Commit 65090f30 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'akpm' (patches from Andrew) 

Merge misc updates from Andrew Morton:
 "191 patches.

  Subsystems affected by this patch series: kthread, ia64, scripts,
  ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab,
  slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap,
  mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization,
  pagealloc, and memory-failure)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits)
  mm,hwpoison: make get_hwpoison_page() call get_any_page()
  mm,hwpoison: send SIGBUS with error virutal address
  mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes
  mm/page_alloc: allow high-order pages to be stored on the per-cpu lists
  mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM
  mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
  docs: remove description of DISCONTIGMEM
  arch, mm: remove stale mentions of DISCONIGMEM
  mm: remove CONFIG_DISCONTIGMEM
  m68k: remove support for DISCONTIGMEM
  arc: remove support for DISCONTIGMEM
  arc: update comment about HIGHMEM implementation
  alpha: remove DISCONTIGMEM and NUMA
  mm/page_alloc: move free_the_page
  mm/page_alloc: fix counting of managed_pages
  mm/page_alloc: improve memmap_pages dbg msg
  mm: drop SECTION_SHIFT in code comments
  mm/page_alloc: introduce vm.percpu_pagelist_high_fraction
  mm/page_alloc: limit the number of pages on PCP lists when reclaim is active
  mm/page_alloc: scale the number of pages that are batch freed
  ...
parents 349a2d52 0ed950d1

Documentation/admin-guide/kernel-parameters.txt

+6 −0
Original line number Diff line number Diff line
@@ -3591,6 +3591,12 @@ 
			off: turn off poisoning (default)

			on: turn on poisoning



	page_reporting.page_reporting_order=

			[KNL] Minimal page reporting order

			Format: <integer>

			Adjust the minimal page reporting order. The page

			reporting is disabled when it exceeds (MAX_ORDER-1).



	panic=		[KNL] Kernel behaviour on panic: delay <timeout>

			timeout > 0: seconds before rebooting

			timeout = 0: wait forever

Documentation/admin-guide/lockup-watchdogs.rst

+2 −2
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ in principle, they should work in any architecture where these 
subsystems are present.



A periodic hrtimer runs to generate interrupts and kick the watchdog

task. An NMI perf event is generated every "watchdog_thresh"

job. An NMI perf event is generated every "watchdog_thresh"

(compile-time initialized to 10 and configurable through sysctl of the

same name) seconds to check for hardlockups. If any CPU in the system

does not receive any hrtimer interrupt during that time the
@@ -47,7 +47,7 @@ does not receive any hrtimer interrupt during that time the 
generate a kernel warning or call panic, depending on the

configuration.



The watchdog task is a high priority kernel thread that updates a

The watchdog job runs in a stop scheduling thread that updates a

timestamp every time it is scheduled. If that timestamp is not updated

for 2*watchdog_thresh seconds (the softlockup threshold) the

'softlockup detector' (coded inside the hrtimer callback function)

Documentation/admin-guide/sysctl/kernel.rst

+5 −5
Original line number Diff line number Diff line
@@ -1297,11 +1297,11 @@ This parameter can be used to control the soft lockup detector. 
= =================================



The soft lockup detector monitors CPUs for threads that are hogging the CPUs

without rescheduling voluntarily, and thus prevent the 'watchdog/N' threads

from running. The mechanism depends on the CPUs ability to respond to timer

interrupts which are needed for the 'watchdog/N' threads to be woken up by

the watchdog timer function, otherwise the NMI watchdog — if enabled — can

detect a hard lockup condition.

without rescheduling voluntarily, and thus prevent the 'migration/N' threads

from running, causing the watchdog work fail to execute. The mechanism depends

on the CPUs ability to respond to timer interrupts which are needed for the

watchdog work to be queued by the watchdog timer function, otherwise the NMI

watchdog — if enabled — can detect a hard lockup condition.





stack_erasing

Documentation/admin-guide/sysctl/vm.rst

+22 −20
Original line number Diff line number Diff line
@@ -64,7 +64,7 @@ Currently, these files are in /proc/sys/vm: 
- overcommit_ratio

- page-cluster

- panic_on_oom

- percpu_pagelist_fraction

- percpu_pagelist_high_fraction

- stat_interval

- stat_refresh

- numa_stat
@@ -790,22 +790,24 @@ panic_on_oom=2+kdump gives you very strong tool to investigate 
why oom happens. You can get snapshot.





percpu_pagelist_fraction

========================

percpu_pagelist_high_fraction

=============================



This is the fraction of pages at most (high mark pcp->high) in each zone that

are allocated for each per cpu page list.  The min value for this is 8.  It

means that we don't allow more than 1/8th of pages in each zone to be

allocated in any single per_cpu_pagelist.  This entry only changes the value

of hot per cpu pagelists.  User can specify a number like 100 to allocate

1/100th of each zone to each per cpu page list.

This is the fraction of pages in each zone that are can be stored to

per-cpu page lists. It is an upper boundary that is divided depending

on the number of online CPUs. The min value for this is 8 which means

that we do not allow more than 1/8th of pages in each zone to be stored

on per-cpu page lists. This entry only changes the value of hot per-cpu

page lists. A user can specify a number like 100 to allocate 1/100th of

each zone between per-cpu lists.



The batch value of each per cpu pagelist is also updated as a result.  It is

set to pcp->high/4.  The upper limit of batch is (PAGE_SHIFT * 8)

The batch value of each per-cpu page list remains the same regardless of

the value of the high fraction so allocation latencies are unaffected.



The initial value is zero.  Kernel does not use this value at boot time to set

the high water marks for each per cpu page list.  If the user writes '0' to this

sysctl, it will revert to this default behavior.

The initial value is zero. Kernel uses this value to set the high pcp->high

mark based on the low watermark for the zone and the number of local

online CPUs.  If the user writes '0' to this sysctl, it will revert to

this default behavior.





stat_interval
@@ -936,12 +938,12 @@ allocations, THP and hugetlbfs pages. 


To make it sensible with respect to the watermark_scale_factor

parameter, the unit is in fractions of 10,000. The default value of

15,000 on !DISCONTIGMEM configurations means that up to 150% of the high

watermark will be reclaimed in the event of a pageblock being mixed due

to fragmentation. The level of reclaim is determined by the number of

fragmentation events that occurred in the recent past. If this value is

smaller than a pageblock then a pageblocks worth of pages will be reclaimed

(e.g.  2MB on 64-bit x86). A boost factor of 0 will disable the feature.

15,000 means that up to 150% of the high watermark will be reclaimed in the

event of a pageblock being mixed due to fragmentation. The level of reclaim

is determined by the number of fragmentation events that occurred in the

recent past. If this value is smaller than a pageblock then a pageblocks

worth of pages will be reclaimed (e.g.  2MB on 64-bit x86). A boost factor

of 0 will disable the feature.





watermark_scale_factor

Documentation/dev-tools/kasan.rst

+4 −5
Original line number Diff line number Diff line
@@ -447,11 +447,10 @@ When a test fails due to a failed ``kmalloc``:: 


When a test fails due to a missing KASAN report::



        # kmalloc_double_kzfree: EXPECTATION FAILED at lib/test_kasan.c:629

        Expected kasan_data->report_expected == kasan_data->report_found, but

        kasan_data->report_expected == 1

        kasan_data->report_found == 0

        not ok 28 - kmalloc_double_kzfree

        # kmalloc_double_kzfree: EXPECTATION FAILED at lib/test_kasan.c:974

        KASAN failure expected in "kfree_sensitive(ptr)", but none occurred

        not ok 44 - kmalloc_double_kzfree





At the end the cumulative status of all KASAN tests is printed. On success::