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294 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Fan Du
|
1b7176aea0 |
memory hotplug: fix comments when adding section
Here, pfn_to_node should be page_to_nid. Link: http://lkml.kernel.org/r/1510735205-22540-1-git-send-email-fan.du@intel.com Signed-off-by: Fan Du <fan.du@intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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ecde0f3e7f |
mm, memory_hotplug: remove timeout from __offline_memory
We have a hardcoded 120s timeout after which the memory offline fails basically since the hot remove has been introduced. This is essentially a policy implemented in the kernel. Moreover there is no way to adjust the timeout and so we are sometimes facing memory offline failures if the system is under a heavy memory pressure or very intensive CPU workload on large machines. It is not very clear what purpose the timeout actually serves. The offline operation is interruptible by a signal so if userspace wants some timeout based termination this can be done trivially by sending a signal. If there is a strong usecase to do this from the kernel then we should do it properly and have a it tunable from the userspace with the timeout disabled by default along with the explanation who uses it and for what purporse. Link: http://lkml.kernel.org/r/20170918070834.13083-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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72b39cfc4d |
mm, memory_hotplug: do not fail offlining too early
Patch series "mm, memory_hotplug: redefine memory offline retry logic", v2. While testing memory hotplug on a large 4TB machine we have noticed that memory offlining is just too eager to fail. The primary reason is that the retry logic is just too easy to give up. We have 4 ways out of the offline - we have a permanent failure (isolation or memory notifiers fail, or hugetlb pages cannot be dropped) - userspace sends a signal - a hardcoded 120s timeout expires - page migration fails 5 times This is way too convoluted and it doesn't scale very well. We have seen both temporary migration failures as well as 120s being triggered. After removing those restrictions we were able to pass stress testing during memory hot remove without any other negative side effects observed. Therefore I suggest dropping both hard coded policies. I couldn't have found any specific reason for them in the changelog. I neither didn't get any response [1] from Kamezawa. If we need some upper bound - e.g. timeout based - then we should have a proper and user defined policy for that. In any case there should be a clear use case when introducing it. This patch (of 2): Memory offlining can fail too eagerly under heavy memory pressure. page:ffffea22a646bd00 count:255 mapcount:252 mapping:ffff88ff926c9f38 index:0x3 flags: 0x9855fe40010048(uptodate|active|mappedtodisk) page dumped because: isolation failed page->mem_cgroup:ffff8801cd662000 memory offlining [mem 0x18b580000000-0x18b5ffffffff] failed Isolation has failed here because the page is not on LRU. Most probably because it was on the pcp LRU cache or it has been removed from the LRU already but it hasn't been freed yet. In both cases the page doesn't look non-migrable so retrying more makes sense. __offline_pages seems rather cluttered when it comes to the retry logic. We have 5 retries at maximum and a timeout. We could argue whether the timeout makes sense but failing just because of a race when somebody isoltes a page from LRU or puts it on a pcp LRU lists is just wrong. It only takes it to race with a process which unmaps some pages and remove them from the LRU list and we can fail the whole offline because of something that is a temporary condition and actually not harmful for the offline. Please note that unmovable pages should be already excluded during start_isolate_page_range. We could argue that has_unmovable_pages is racy and MIGRATE_MOVABLE check doesn't provide any hard guarantee either but kernel zones (aka < ZONE_MOVABLE) will very likely detect unmovable pages in most cases and movable zone shouldn't contain unmovable pages at all. Some of those pages might be pinned but not for ever because that would be a bug on its own. In any case the context is still interruptible and so the userspace can easily bail out when the operation takes too long. This is certainly better behavior than a hardcoded retry loop which is racy. Fix this by removing the max retry count and only rely on the timeout resp. interruption by a signal from the userspace. Also retry rather than fail when check_pages_isolated sees some !free pages because those could be a result of the race as well. Link: http://lkml.kernel.org/r/20170918070834.13083-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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YASUAKI ISHIMATSU
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d09b0137d2 |
mm/memory_hotplug: define find_{smallest|biggest}_section_pfn as unsigned long
find_{smallest|biggest}_section_pfn()s find the smallest/biggest section
and return the pfn of the section. But the functions are defined as int.
So the functions always return 0x00000000 - 0xffffffff. It means if
memory address is over 16TB, the functions does not work correctly.
To handle 64 bit value, the patch defines
find_{smallest|biggest}_section_pfn() as unsigned long.
Fixes:
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YASUAKI ISHIMATSU
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1dd2bfc868 |
mm/memory_hotplug: change pfn_to_section_nr/section_nr_to_pfn macro to inline function
pfn_to_section_nr() and section_nr_to_pfn() are defined as macro.
pfn_to_section_nr() has no issue even if it is defined as macro. But
section_nr_to_pfn() has overflow issue if sec is defined as int.
section_nr_to_pfn() just shifts sec by PFN_SECTION_SHIFT. If sec is
defined as unsigned long, section_nr_to_pfn() returns pfn as 64 bit value.
But if sec is defined as int, section_nr_to_pfn() returns pfn as 32 bit
value.
__remove_section() calculates start_pfn using section_nr_to_pfn() and
scn_nr defined as int. So if hot-removed memory address is over 16TB,
overflow issue occurs and section_nr_to_pfn() does not calculate correct
pfn.
To make callers use proper arg, the patch changes the macros to inline
functions.
Fixes:
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Michal Hocko
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f64ac5e6e3 |
mm, memory_hotplug: add scheduling point to __add_pages
Patch series "mm, memory_hotplug: fix few soft lockups in memory
hotadd".
Johannes has noticed few soft lockups when adding a large nvdimm device.
All of them were caused by a long loop without any explicit cond_resched
which is a problem for !PREEMPT kernels.
The fix is quite straightforward. Just make sure that cond_resched gets
called from time to time.
This patch (of 3):
__add_pages gets a pfn range to add and there is no upper bound for a
single call. This is usually a memory block aligned size for the
regular memory hotplug - smaller sizes are usual for memory balloning
drivers, or the whole NUMA node for physical memory online. There is no
explicit scheduling point in that code path though.
This can lead to long latencies while __add_pages is executed and we
have even seen a soft lockup report during nvdimm initialization with
!PREEMPT kernel
NMI watchdog: BUG: soft lockup - CPU#11 stuck for 23s! [kworker/u641:3:832]
[...]
Workqueue: events_unbound async_run_entry_fn
task: ffff881809270f40 ti: ffff881809274000 task.ti: ffff881809274000
RIP: _raw_spin_unlock_irqrestore+0x11/0x20
RSP: 0018:ffff881809277b10 EFLAGS: 00000286
[...]
Call Trace:
sparse_add_one_section+0x13d/0x18e
__add_pages+0x10a/0x1d0
arch_add_memory+0x4a/0xc0
devm_memremap_pages+0x29d/0x430
pmem_attach_disk+0x2fd/0x3f0 [nd_pmem]
nvdimm_bus_probe+0x64/0x110 [libnvdimm]
driver_probe_device+0x1f7/0x420
bus_for_each_drv+0x52/0x80
__device_attach+0xb0/0x130
bus_probe_device+0x87/0xa0
device_add+0x3fc/0x5f0
nd_async_device_register+0xe/0x40 [libnvdimm]
async_run_entry_fn+0x43/0x150
process_one_work+0x14e/0x410
worker_thread+0x116/0x490
kthread+0xc7/0xe0
ret_from_fork+0x3f/0x70
DWARF2 unwinder stuck at ret_from_fork+0x3f/0x70
Fix this by adding cond_resched once per each memory section in the
given pfn range. Each section is constant amount of work which itself
is not too expensive but many of them will just add up.
Link: http://lkml.kernel.org/r/20170918121410.24466-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Johannes Thumshirn <jthumshirn@suse.de>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Dan Williams <dan.j.williams@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jérôme Glisse
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5042db43cc |
mm/ZONE_DEVICE: new type of ZONE_DEVICE for unaddressable memory
HMM (heterogeneous memory management) need struct page to support migration from system main memory to device memory. Reasons for HMM and migration to device memory is explained with HMM core patch. This patch deals with device memory that is un-addressable memory (ie CPU can not access it). Hence we do not want those struct page to be manage like regular memory. That is why we extend ZONE_DEVICE to support different types of memory. A persistent memory type is define for existing user of ZONE_DEVICE and a new device un-addressable type is added for the un-addressable memory type. There is a clear separation between what is expected from each memory type and existing user of ZONE_DEVICE are un-affected by new requirement and new use of the un-addressable type. All specific code path are protect with test against the memory type. Because memory is un-addressable we use a new special swap type for when a page is migrated to device memory (this reduces the number of maximum swap file). The main two additions beside memory type to ZONE_DEVICE is two callbacks. First one, page_free() is call whenever page refcount reach 1 (which means the page is free as ZONE_DEVICE page never reach a refcount of 0). This allow device driver to manage its memory and associated struct page. The second callback page_fault() happens when there is a CPU access to an address that is back by a device page (which are un-addressable by the CPU). This callback is responsible to migrate the page back to system main memory. Device driver can not block migration back to system memory, HMM make sure that such page can not be pin into device memory. If device is in some error condition and can not migrate memory back then a CPU page fault to device memory should end with SIGBUS. [arnd@arndb.de: fix warning] Link: http://lkml.kernel.org/r/20170823133213.712917-1-arnd@arndb.de Link: http://lkml.kernel.org/r/20170817000548.32038-8-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Nellans <dnellans@nvidia.com> Cc: Evgeny Baskakov <ebaskakov@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mark Hairgrove <mhairgrove@nvidia.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Sherry Cheung <SCheung@nvidia.com> Cc: Subhash Gutti <sgutti@nvidia.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Naoya Horiguchi
|
8135d8926c |
mm: memory_hotplug: memory hotremove supports thp migration
This patch enables thp migration for memory hotremove. Link: http://lkml.kernel.org/r/20170717193955.20207-11-zi.yan@sent.com Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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b93e0f329e |
mm, memory_hotplug: get rid of zonelists_mutex
zonelists_mutex was introduced by commit |
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Michal Hocko
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34ad129657 |
mm, memory_hotplug: remove explicit build_all_zonelists from try_online_node
try_online_node calls hotadd_new_pgdat which already calls build_all_zonelists. So the additional call is redundant. Even though hotadd_new_pgdat will only initialize zonelists of the new node this is the right thing to do because such a node doesn't have any memory so other zonelists would ignore all the zones from this node anyway. Link: http://lkml.kernel.org/r/20170721143915.14161-6-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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72675e131e |
mm, memory_hotplug: drop zone from build_all_zonelists
build_all_zonelists gets a zone parameter to initialize zone's pagesets.
There is only a single user which gives a non-NULL zone parameter and
that one doesn't really need the rest of the build_all_zonelists (see
commit
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Michal Hocko
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c6f03e2903 |
mm, memory_hotplug: remove zone restrictions
Historically we have enforced that any kernel zone (e.g ZONE_NORMAL) has
to precede the Movable zone in the physical memory range. The purpose
of the movable zone is, however, not bound to any physical memory
restriction. It merely defines a class of migrateable and reclaimable
memory.
There are users (e.g. CMA) who might want to reserve specific physical
memory ranges for their own purpose. Moreover our pfn walkers have to
be prepared for zones overlapping in the physical range already because
we do support interleaving NUMA nodes and therefore zones can interleave
as well. This means we can allow each memory block to be associated
with a different zone.
Loosen the current onlining semantic and allow explicit onlining type on
any memblock. That means that online_{kernel,movable} will be allowed
regardless of the physical address of the memblock as long as it is
offline of course. This might result in moveble zone overlapping with
other kernel zones. Default onlining then becomes a bit tricky but
still sensible. echo online > memoryXY/state will online the given
block to
1) the default zone if the given range is outside of any zone
2) the enclosing zone if such a zone doesn't interleave with
any other zone
3) the default zone if more zones interleave for this range
where default zone is movable zone only if movable_node is enabled
otherwise it is a kernel zone.
Here is an example of the semantic with (movable_node is not present but
it work in an analogous way). We start with following memblocks, all of
them offline:
memory34/valid_zones:Normal Movable
memory35/valid_zones:Normal Movable
memory36/valid_zones:Normal Movable
memory37/valid_zones:Normal Movable
memory38/valid_zones:Normal Movable
memory39/valid_zones:Normal Movable
memory40/valid_zones:Normal Movable
memory41/valid_zones:Normal Movable
Now, we online block 34 in default mode and block 37 as movable
root@test1:/sys/devices/system/node/node1# echo online > memory34/state
root@test1:/sys/devices/system/node/node1# echo online_movable > memory37/state
memory34/valid_zones:Normal
memory35/valid_zones:Normal Movable
memory36/valid_zones:Normal Movable
memory37/valid_zones:Movable
memory38/valid_zones:Normal Movable
memory39/valid_zones:Normal Movable
memory40/valid_zones:Normal Movable
memory41/valid_zones:Normal Movable
As we can see all other blocks can still be onlined both into Normal and
Movable zones and the Normal is default because the Movable zone spans
only block37 now.
root@test1:/sys/devices/system/node/node1# echo online_movable > memory41/state
memory34/valid_zones:Normal
memory35/valid_zones:Normal Movable
memory36/valid_zones:Normal Movable
memory37/valid_zones:Movable
memory38/valid_zones:Movable Normal
memory39/valid_zones:Movable Normal
memory40/valid_zones:Movable Normal
memory41/valid_zones:Movable
Now the default zone for blocks 37-41 has changed because movable zone
spans that range.
root@test1:/sys/devices/system/node/node1# echo online_kernel > memory39/state
memory34/valid_zones:Normal
memory35/valid_zones:Normal Movable
memory36/valid_zones:Normal Movable
memory37/valid_zones:Movable
memory38/valid_zones:Normal Movable
memory39/valid_zones:Normal
memory40/valid_zones:Movable Normal
memory41/valid_zones:Movable
Note that the block 39 now belongs to the zone Normal and so block38
falls into Normal by default as well.
For completness
root@test1:/sys/devices/system/node/node1# for i in memory[34]?
do
echo online > $i/state 2>/dev/null
done
memory34/valid_zones:Normal
memory35/valid_zones:Normal
memory36/valid_zones:Normal
memory37/valid_zones:Movable
memory38/valid_zones:Normal
memory39/valid_zones:Normal
memory40/valid_zones:Movable
memory41/valid_zones:Movable
Implementation wise the change is quite straightforward. We can get rid
of allow_online_pfn_range altogether. online_pages allows only offline
nodes already. The original default_zone_for_pfn will become
default_kernel_zone_for_pfn. New default_zone_for_pfn implements the
above semantic. zone_for_pfn_range is slightly reorganized to implement
kernel and movable online type explicitly and MMOP_ONLINE_KEEP becomes a
catch all default behavior.
Link: http://lkml.kernel.org/r/20170714121233.16861-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Kani Toshimitsu <toshi.kani@hpe.com>
Cc: <slaoub@gmail.com>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: <linux-api@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Michal Hocko
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e5e6893026 |
mm, memory_hotplug: display allowed zones in the preferred ordering
Prior to commit
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Thomas Gleixner
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3f906ba236 |
mm/memory-hotplug: switch locking to a percpu rwsem
Andrey reported a potential deadlock with the memory hotplug lock and the cpu hotplug lock. The reason is that memory hotplug takes the memory hotplug lock and then calls stop_machine() which calls get_online_cpus(). That's the reverse lock order to get_online_cpus(); get_online_mems(); in mm/slub_common.c The problem has been there forever. The reason why this was never reported is that the cpu hotplug locking had this homebrewn recursive reader writer semaphore construct which due to the recursion evaded the full lock dep coverage. The memory hotplug code copied that construct verbatim and therefor has similar issues. Three steps to fix this: 1) Convert the memory hotplug locking to a per cpu rwsem so the potential issues get reported proper by lockdep. 2) Lock the online cpus in mem_hotplug_begin() before taking the memory hotplug rwsem and use stop_machine_cpuslocked() in the page_alloc code to avoid recursive locking. 3) The cpu hotpluck locking in #2 causes a recursive locking of the cpu hotplug lock via __offline_pages() -> lru_add_drain_all(). Solve this by invoking lru_add_drain_all_cpuslocked() instead. Link: http://lkml.kernel.org/r/20170704093421.506836322@linutronix.de Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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John Hubbard
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a52149f129 |
mm/memory_hotplug.c: remove unused local zone_type from __remove_zone()
__remove_zone() sets up up zone_type, but never uses it for anything. This does not cause a warning, due to the (necessary) use of -Wno-unused-but-set-variable. However, it's noise, so just delete it. Link: http://lkml.kernel.org/r/20170624043421.24465-2-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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8b91323889 |
mm: unify new_node_page and alloc_migrate_target
Commit
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Michal Hocko
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4db9b2efe9 |
hugetlb, memory_hotplug: prefer to use reserved pages for migration
new_node_page will try to use the origin's next NUMA node as the migration destination for hugetlb pages. If such a node doesn't have any preallocated pool it falls back to __alloc_buddy_huge_page_no_mpol to allocate a surplus page instead. This is quite subotpimal for any configuration when hugetlb pages are no distributed to all NUMA nodes evenly. Say we have a hotplugable node 4 and spare hugetlb pages are node 0 /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages:10000 /sys/devices/system/node/node1/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node2/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node3/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node4/hugepages/hugepages-2048kB/nr_hugepages:10000 /sys/devices/system/node/node5/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node6/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node7/hugepages/hugepages-2048kB/nr_hugepages:0 Now we consume the whole pool on node 4 and try to offline this node. All the allocated pages should be moved to node0 which has enough preallocated pages to hold them. With the current implementation offlining very likely fails because hugetlb allocations during runtime are much less reliable. Fix this by reusing the nodemask which excludes migration source and try to find a first node which has a page in the preallocated pool first and fall back to __alloc_buddy_huge_page_no_mpol only when the whole pool is consumed. [akpm@linux-foundation.org: remove bogus arg from alloc_huge_page_nodemask() stub] Link: http://lkml.kernel.org/r/20170608074553.22152-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: zhong jiang <zhongjiang@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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7f252f277b |
mm, memory_hotplug: simplify empty node mask handling in new_node_page
new_node_page tries to allocate the target page on a different NUMA node than the source page. This makes sense in most cases during the hotplug because we are likely to offline the whole numa node. But there are cases where there are no other nodes to fallback (e.g. when offlining parts of the only existing node) and we have to fallback to allocating from the source node. The current code does that but it can be simplified by checking the nmask and updating it before we even try to allocate rather than special casing it. This patch shouldn't introduce any functional change. Link: http://lkml.kernel.org/r/20170608074553.22152-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: zhong jiang <zhongjiang@huawei.com> Cc: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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9f123ab544 |
mm, memory_hotplug: support movable_node for hotpluggable nodes
movable_node kernel parameter allows making hotpluggable NUMA nodes to put all the hotplugable memory into movable zone which allows more or less reliable memory hotremove. At least this is the case for the NUMA nodes present during the boot (see find_zone_movable_pfns_for_nodes). This is not the case for the memory hotplug, though. echo online > /sys/devices/system/memory/memoryXYZ/state will default to a kernel zone (usually ZONE_NORMAL) unless the particular memblock is already in the movable zone range which is not the case normally when onlining the memory from the udev rule context for a freshly hotadded NUMA node. The only option currently is to have a special udev rule to echo online_movable to all memblocks belonging to such a node which is rather clumsy. Not to mention this is inconsistent as well because what ended up in the movable zone during the boot will end up in a kernel zone after hotremove & hotadd without special care. It would be nice to reuse memblock_is_hotpluggable but the runtime hotplug doesn't have that information available because the boot and hotplug paths are not shared and it would be really non trivial to make them use the same code path because the runtime hotplug doesn't play with the memblock allocator at all. Teach move_pfn_range that MMOP_ONLINE_KEEP can use the movable zone if movable_node is enabled and the range doesn't overlap with the existing normal zone. This should provide a reasonable default onlining strategy. Strictly speaking the semantic is not identical with the boot time initialization because find_zone_movable_pfns_for_nodes covers only the hotplugable range as described by the BIOS/FW. From my experience this is usually a full node though (except for Node0 which is special and never goes away completely). If this turns out to be a problem in the real life we can tweak the code to store hotplug flag into memblocks but let's keep this simple now. Link: http://lkml.kernel.org/r/20170612111227.GI7476@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Cc: <qiuxishi@huawei.com> Cc: Kani Toshimitsu <toshi.kani@hpe.com> Cc: <slaoub@gmail.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Gustavo A. R. Silva
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dbac61a3f2 |
mm/memory_hotplug.c: add NULL check to avoid potential NULL pointer dereference
The NULL check at line 1226: if (!pgdat), implies that pointer pgdat might be NULL. rollback_node_hotadd() dereferences this pointer. Add NULL check to avoid a potential NULL pointer dereference. Addresses-Coverity-ID: 1369133 Link: http://lkml.kernel.org/r/20170530212436.GA6195@embeddedgus Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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4932381ee2 |
mm, memory_hotplug: move movable_node to the hotplug proper
movable_node_is_enabled is defined in memblock proper while it is initialized from the memory hotplug proper. This is quite messy and it makes a dependency between the two so move movable_node along with the helper functions to memory_hotplug. To make it more entertaining the kernel parameter is ignored unless CONFIG_HAVE_MEMBLOCK_NODE_MAP=y because we do not have the node information for each memblock otherwise. So let's warn when the option is disabled. Link: http://lkml.kernel.org/r/20170529114141.536-4-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Reza Arbab <arbab@linux.vnet.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Kani Toshimitsu <toshi.kani@hpe.com> Cc: Chen Yucong <slaoub@gmail.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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f70029bbaa |
mm, memory_hotplug: drop CONFIG_MOVABLE_NODE
Commit
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Michal Hocko
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57c0a17238 |
mm, memory_hotplug: drop artificial restriction on online/offline
Patch series "remove CONFIG_MOVABLE_NODE".
I am continuing to clean up the memory hotplug code and
CONFIG_MOVABLE_NODE seems dubious at best. The following two patches
simply removes the flag and make it de-facto always enabled.
The current semantic of the config option is twofold 1) it automatically
binds hotplugable nodes to have memory in zone_movable by default when
movable_node is enabled 2) forbids memory hotplug to online all the
memory as movable when !CONFIG_MOVABLE_NODE.
The later restriction is quite dubious because there is no clear cut of
how much normal memory do we need for a reasonable system operation. A
single memory block which is sufficient to allow further movable onlines
is far from sufficient (e.g a node with >2GB and memblocks 128MB will
fill up this zone with struct pages leaving nothing for other
allocations). Removing the config option will not only reduce the
configuration space it also removes quite some code.
The semantic of the movable_node command line parameter is preserved.
The first patch removes the restriction mentioned above and the second
one simply removes all the CONFIG_MOVABLE_NODE related stuff. The last
patch moves movable_node flag handling to memory_hotplug proper where it
belongs.
[1] http://lkml.kernel.org/r/20170524122411.25212-1-mhocko@kernel.org
This patch (of 3):
Commit
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Vlastimil Babka
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04ec6264f2 |
mm, page_alloc: pass preferred nid instead of zonelist to allocator
The main allocator function __alloc_pages_nodemask() takes a zonelist pointer as one of its parameters. All of its callers directly or indirectly obtain the zonelist via node_zonelist() using a preferred node id and gfp_mask. We can make the code a bit simpler by doing the zonelist lookup in __alloc_pages_nodemask(), passing it a preferred node id instead (gfp_mask is already another parameter). There are some code size benefits thanks to removal of inlined node_zonelist(): bloat-o-meter add/remove: 2/2 grow/shrink: 4/36 up/down: 399/-1351 (-952) This will also make things simpler if we proceed with converting cpusets to zonelists. Link: http://lkml.kernel.org/r/20170517081140.30654-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Christoph Lameter <cl@linux.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Michal Hocko
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559bfc7d1b |
mm, memory_hotplug: remove unused cruft after memory hotplug rework
zone_for_memory doesn't have any user anymore as well as the whole zone shifting infrastructure so drop them all. This shouldn't introduce any functional changes. Link: http://lkml.kernel.org/r/20170515085827.16474-15-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Tobias Regnery <tobias.regnery@gmail.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |