linux.git/mm/memory_hotplug.c, branch v5.9-rc4

mm: replace hpage_nr_pages with thp_nr_pages

2020-08-15T02:56:56+00:00

The thp prefix is more frequently used than hpage and we should be
consistent between the various functions.

[akpm@linux-foundation.org: fix mm/migrate.c]

Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Andrew Morton 
Reviewed-by: William Kucharski 
Reviewed-by: Zi Yan 
Cc: Mike Kravetz 
Cc: David Hildenbrand 
Cc: "Kirill A. Shutemov" 
Link: http://lkml.kernel.org/r/20200629151959.15779-6-willy@infradead.org
Signed-off-by: Linus Torvalds

mm/migrate: introduce a standard migration target allocation function

2020-08-12T17:58:02+00:00

There are some similar functions for migration target allocation.  Since
there is no fundamental difference, it's better to keep just one rather
than keeping all variants.  This patch implements base migration target
allocation function.  In the following patches, variants will be converted
to use this function.

Changes should be mechanical, but, unfortunately, there are some
differences.  First, some callers' nodemask is assgined to NULL since NULL
nodemask will be considered as all available nodes, that is,
&node_states[N_MEMORY].  Second, for hugetlb page allocation, gfp_mask is
redefined as regular hugetlb allocation gfp_mask plus __GFP_THISNODE if
user provided gfp_mask has it.  This is because future caller of this
function requires to set this node constaint.  Lastly, if provided nodeid
is NUMA_NO_NODE, nodeid is set up to the node where migration source
lives.  It helps to remove simple wrappers for setting up the nodeid.

Note that PageHighmem() call in previous function is changed to open-code
"is_highmem_idx()" since it provides more readability.

[akpm@linux-foundation.org: tweak patch title, per Vlastimil]
[akpm@linux-foundation.org: fix typo in comment]

Signed-off-by: Joonsoo Kim 
Signed-off-by: Andrew Morton 
Acked-by: Vlastimil Babka 
Acked-by: Michal Hocko 
Cc: Christoph Hellwig 
Cc: Mike Kravetz 
Cc: Naoya Horiguchi 
Cc: Roman Gushchin 
Link: http://lkml.kernel.org/r/1594622517-20681-6-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Linus Torvalds

mm, memory_hotplug: update pcp lists everytime onlining a memory block

2020-08-12T17:57:57+00:00

When onlining a first memory block in a zone, pcp lists are not updated
thus pcp struct will have the default setting of ->high = 0,->batch = 1.

This means till the second memory block in a zone(if it have) is onlined
the pcp lists of this zone will not contain any pages because pcp's
->count is always greater than ->high thus free_pcppages_bulk() is called
to free batch size(=1) pages every time system wants to add a page to the
pcp list through free_unref_page().

To put this in a word, system is not using benefits offered by the pcp
lists when there is a single onlineable memory block in a zone.  Correct
this by always updating the pcp lists when memory block is onlined.

Fixes: 1f522509c77a ("mem-hotplug: avoid multiple zones sharing same boot strapping boot_pageset")
Signed-off-by: Charan Teja Reddy 
Signed-off-by: Andrew Morton 
Reviewed-by: David Hildenbrand 
Acked-by: Vlastimil Babka 
Acked-by: Michal Hocko 
Cc: Vinayak Menon 
Link: http://lkml.kernel.org/r/1596372896-15336-1-git-send-email-charante@codeaurora.org
Signed-off-by: Linus Torvalds

mm/memory_hotplug: fix unpaired mem_hotplug_begin/done

2020-08-12T17:57:57+00:00

When check_memblock_offlined_cb() returns failed rc(e.g. the memblock is
online at that time), mem_hotplug_begin/done is unpaired in such case.

Therefore a warning:
 Call Trace:
  percpu_up_write+0x33/0x40
  try_remove_memory+0x66/0x120
  ? _cond_resched+0x19/0x30
  remove_memory+0x2b/0x40
  dev_dax_kmem_remove+0x36/0x72 [kmem]
  device_release_driver_internal+0xf0/0x1c0
  device_release_driver+0x12/0x20
  bus_remove_device+0xe1/0x150
  device_del+0x17b/0x3e0
  unregister_dev_dax+0x29/0x60
  devm_action_release+0x15/0x20
  release_nodes+0x19a/0x1e0
  devres_release_all+0x3f/0x50
  device_release_driver_internal+0x100/0x1c0
  driver_detach+0x4c/0x8f
  bus_remove_driver+0x5c/0xd0
  driver_unregister+0x31/0x50
  dax_pmem_exit+0x10/0xfe0 [dax_pmem]

Fixes: f1037ec0cc8a ("mm/memory_hotplug: fix remove_memory() lockdep splat")
Signed-off-by: Jia He 
Signed-off-by: Andrew Morton 
Reviewed-by: David Hildenbrand 
Acked-by: Michal Hocko 
Acked-by: Dan Williams 
Cc: 	[5.6+]
Cc: Andy Lutomirski 
Cc: Baoquan He 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: Chuhong Yuan 
Cc: Dave Hansen 
Cc: Dave Jiang 
Cc: Fenghua Yu 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Jonathan Cameron 
Cc: Kaly Xin 
Cc: Logan Gunthorpe 
Cc: Masahiro Yamada 
Cc: Mike Rapoport 
Cc: Peter Zijlstra 
Cc: Rich Felker 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vishal Verma 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Link: http://lkml.kernel.org/r/20200710031619.18762-3-justin.he@arm.com
Signed-off-by: Linus Torvalds

mm/memory_hotplug: introduce default dummy memory_add_physaddr_to_nid()

2020-08-12T17:57:57+00:00

This is to introduce a general dummy helper.  memory_add_physaddr_to_nid()
is a fallback option to get the nid in case NUMA_NO_NID is detected.

After this patch, arm64/sh/s390 can simply use the general dummy version.
PowerPC/x86/ia64 will still use their specific version.

This is the preparation to set a fallback value for dev_dax->target_node.

Signed-off-by: Jia He 
Signed-off-by: Andrew Morton 
Reviewed-by: David Hildenbrand 
Cc: Dan Williams 
Cc: Michal Hocko 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Tony Luck 
Cc: Fenghua Yu 
Cc: Yoshinori Sato 
Cc: Rich Felker 
Cc: Dave Hansen 
Cc: Andy Lutomirski 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: "H. Peter Anvin" 
Cc: Vishal Verma 
Cc: Dave Jiang 
Cc: Baoquan He 
Cc: Chuhong Yuan 
Cc: Mike Rapoport 
Cc: Logan Gunthorpe 
Cc: Masahiro Yamada 
Cc: Jonathan Cameron 
Cc: Kaly Xin 
Link: http://lkml.kernel.org/r/20200710031619.18762-2-justin.he@arm.com
Signed-off-by: Linus Torvalds

mm/memory_hotplug: document why shuffle_zone() is relevant

2020-08-07T18:33:29+00:00

It's not completely obvious why we have to shuffle the complete zone -
introduced in commit e900a918b098 ("mm: shuffle initial free memory to
improve memory-side-cache utilization") - because some sort of shuffling
is already performed when onlining pages via __free_one_page(), placing
MAX_ORDER-1 pages either to the head or the tail of the freelist.  Let's
document why we have to shuffle the complete zone when exposing larger,
contiguous physical memory areas to the buddy.

Signed-off-by: David Hildenbrand 
Signed-off-by: Andrew Morton 
Acked-by: Dan Williams 
Acked-by: Michal Hocko 
Cc: Alexander Duyck 
Cc: Dan Williams 
Cc: Michal Hocko 
Link: http://lkml.kernel.org/r/20200624094741.9918-3-david@redhat.com
Signed-off-by: Linus Torvalds

mm: remove vm_total_pages

2020-08-07T18:33:28+00:00

The global variable "vm_total_pages" is a relic from older days.  There is
only a single user that reads the variable - build_all_zonelists() - and
the first thing it does is update it.

Use a local variable in build_all_zonelists() instead and remove the
global variable.

Signed-off-by: David Hildenbrand 
Signed-off-by: Andrew Morton 
Reviewed-by: Wei Yang 
Reviewed-by: Pankaj Gupta 
Reviewed-by: Mike Rapoport 
Acked-by: Michal Hocko 
Cc: Johannes Weiner 
Cc: Huang Ying 
Cc: Minchan Kim 
Link: http://lkml.kernel.org/r/20200619132410.23859-2-david@redhat.com
Signed-off-by: Linus Torvalds

mm/memory_hotplug.c: fix false softlockup during pfn range removal

2020-06-26T07:27:38+00:00

When working with very large nodes, poisoning the struct pages (for which
there will be very many) can take a very long time.  If the system is
using voluntary preemptions, the software watchdog will not be able to
detect forward progress.  This patch addresses this issue by offering to
give up time like __remove_pages() does.  This behavior was introduced in
v5.6 with: commit d33695b16a9f ("mm/memory_hotplug: poison memmap in
remove_pfn_range_from_zone()")

Alternately, init_page_poison could do this cond_resched(), but it seems
to me that the caller of init_page_poison() is what actually knows whether
or not it should relax its own priority.

Based on Dan's notes, I think this is perfectly safe: commit f931ab479dd2
("mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done}")

Aside from fixing the lockup, it is also a friendlier thing to do on lower
core systems that might wipe out large chunks of hotplug memory (probably
not a very common case).

Fixes this kind of splat:

  watchdog: BUG: soft lockup - CPU#46 stuck for 22s! [daxctl:9922]
  irq event stamp: 138450
  hardirqs last  enabled at (138449): [] trace_hardirqs_on_thunk+0x1a/0x1c
  hardirqs last disabled at (138450): [] trace_hardirqs_off_thunk+0x1a/0x1c
  softirqs last  enabled at (138448): [] __do_softirq+0x347/0x456
  softirqs last disabled at (138443): [] irq_exit+0x7d/0xb0
  CPU: 46 PID: 9922 Comm: daxctl Not tainted 5.7.0-BEN-14238-g373c6049b336 #30
  Hardware name: Intel Corporation PURLEY/PURLEY, BIOS PLYXCRB1.86B.0578.D07.1902280810 02/28/2019
  RIP: 0010:memset_erms+0x9/0x10
  Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1  aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
  Call Trace:
   remove_pfn_range_from_zone+0x3a/0x380
   memunmap_pages+0x17f/0x280
   release_nodes+0x22a/0x260
   __device_release_driver+0x172/0x220
   device_driver_detach+0x3e/0xa0
   unbind_store+0x113/0x130
   kernfs_fop_write+0xdc/0x1c0
   vfs_write+0xde/0x1d0
   ksys_write+0x58/0xd0
   do_syscall_64+0x5a/0x120
   entry_SYSCALL_64_after_hwframe+0x49/0xb3
  Built 2 zonelists, mobility grouping on.  Total pages: 49050381
  Policy zone: Normal
  Built 3 zonelists, mobility grouping on.  Total pages: 49312525
  Policy zone: Normal

David said: "It really only is an issue for devmem.  Ordinary
hotplugged system memory is not affected (onlined/offlined in memory
block granularity)."

Link: http://lkml.kernel.org/r/20200619231213.1160351-1-ben.widawsky@intel.com
Fixes: commit d33695b16a9f ("mm/memory_hotplug: poison memmap in remove_pfn_range_from_zone()")
Signed-off-by: Ben Widawsky 
Reported-by: "Scargall, Steve" 
Reported-by: Ben Widawsky 
Acked-by: David Hildenbrand 
Cc: Dan Williams 
Cc: Vishal Verma 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2020-06-10T20:42:09+00:00

Pull virtio updates from Michael Tsirkin:

 - virtio-mem: paravirtualized memory hotplug

 - support doorbell mapping for vdpa

 - config interrupt support in ifc

 - fixes all over the place

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (40 commits)
  vhost/test: fix up after API change
  virtio_mem: convert device block size into 64bit
  virtio-mem: drop unnecessary initialization
  ifcvf: implement config interrupt in IFCVF
  vhost: replace -1 with VHOST_FILE_UNBIND in ioctls
  vhost_vdpa: Support config interrupt in vdpa
  ifcvf: ignore continuous setting same status value
  virtio-mem: Don't rely on implicit compiler padding for requests
  virtio-mem: Try to unplug the complete online memory block first
  virtio-mem: Use -ETXTBSY as error code if the device is busy
  virtio-mem: Unplug subblocks right-to-left
  virtio-mem: Drop manual check for already present memory
  virtio-mem: Add parent resource for all added "System RAM"
  virtio-mem: Better retry handling
  virtio-mem: Offline and remove completely unplugged memory blocks
  mm/memory_hotplug: Introduce offline_and_remove_memory()
  virtio-mem: Allow to offline partially unplugged memory blocks
  mm: Allow to offline unmovable PageOffline() pages via MEM_GOING_OFFLINE
  virtio-mem: Paravirtualized memory hotunplug part 2
  virtio-mem: Paravirtualized memory hotunplug part 1
  ...

mm/memory_hotplug: fix a typo in comment "recoreded"->"recorded"

2020-06-05T02:06:23+00:00

There is a typo in comment, fix it.
s/recoreded/recorded

Signed-off-by: Ethon Paul 
Signed-off-by: Andrew Morton 
Reviewed-by: Andrew Morton 
Reviewed-by: Ralph Campbell 
Link: http://lkml.kernel.org/r/20200410160328.13843-1-ethp@qq.com
Signed-off-by: Linus Torvalds