/damon: simplify stop mechanism
  Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions
  Docs/admin-guide/mm/damon/start: simplify the content
  Docs/admin-guide/mm/damon/start: fix a wrong link
  Docs/admin-guide/mm/damon/start: fix wrong example commands
  mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
  mm/damon: remove unnecessary variable initialization
  Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM
  mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
  selftests/damon: support watermarks
  mm/damon/dbgfs: support watermarks
  mm/damon/schemes: activate schemes based on a watermarks mechanism
  tools/selftests/damon: update for regions prioritization of schemes
  mm/damon/dbgfs: support prioritization weights
  mm/damon/vaddr,paddr: support pageout prioritization
  mm/damon/schemes: prioritize regions within the quotas
  mm/damon/selftests: support schemes quotas
  mm/damon/dbgfs: support quotas of schemes
  ...

mm/memory_hotplug: remove HIGHMEM leftovers

2021-11-06T20:30:42+00:00

We don't support CONFIG_MEMORY_HOTPLUG on 32 bit and consequently not
HIGHMEM.  Let's remove any leftover code -- including the unused
"status_change_nid_high" field part of the memory notifier.

Link: https://lkml.kernel.org/r/20210929143600.49379-5-david@redhat.com
Signed-off-by: David Hildenbrand 
Reviewed-by: Oscar Salvador 
Cc: Alex Shi 
Cc: Andy Lutomirski 
Cc: Benjamin Herrenschmidt 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Greg Kroah-Hartman 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Jason Wang 
Cc: Jonathan Corbet 
Cc: Michael Ellerman 
Cc: "Michael S. Tsirkin" 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: "Rafael J. Wysocki" 
Cc: Shuah Khan 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

2021-11-02T22:26:41+00:00

Pull workqueue updates from Tejun Heo:
 "Nothing too interesting. An optimization to short-circuit noop cpumask
  updates, debug dump code reorg, and doc update"

* 'for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: doc: Call out the non-reentrance conditions
  workqueue: Introduce show_one_worker_pool and show_one_workqueue.
  workqueue: make sysfs of unbound kworker cpumask more clever

Merge tag 'printk-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

2021-11-02T17:53:45+00:00

Pull printk updates from Petr Mladek:

 - Extend %pGp print format to print hex value of the page flags

 - Use kvmalloc instead of kmalloc to allocate devkmsg buffers

 - Misc cleanup and warning fixes

* tag 'printk-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  vsprintf: Update %pGp documentation about that it prints hex value
  lib/vsprintf.c: Amend static asserts for format specifier flags
  vsprintf: Make %pGp print the hex value
  test_printf: Append strings more efficiently
  test_printf: Remove custom appending of '|'
  test_printf: Remove separate page_flags variable
  test_printf: Make pft array const
  ia64: don't do IA64_CMPXCHG_DEBUG without CONFIG_PRINTK
  printk: use gnu_printf format attribute for printk_sprint()
  printk: avoid -Wsometimes-uninitialized warning
  printk: use kvmalloc instead of kmalloc for devkmsg_user

Merge tag 'irq-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-11-01T20:09:10+00:00

Pull irq updates from Thomas Gleixner:
 "Updates for the interrupt subsystem:

  Core changes:

   - Prevent a potential deadlock when initial priority is assigned to a
     newly created interrupt thread. A recent change to plug a race
     between cpuset and __sched_setscheduler() introduced a new lock
     dependency which is now triggered. Break the lock dependency chain
     by moving the priority assignment to the thread function.

   - A couple of small updates to make the irq core RT safe.

   - Confine the irq_cpu_online/offline() API to the only left unfixable
     user Cavium Octeon so that it does not grow new usage.

   - A small documentation update

  Driver changes:

   - A large cross architecture rework to move irq_enter/exit() into the
     architecture code to make addressing the NOHZ_FULL/RCU issues
     simpler.

   - The obligatory new irq chip driver for Microchip EIC

   - Modularize a few irq chip drivers

   - Expand usage of devm_*() helpers throughout the driver code

   - The usual small fixes and improvements all over the place"

* tag 'irq-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  h8300: Fix linux/irqchip.h include mess
  dt-bindings: irqchip: renesas-irqc: Document r8a774e1 bindings
  MIPS: irq: Avoid an unused-variable error
  genirq: Hide irq_cpu_{on,off}line() behind a deprecated option
  irqchip/mips-gic: Get rid of the reliance on irq_cpu_online()
  MIPS: loongson64: Drop call to irq_cpu_offline()
  irq: remove handle_domain_{irq,nmi}()
  irq: remove CONFIG_HANDLE_DOMAIN_IRQ_IRQENTRY
  irq: riscv: perform irqentry in entry code
  irq: openrisc: perform irqentry in entry code
  irq: csky: perform irqentry in entry code
  irq: arm64: perform irqentry in entry code
  irq: arm: perform irqentry in entry code
  irq: add a (temporary) CONFIG_HANDLE_DOMAIN_IRQ_IRQENTRY
  irq: nds32: avoid CONFIG_HANDLE_DOMAIN_IRQ
  irq: arc: avoid CONFIG_HANDLE_DOMAIN_IRQ
  irq: add generic_handle_arch_irq()
  irq: unexport handle_irq_desc()
  irq: simplify handle_domain_{irq,nmi}()
  irq: mips: simplify do_domain_IRQ()
  ...

vsprintf: Update %pGp documentation about that it prints hex value

2021-11-01T14:55:06+00:00

The commit 23efd0804c0a869dfb1e7 ("vsprintf: Make %pGp print
the hex value") changed the behavior of %pGp printk format.
Update the documentation accordingly.

Fixes: 23efd0804c0a869dfb1e7 ("vsprintf: Make %pGp print the hex value")
Reviewed-by: Yafang Shao 
Signed-off-by: Petr Mladek 
Link: https://lore.kernel.org/r/YXlKqCPY9suM4mfT@alley

irq: remove handle_domain_{irq,nmi}()

2021-10-26T09:13:31+00:00

Now that entry code handles IRQ entry (including setting the IRQ regs)
before calling irqchip code, irqchip code can safely call
generic_handle_domain_irq(), and there's no functional reason for it to
call handle_domain_irq().

Let's cement this split of responsibility and remove handle_domain_irq()
entirely, updating irqchip drivers to call generic_handle_domain_irq().

For consistency, handle_domain_nmi() is similarly removed and replaced
with a generic_handle_domain_nmi() function which also does not perform
any entry logic.

Previously handle_domain_{irq,nmi}() had a WARN_ON() which would fire
when they were called in an inappropriate context. So that we can
identify similar issues going forward, similar WARN_ON_ONCE() logic is
added to the generic_handle_*() functions, and comments are updated for
clarity and consistency.

Signed-off-by: Mark Rutland 
Reviewed-by: Marc Zyngier 
Cc: Thomas Gleixner

workqueue: doc: Call out the non-reentrance conditions

2021-10-25T17:18:40+00:00

The current doc of workqueue API suggests that work items are
non-reentrant: any work item is guaranteed to be executed by at most one
worker system-wide at any given time. However this is not true, the
following case can cause a work item W executed by two workers at
the same time:

        queue_work_on(0, WQ1, W);
        // after a worker picks up W and clear the pending bit
        queue_work_on(1, WQ2, W);
        // workers on CPU0 and CPU1 will execute W in the same time.

, which means the non-reentrance of a work item is conditional, and
Lai Jiangshan provided a nice summary[1] of the conditions, therefore
use it to describe a work item instance and improve the doc.

[1]: https://lore.kernel.org/lkml/CAJhGHyDudet_xyNk=8xnuO2==o-u06s0E0GZVP4Q67nmQ84Ceg@mail.gmail.com/

Suggested-by: Matthew Wilcox 
Suggested-by: Tejun Heo 
Signed-off-by: Boqun Feng 
Signed-off-by: Tejun Heo

mm: Add flush_dcache_folio()

2021-10-18T11:49:36+00:00

This is a default implementation which calls flush_dcache_page() on
each page in the folio.  If architectures can do better, they should
implement their own version of it.

Signed-off-by: Matthew Wilcox (Oracle) 
Acked-by: Vlastimil Babka

mm/util: Add folio_mapping() and folio_file_mapping()

2021-09-27T13:27:30+00:00

These are the folio equivalent of page_mapping() and page_file_mapping().
Add an out-of-line page_mapping() wrapper around folio_mapping()
in order to prevent the page_folio() call from bloating every caller
of page_mapping().  Adjust page_file_mapping() and page_mapping_file()
to use folios internally.  Rename __page_file_mapping() to
swapcache_mapping() and change it to take a folio.

This ends up saving 122 bytes of text overall.  folio_mapping() is
45 bytes shorter than page_mapping() was, but the new page_mapping()
wrapper is 30 bytes.  The major reduction is a few bytes less in dozens
of nfs functions (which call page_file_mapping()).  Most of these appear
to be a slight change in gcc's register allocation decisions, which allow:

   48 8b 56 08         mov    0x8(%rsi),%rdx
   48 8d 42 ff         lea    -0x1(%rdx),%rax
   83 e2 01            and    $0x1,%edx
   48 0f 44 c6         cmove  %rsi,%rax

to become:

   48 8b 46 08         mov    0x8(%rsi),%rax
   48 8d 78 ff         lea    -0x1(%rax),%rdi
   a8 01               test   $0x1,%al
   48 0f 44 fe         cmove  %rsi,%rdi

for a reduction of a single byte.  Once the NFS client is converted to
use folios, this entire sequence will disappear.

Also add folio_mapping() documentation.

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Christoph Hellwig 
Acked-by: Jeff Layton 
Acked-by: Kirill A. Shutemov 
Acked-by: Vlastimil Babka 
Reviewed-by: William Kucharski 
Reviewed-by: David Howells