forked from Minki/linux
8a48ac3393
1520 Commits
Author | SHA1 | Message | Date | |
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David Rientjes
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3f36d86694 |
mm, hugetlb: allow hugepage allocations to reclaim as needed
Commit |
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Qian Cai
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234fdce892 |
mm/page_alloc.c: fix a crash in free_pages_prepare()
On architectures like s390, arch_free_page() could mark the page unused (set_page_unused()) and any access later would trigger a kernel panic. Fix it by moving arch_free_page() after all possible accessing calls. Hardware name: IBM 2964 N96 400 (z/VM 6.4.0) Krnl PSW : 0404e00180000000 0000000026c2b96e (__free_pages_ok+0x34e/0x5d8) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3 Krnl GPRS: 0000000088d43af7 0000000000484000 000000000000007c 000000000000000f 000003d080012100 000003d080013fc0 0000000000000000 0000000000100000 00000000275cca48 0000000000000100 0000000000000008 000003d080010000 00000000000001d0 000003d000000000 0000000026c2b78a 000000002717fdb0 Krnl Code: 0000000026c2b95c: ec1100b30659 risbgn %r1,%r1,0,179,6 0000000026c2b962: e32014000036 pfd 2,1024(%r1) #0000000026c2b968: d7ff10001000 xc 0(256,%r1),0(%r1) >0000000026c2b96e: 41101100 la %r1,256(%r1) 0000000026c2b972: a737fff8 brctg %r3,26c2b962 0000000026c2b976: d7ff10001000 xc 0(256,%r1),0(%r1) 0000000026c2b97c: e31003400004 lg %r1,832 0000000026c2b982: ebff1430016a asi 5168(%r1),-1 Call Trace: __free_pages_ok+0x16a/0x5d8) memblock_free_all+0x206/0x290 mem_init+0x58/0x120 start_kernel+0x2b0/0x570 startup_continue+0x6a/0xc0 INFO: lockdep is turned off. Last Breaking-Event-Address: __free_pages_ok+0x372/0x5d8 Kernel panic - not syncing: Fatal exception: panic_on_oops 00: HCPGIR450W CP entered; disabled wait PSW 00020001 80000000 00000000 26A2379C In the past, only kernel_poison_pages() would trigger this but it needs "page_poison=on" kernel cmdline, and I suspect nobody tested that on s390. Recently, kernel_init_free_pages() (commit |
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Linus Torvalds
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edf445ad7c |
Merge branch 'hugepage-fallbacks' (hugepatch patches from David Rientjes)
Merge hugepage allocation updates from David Rientjes: "We (mostly Linus, Andrea, and myself) have been discussing offlist how to implement a sane default allocation strategy for hugepages on NUMA platforms. With these reverts in place, the page allocator will happily allocate a remote hugepage immediately rather than try to make a local hugepage available. This incurs a substantial performance degradation when memory compaction would have otherwise made a local hugepage available. This series reverts those reverts and attempts to propose a more sane default allocation strategy specifically for hugepages. Andrea acknowledges this is likely to fix the swap storms that he originally reported that resulted in the patches that removed __GFP_THISNODE from hugepage allocations. The immediate goal is to return 5.3 to the behavior the kernel has implemented over the past several years so that remote hugepages are not immediately allocated when local hugepages could have been made available because the increased access latency is untenable. The next goal is to introduce a sane default allocation strategy for hugepages allocations in general regardless of the configuration of the system so that we prevent thrashing of local memory when compaction is unlikely to succeed and can prefer remote hugepages over remote native pages when the local node is low on memory." Note on timing: this reverts the hugepage VM behavior changes that got introduced fairly late in the 5.3 cycle, and that fixed a huge performance regression for certain loads that had been around since 4.18. Andrea had this note: "The regression of 4.18 was that it was taking hours to start a VM where 3.10 was only taking a few seconds, I reported all the details on lkml when it was finally tracked down in August 2018. https://lore.kernel.org/linux-mm/20180820032640.9896-2-aarcange@redhat.com/ __GFP_THISNODE in MADV_HUGEPAGE made the above enterprise vfio workload degrade like in the "current upstream" above. And it still would have been that bad as above until 5.3-rc5" where the bad behavior ends up happening as you fill up a local node, and without that change, you'd get into the nasty swap storm behavior due to compaction working overtime to make room for more memory on the nodes. As a result 5.3 got the two performance fix reverts in rc5. However, David Rientjes then noted that those performance fixes in turn regressed performance for other loads - although not quite to the same degree. He suggested reverting the reverts and instead replacing them with two small changes to how hugepage allocations are done (patch descriptions rephrased by me): - "avoid expensive reclaim when compaction may not succeed": just admit that the allocation failed when you're trying to allocate a huge-page and compaction wasn't successful. - "allow hugepage fallback to remote nodes when madvised": when that node-local huge-page allocation failed, retry without forcing the local node. but by then I judged it too late to replace the fixes for a 5.3 release. So 5.3 was released with behavior that harked back to the pre-4.18 logic. But now we're in the merge window for 5.4, and we can see if this alternate model fixes not just the horrendous swap storm behavior, but also restores the performance regression that the late reverts caused. Fingers crossed. * emailed patches from David Rientjes <rientjes@google.com>: mm, page_alloc: allow hugepage fallback to remote nodes when madvised mm, page_alloc: avoid expensive reclaim when compaction may not succeed Revert "Revert "Revert "mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask"" Revert "Revert "mm, thp: restore node-local hugepage allocations"" |
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David Rientjes
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b39d0ee263 |
mm, page_alloc: avoid expensive reclaim when compaction may not succeed
Memory compaction has a couple significant drawbacks as the allocation order increases, specifically: - isolate_freepages() is responsible for finding free pages to use as migration targets and is implemented as a linear scan of memory starting at the end of a zone, - failing order-0 watermark checks in memory compaction does not account for how far below the watermarks the zone actually is: to enable migration, there must be *some* free memory available. Per the above, watermarks are not always suffficient if isolate_freepages() cannot find the free memory but it could require hundreds of MBs of reclaim to even reach this threshold (read: potentially very expensive reclaim with no indication compaction can be successful), and - if compaction at this order has failed recently so that it does not even run as a result of deferred compaction, looping through reclaim can often be pointless. For hugepage allocations, these are quite substantial drawbacks because these are very high order allocations (order-9 on x86) and falling back to doing reclaim can potentially be *very* expensive without any indication that compaction would even be successful. Reclaim itself is unlikely to free entire pageblocks and certainly no reliance should be put on it to do so in isolation (recall lumpy reclaim). This means we should avoid reclaim and simply fail hugepage allocation if compaction is deferred. It is also not helpful to thrash a zone by doing excessive reclaim if compaction may not be able to access that memory. If order-0 watermarks fail and the allocation order is sufficiently large, it is likely better to fail the allocation rather than thrashing the zone. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Yang Shi
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7ae88534cd |
mm: move mem_cgroup_uncharge out of __page_cache_release()
A later patch makes THP deferred split shrinker memcg aware, but it needs page->mem_cgroup information in THP destructor, which is called after mem_cgroup_uncharge() now. So move mem_cgroup_uncharge() from __page_cache_release() to compound page destructor, which is called by both THP and other compound pages except HugeTLB. And call it in __put_single_page() for single order page. Link: http://lkml.kernel.org/r/1565144277-36240-3-git-send-email-yang.shi@linux.alibaba.com Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Suggested-by: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Qian Cai <cai@lca.pw> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Yang Shi
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364c1eebe4 |
mm: thp: extract split_queue_* into a struct
Patch series "Make deferred split shrinker memcg aware", v6. Currently THP deferred split shrinker is not memcg aware, this may cause premature OOM with some configuration. For example the below test would run into premature OOM easily: $ cgcreate -g memory:thp $ echo 4G > /sys/fs/cgroup/memory/thp/memory/limit_in_bytes $ cgexec -g memory:thp transhuge-stress 4000 transhuge-stress comes from kernel selftest. It is easy to hit OOM, but there are still a lot THP on the deferred split queue, memcg direct reclaim can't touch them since the deferred split shrinker is not memcg aware. Convert deferred split shrinker memcg aware by introducing per memcg deferred split queue. The THP should be on either per node or per memcg deferred split queue if it belongs to a memcg. When the page is immigrated to the other memcg, it will be immigrated to the target memcg's deferred split queue too. Reuse the second tail page's deferred_list for per memcg list since the same THP can't be on multiple deferred split queues. Make deferred split shrinker not depend on memcg kmem since it is not slab. It doesn't make sense to not shrink THP even though memcg kmem is disabled. With the above change the test demonstrated above doesn't trigger OOM even though with cgroup.memory=nokmem. This patch (of 4): Put split_queue, split_queue_lock and split_queue_len into a struct in order to reduce code duplication when we convert deferred_split to memcg aware in the later patches. Link: http://lkml.kernel.org/r/1565144277-36240-2-git-send-email-yang.shi@linux.alibaba.com Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Suggested-by: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Qian Cai <cai@lca.pw> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
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4943308556 |
mm, compaction: raise compaction priority after it withdrawns
Mike Kravetz reports that "hugetlb allocations could stall for minutes or hours when should_compact_retry() would return true more often then it should. Specifically, this was in the case where compact_result was COMPACT_DEFERRED and COMPACT_PARTIAL_SKIPPED and no progress was being made." The problem is that the compaction_withdrawn() test in should_compact_retry() includes compaction outcomes that are only possible on low compaction priority, and results in a retry without increasing the priority. This may result in furter reclaim, and more incomplete compaction attempts. With this patch, compaction priority is raised when possible, or should_compact_retry() returns false. The COMPACT_SKIPPED result doesn't really fit together with the other outcomes in compaction_withdrawn(), as that's a result caused by insufficient order-0 pages, not due to low compaction priority. With this patch, it is moved to a new compaction_needs_reclaim() function, and for that outcome we keep the current logic of retrying if it looks like reclaim will be able to help. Link: http://lkml.kernel.org/r/20190806014744.15446-4-mike.kravetz@oracle.com Reported-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Tested-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> 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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Matthew Wilcox (Oracle)
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d8c6546b1a |
mm: introduce compound_nr()
Replace 1 << compound_order(page) with compound_nr(page). Minor improvements in readability. Link: http://lkml.kernel.org/r/20190721104612.19120-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: 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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Linus Torvalds
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84da111de0 |
hmm related patches for 5.4
This is more cleanup and consolidation of the hmm APIs and the very strongly related mmu_notifier interfaces. Many places across the tree using these interfaces are touched in the process. Beyond that a cleanup to the page walker API and a few memremap related changes round out the series: - General improvement of hmm_range_fault() and related APIs, more documentation, bug fixes from testing, API simplification & consolidation, and unused API removal - Simplify the hmm related kconfigs to HMM_MIRROR and DEVICE_PRIVATE, and make them internal kconfig selects - Hoist a lot of code related to mmu notifier attachment out of drivers by using a refcount get/put attachment idiom and remove the convoluted mmu_notifier_unregister_no_release() and related APIs. - General API improvement for the migrate_vma API and revision of its only user in nouveau - Annotate mmu_notifiers with lockdep and sleeping region debugging Two series unrelated to HMM or mmu_notifiers came along due to dependencies: - Allow pagemap's memremap_pages family of APIs to work without providing a struct device - Make walk_page_range() and related use a constant structure for function pointers -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfB7FMLh+8QxL+6i3OG33FX4gmxoFAl1/nnkACgkQOG33FX4g mxqaRg//c6FqowV1pQlLutvAOAgMdpzfZ9eaaDKngy9RVQxz+k/MmJrdRH/p/mMA Pq93A1XfwtraGKErHegFXGEDk4XhOustVAVFwvjyXO41dTUdoFVUkti6ftbrl/rS 6CT+X90jlvrwdRY7QBeuo7lxx7z8Qkqbk1O1kc1IOracjKfNJS+y6LTamy6weM3g tIMHI65PkxpRzN36DV9uCN5dMwFzJ73DWHp1b0acnDIigkl6u5zp6orAJVWRjyQX nmEd3/IOvdxaubAoAvboNS5CyVb4yS9xshWWMbH6AulKJv3Glca1Aa7QuSpBoN8v wy4c9+umzqRgzgUJUe1xwN9P49oBNhJpgBSu8MUlgBA4IOc3rDl/Tw0b5KCFVfkH yHkp8n6MP8VsRrzXTC6Kx0vdjIkAO8SUeylVJczAcVSyHIo6/JUJCVDeFLSTVymh EGWJ7zX2iRhUbssJ6/izQTTQyCH3YIyZ5QtqByWuX2U7ZrfkqS3/EnBW1Q+j+gPF Z2yW8iT6k0iENw6s8psE9czexuywa/Lttz94IyNlOQ8rJTiQqB9wLaAvg9hvUk7a kuspL+JGIZkrL3ouCeO/VA6xnaP+Q7nR8geWBRb8zKGHmtWrb5Gwmt6t+vTnCC2l olIDebrnnxwfBQhEJ5219W+M1pBpjiTpqK/UdBd92A4+sOOhOD0= =FRGg -----END PGP SIGNATURE----- Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma Pull hmm updates from Jason Gunthorpe: "This is more cleanup and consolidation of the hmm APIs and the very strongly related mmu_notifier interfaces. Many places across the tree using these interfaces are touched in the process. Beyond that a cleanup to the page walker API and a few memremap related changes round out the series: - General improvement of hmm_range_fault() and related APIs, more documentation, bug fixes from testing, API simplification & consolidation, and unused API removal - Simplify the hmm related kconfigs to HMM_MIRROR and DEVICE_PRIVATE, and make them internal kconfig selects - Hoist a lot of code related to mmu notifier attachment out of drivers by using a refcount get/put attachment idiom and remove the convoluted mmu_notifier_unregister_no_release() and related APIs. - General API improvement for the migrate_vma API and revision of its only user in nouveau - Annotate mmu_notifiers with lockdep and sleeping region debugging Two series unrelated to HMM or mmu_notifiers came along due to dependencies: - Allow pagemap's memremap_pages family of APIs to work without providing a struct device - Make walk_page_range() and related use a constant structure for function pointers" * tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (75 commits) libnvdimm: Enable unit test infrastructure compile checks mm, notifier: Catch sleeping/blocking for !blockable kernel.h: Add non_block_start/end() drm/radeon: guard against calling an unpaired radeon_mn_unregister() csky: add missing brackets in a macro for tlb.h pagewalk: use lockdep_assert_held for locking validation pagewalk: separate function pointers from iterator data mm: split out a new pagewalk.h header from mm.h mm/mmu_notifiers: annotate with might_sleep() mm/mmu_notifiers: prime lockdep mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end mm/mmu_notifiers: remove the __mmu_notifier_invalidate_range_start/end exports mm/hmm: hmm_range_fault() infinite loop mm/hmm: hmm_range_fault() NULL pointer bug mm/hmm: fix hmm_range_fault()'s handling of swapped out pages mm/mmu_notifiers: remove unregister_no_release RDMA/odp: remove ib_ucontext from ib_umem RDMA/odp: use mmu_notifier_get/put for 'struct ib_ucontext_per_mm' RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr RDMA/mlx5: Use ib_umem_start instead of umem.address ... |
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Linus Torvalds
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7e67a85999 |
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar: - MAINTAINERS: Add Mark Rutland as perf submaintainer, Juri Lelli and Vincent Guittot as scheduler submaintainers. Add Dietmar Eggemann, Steven Rostedt, Ben Segall and Mel Gorman as scheduler reviewers. As perf and the scheduler is getting bigger and more complex, document the status quo of current responsibilities and interests, and spread the review pain^H^H^H^H fun via an increase in the Cc: linecount generated by scripts/get_maintainer.pl. :-) - Add another series of patches that brings the -rt (PREEMPT_RT) tree closer to mainline: split the monolithic CONFIG_PREEMPT dependencies into a new CONFIG_PREEMPTION category that will allow the eventual introduction of CONFIG_PREEMPT_RT. Still a few more hundred patches to go though. - Extend the CPU cgroup controller with uclamp.min and uclamp.max to allow the finer shaping of CPU bandwidth usage. - Micro-optimize energy-aware wake-ups from O(CPUS^2) to O(CPUS). - Improve the behavior of high CPU count, high thread count applications running under cpu.cfs_quota_us constraints. - Improve balancing with SCHED_IDLE (SCHED_BATCH) tasks present. - Improve CPU isolation housekeeping CPU allocation NUMA locality. - Fix deadline scheduler bandwidth calculations and logic when cpusets rebuilds the topology, or when it gets deadline-throttled while it's being offlined. - Convert the cpuset_mutex to percpu_rwsem, to allow it to be used from setscheduler() system calls without creating global serialization. Add new synchronization between cpuset topology-changing events and the deadline acceptance tests in setscheduler(), which were broken before. - Rework the active_mm state machine to be less confusing and more optimal. - Rework (simplify) the pick_next_task() slowpath. - Improve load-balancing on AMD EPYC systems. - ... and misc cleanups, smaller fixes and improvements - please see the Git log for more details. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits) sched/psi: Correct overly pessimistic size calculation sched/fair: Speed-up energy-aware wake-ups sched/uclamp: Always use 'enum uclamp_id' for clamp_id values sched/uclamp: Update CPU's refcount on TG's clamp changes sched/uclamp: Use TG's clamps to restrict TASK's clamps sched/uclamp: Propagate system defaults to the root group sched/uclamp: Propagate parent clamps sched/uclamp: Extend CPU's cgroup controller sched/topology: Improve load balancing on AMD EPYC systems arch, ia64: Make NUMA select SMP sched, perf: MAINTAINERS update, add submaintainers and reviewers sched/fair: Use rq_lock/unlock in online_fair_sched_group cpufreq: schedutil: fix equation in comment sched: Rework pick_next_task() slow-path sched: Allow put_prev_task() to drop rq->lock sched/fair: Expose newidle_balance() sched: Add task_struct pointer to sched_class::set_curr_task sched: Rework CPU hotplug task selection sched/{rt,deadline}: Fix set_next_task vs pick_next_task sched: Fix kerneldoc comment for ia64_set_curr_task ... |
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Matt Fleming
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a55c7454a8 |
sched/topology: Improve load balancing on AMD EPYC systems
SD_BALANCE_{FORK,EXEC} and SD_WAKE_AFFINE are stripped in sd_init()
for any sched domains with a NUMA distance greater than 2 hops
(RECLAIM_DISTANCE). The idea being that it's expensive to balance
across domains that far apart.
However, as is rather unfortunately explained in:
commit
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David Rientjes
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cd96103838 |
mm, page_alloc: move_freepages should not examine struct page of reserved memory
After commit |
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Christoph Hellwig
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fdc029b19d |
memremap: remove the dev field in struct dev_pagemap
The dev field in struct dev_pagemap is only used to print dev_name in two places, which are at best nice to have. Just remove the field and thus the name in those two messages. Link: https://lore.kernel.org/r/20190818090557.17853-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Bharata B Rao <bharata@linux.ibm.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
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Dan Williams
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ba72b4c8cf |
mm/sparsemem: support sub-section hotplug
The libnvdimm sub-system has suffered a series of hacks and broken workarounds for the memory-hotplug implementation's awkward section-aligned (128MB) granularity. For example the following backtrace is emitted when attempting arch_add_memory() with physical address ranges that intersect 'System RAM' (RAM) with 'Persistent Memory' (PMEM) within a given section: # cat /proc/iomem | grep -A1 -B1 Persistent\ Memory 100000000-1ffffffff : System RAM 200000000-303ffffff : Persistent Memory (legacy) 304000000-43fffffff : System RAM 440000000-23ffffffff : Persistent Memory 2400000000-43bfffffff : Persistent Memory 2400000000-43bfffffff : namespace2.0 WARNING: CPU: 38 PID: 928 at arch/x86/mm/init_64.c:850 add_pages+0x5c/0x60 [..] RIP: 0010:add_pages+0x5c/0x60 [..] Call Trace: devm_memremap_pages+0x460/0x6e0 pmem_attach_disk+0x29e/0x680 [nd_pmem] ? nd_dax_probe+0xfc/0x120 [libnvdimm] nvdimm_bus_probe+0x66/0x160 [libnvdimm] It was discovered that the problem goes beyond RAM vs PMEM collisions as some platform produce PMEM vs PMEM collisions within a given section. The libnvdimm workaround for that case revealed that the libnvdimm section-alignment-padding implementation has been broken for a long while. A fix for that long-standing breakage introduces as many problems as it solves as it would require a backward-incompatible change to the namespace metadata interpretation. Instead of that dubious route [1], address the root problem in the memory-hotplug implementation. Note that EEXIST is no longer treated as success as that is how sparse_add_section() reports subsection collisions, it was also obviated by recent changes to perform the request_region() for 'System RAM' before arch_add_memory() in the add_memory() sequence. [1] https://lore.kernel.org/r/155000671719.348031.2347363160141119237.stgit@dwillia2-desk3.amr.corp.intel.com [osalvador@suse.de: fix deactivate_section for early sections] Link: http://lkml.kernel.org/r/20190715081549.32577-2-osalvador@suse.de Link: http://lkml.kernel.org/r/156092354368.979959.6232443923440952359.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Oscar Salvador <osalvador@suse.de> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64] Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Wei Yang <richardw.yang@linux.intel.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Dan Williams
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46d945aeab |
mm: kill is_dev_zone() helper
Given there are no more usages of is_dev_zone() outside of 'ifdef CONFIG_ZONE_DEVICE' protection, kill off the compilation helper. Link: http://lkml.kernel.org/r/156092353211.979959.1489004866360828964.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Wei Yang <richardw.yang@linux.intel.com> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64] Cc: Michal Hocko <mhocko@suse.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Dan Williams
|
f46edbd1b1 |
mm/sparsemem: add helpers track active portions of a section at boot
Prepare for hot{plug,remove} of sub-ranges of a section by tracking a sub-section active bitmask, each bit representing a PMD_SIZE span of the architecture's memory hotplug section size. The implications of a partially populated section is that pfn_valid() needs to go beyond a valid_section() check and either determine that the section is an "early section", or read the sub-section active ranges from the bitmask. The expectation is that the bitmask (subsection_map) fits in the same cacheline as the valid_section() / early_section() data, so the incremental performance overhead to pfn_valid() should be negligible. The rationale for using early_section() to short-ciruit the subsection_map check is that there are legacy code paths that use pfn_valid() at section granularity before validating the pfn against pgdat data. So, the early_section() check allows those traditional assumptions to persist while also permitting subsection_map to tell the truth for purposes of populating the unused portions of early sections with PMEM and other ZONE_DEVICE mappings. Link: http://lkml.kernel.org/r/156092350874.979959.18185938451405518285.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Qian Cai <cai@lca.pw> Tested-by: Jane Chu <jane.chu@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64] Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Wei Yang <richardw.yang@linux.intel.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Dan Williams
|
f1eca35a0d |
mm/sparsemem: introduce struct mem_section_usage
Patch series "mm: Sub-section memory hotplug support", v10. The memory hotplug section is an arbitrary / convenient unit for memory hotplug. 'Section-size' units have bled into the user interface ('memblock' sysfs) and can not be changed without breaking existing userspace. The section-size constraint, while mostly benign for typical memory hotplug, has and continues to wreak havoc with 'device-memory' use cases, persistent memory (pmem) in particular. Recall that pmem uses devm_memremap_pages(), and subsequently arch_add_memory(), to allocate a 'struct page' memmap for pmem. However, it does not use the 'bottom half' of memory hotplug, i.e. never marks pmem pages online and never exposes the userspace memblock interface for pmem. This leaves an opening to redress the section-size constraint. To date, the libnvdimm subsystem has attempted to inject padding to satisfy the internal constraints of arch_add_memory(). Beyond complicating the code, leading to bugs [2], wasting memory, and limiting configuration flexibility, the padding hack is broken when the platform changes this physical memory alignment of pmem from one boot to the next. Device failure (intermittent or permanent) and physical reconfiguration are events that can cause the platform firmware to change the physical placement of pmem on a subsequent boot, and device failure is an everyday event in a data-center. It turns out that sections are only a hard requirement of the user-facing interface for memory hotplug and with a bit more infrastructure sub-section arch_add_memory() support can be added for kernel internal usages like devm_memremap_pages(). Here is an analysis of the current design assumptions in the current code and how they are addressed in the new implementation: Current design assumptions: - Sections that describe boot memory (early sections) are never unplugged / removed. - pfn_valid(), in the CONFIG_SPARSEMEM_VMEMMAP=y, case devolves to a valid_section() check - __add_pages() and helper routines assume all operations occur in PAGES_PER_SECTION units. - The memblock sysfs interface only comprehends full sections New design assumptions: - Sections are instrumented with a sub-section bitmask to track (on x86) individual 2MB sub-divisions of a 128MB section. - Partially populated early sections can be extended with additional sub-sections, and those sub-sections can be removed with arch_remove_memory(). With this in place we no longer lose usable memory capacity to padding. - pfn_valid() is updated to look deeper than valid_section() to also check the active-sub-section mask. This indication is in the same cacheline as the valid_section() so the performance impact is expected to be negligible. So far the lkp robot has not reported any regressions. - Outside of the core vmemmap population routines which are replaced, other helper routines like shrink_{zone,pgdat}_span() are updated to handle the smaller granularity. Core memory hotplug routines that deal with online memory are not touched. - The existing memblock sysfs user api guarantees / assumptions are not touched since this capability is limited to !online !memblock-sysfs-accessible sections. Meanwhile the issue reports continue to roll in from users that do not understand when and how the 128MB constraint will bite them. The current implementation relied on being able to support at least one misaligned namespace, but that immediately falls over on any moderately complex namespace creation attempt. Beyond the initial problem of 'System RAM' colliding with pmem, and the unsolvable problem of physical alignment changes, Linux is now being exposed to platforms that collide pmem ranges with other pmem ranges by default [3]. In short, devm_memremap_pages() has pushed the venerable section-size constraint past the breaking point, and the simplicity of section-aligned arch_add_memory() is no longer tenable. These patches are exposed to the kbuild robot on a subsection-v10 branch [4], and a preview of the unit test for this functionality is available on the 'subsection-pending' branch of ndctl [5]. [2]: https://lore.kernel.org/r/155000671719.348031.2347363160141119237.stgit@dwillia2-desk3.amr.corp.intel.com [3]: https://github.com/pmem/ndctl/issues/76 [4]: https://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm.git/log/?h=subsection-v10 [5]: https://github.com/pmem/ndctl/commit/7c59b4867e1c This patch (of 13): Towards enabling memory hotplug to track partial population of a section, introduce 'struct mem_section_usage'. A pointer to a 'struct mem_section_usage' instance replaces the existing pointer to a 'pageblock_flags' bitmap. Effectively it adds one more 'unsigned long' beyond the 'pageblock_flags' (usemap) allocation to house a new 'subsection_map' bitmap. The new bitmap enables the memory hot{plug,remove} implementation to act on incremental sub-divisions of a section. SUBSECTION_SHIFT is defined as global constant instead of per-architecture value like SECTION_SIZE_BITS in order to allow cross-arch compatibility of subsection users. Specifically a common subsection size allows for the possibility that persistent memory namespace configurations be made compatible across architectures. The primary motivation for this functionality is to support platforms that mix "System RAM" and "Persistent Memory" within a single section, or multiple PMEM ranges with different mapping lifetimes within a single section. The section restriction for hotplug has caused an ongoing saga of hacks and bugs for devm_memremap_pages() users. Beyond the fixups to teach existing paths how to retrieve the 'usemap' from a section, and updates to usemap allocation path, there are no expected behavior changes. Link: http://lkml.kernel.org/r/156092349845.979959.73333291612799019.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Wei Yang <richardw.yang@linux.intel.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64] Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Qian Cai <cai@lca.pw> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Yafang Shao
|
e5ca8071fe |
mm/vmscan.c: add a new member reclaim_state in struct shrink_control
Patch series "mm/vmscan: calculate reclaimed slab in all reclaim paths". This patchset is to fix the issues in doing shrink slab. There're six different reclaim paths by now, - kswapd reclaim path - node reclaim path - hibernate preallocate memory reclaim path - direct reclaim path - memcg reclaim path - memcg softlimit reclaim path The slab caches reclaimed in these paths are only calculated in the above three paths. The issues are detailed explained in patch #2. We should calculate the reclaimed slab caches in every reclaim path. In order to do it, the struct reclaim_state is placed into the struct shrink_control. In node reclaim path, there'is another issue about shrinking slab, which is adressed in "mm/vmscan: shrink slab in node reclaim" (https://lore.kernel.org/linux-mm/1559874946-22960-1-git-send-email-laoar.shao@gmail.com/). This patch (of 2): The struct reclaim_state is used to record how many slab caches are reclaimed in one reclaim path. The struct shrink_control is used to control one reclaim path. So we'd better put reclaim_state into shrink_control. [laoar.shao@gmail.com: remove reclaim_state assignment from __perform_reclaim()] Link: http://lkml.kernel.org/r/1561381582-13697-1-git-send-email-laoar.shao@gmail.com Link: http://lkml.kernel.org/r/1561112086-6169-2-git-send-email-laoar.shao@gmail.com Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.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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Linus Torvalds
|
fec88ab0af |
HMM patches for 5.3
Improvements and bug fixes for the hmm interface in the kernel: - Improve clarity, locking and APIs related to the 'hmm mirror' feature merged last cycle. In linux-next we now see AMDGPU and nouveau to be using this API. - Remove old or transitional hmm APIs. These are hold overs from the past with no users, or APIs that existed only to manage cross tree conflicts. There are still a few more of these cleanups that didn't make the merge window cut off. - Improve some core mm APIs: * export alloc_pages_vma() for driver use * refactor into devm_request_free_mem_region() to manage DEVICE_PRIVATE resource reservations * refactor duplicative driver code into the core dev_pagemap struct - Remove hmm wrappers of improved core mm APIs, instead have drivers use the simplified API directly - Remove DEVICE_PUBLIC - Simplify the kconfig flow for the hmm users and core code -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfB7FMLh+8QxL+6i3OG33FX4gmxoFAl0k1zkACgkQOG33FX4g mxrO+w//QF/yI/9Hh30RWEBq8W107cODkDlaT0Z/7cVEXfGetZzIUpqzxnJofRfQ xTw1XmYkc9WpJe/mTTuFZFewNQwWuMM6X0Xi25fV438/Y64EclevlcJTeD49TIH1 CIMsz8bX7CnCEq5sz+UypLg9LPnaD9L/JLyuSbyjqjms/o+yzqa7ji7p/DSINuhZ Qva9OZL1ZSEDJfNGi8uGpYBqryHoBAonIL12R9sCF5pbJEnHfWrH7C06q7AWOAjQ 4vjN/p3F4L9l/v2IQ26Kn/S0AhmN7n3GT//0K66e2gJPfXa8fxRKGuFn/Kd79EGL YPASn5iu3cM23up1XkbMNtzacL8yiIeTOcMdqw26OaOClojy/9OJduv5AChe6qL/ VUQIAn1zvPsJTyC5U7mhmkrGuTpP6ivHpxtcaUp+Ovvi1cyK40nLCmSNvLnbN5ES bxbb0SjE4uupDG5qU6Yct/hFp6uVMSxMqXZOb9Xy8ZBkbMsJyVOLj71G1/rVIfPU hO1AChX5CRG1eJoMo6oBIpiwmSvcOaPp3dqIOQZvwMOqrO869LR8qv7RXyh/g9gi FAEKnwLl4GK3YtEO4Kt/1YI5DXYjSFUbfgAs0SPsRKS6hK2+RgRk2M/B/5dAX0/d lgOf9WPODPwiSXBYLtJB8qHVDX0DIY8faOyTx6BYIKClUtgbBI8= =wKvp -----END PGP SIGNATURE----- Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma Pull HMM updates from Jason Gunthorpe: "Improvements and bug fixes for the hmm interface in the kernel: - Improve clarity, locking and APIs related to the 'hmm mirror' feature merged last cycle. In linux-next we now see AMDGPU and nouveau to be using this API. - Remove old or transitional hmm APIs. These are hold overs from the past with no users, or APIs that existed only to manage cross tree conflicts. There are still a few more of these cleanups that didn't make the merge window cut off. - Improve some core mm APIs: - export alloc_pages_vma() for driver use - refactor into devm_request_free_mem_region() to manage DEVICE_PRIVATE resource reservations - refactor duplicative driver code into the core dev_pagemap struct - Remove hmm wrappers of improved core mm APIs, instead have drivers use the simplified API directly - Remove DEVICE_PUBLIC - Simplify the kconfig flow for the hmm users and core code" * tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (42 commits) mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR mm: remove the HMM config option mm: sort out the DEVICE_PRIVATE Kconfig mess mm: simplify ZONE_DEVICE page private data mm: remove hmm_devmem_add mm: remove hmm_vma_alloc_locked_page nouveau: use devm_memremap_pages directly nouveau: use alloc_page_vma directly PCI/P2PDMA: use the dev_pagemap internal refcount device-dax: use the dev_pagemap internal refcount memremap: provide an optional internal refcount in struct dev_pagemap memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag memremap: remove the data field in struct dev_pagemap memremap: add a migrate_to_ram method to struct dev_pagemap_ops memremap: lift the devmap_enable manipulation into devm_memremap_pages memremap: pass a struct dev_pagemap to ->kill and ->cleanup memremap: move dev_pagemap callbacks into a separate structure memremap: validate the pagemap type passed to devm_memremap_pages mm: factor out a devm_request_free_mem_region helper mm: export alloc_pages_vma ... |
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Alexander Potapenko
|
6471384af2 |
mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options
Patch series "add init_on_alloc/init_on_free boot options", v10. Provide init_on_alloc and init_on_free boot options. These are aimed at preventing possible information leaks and making the control-flow bugs that depend on uninitialized values more deterministic. Enabling either of the options guarantees that the memory returned by the page allocator and SL[AU]B is initialized with zeroes. SLOB allocator isn't supported at the moment, as its emulation of kmem caches complicates handling of SLAB_TYPESAFE_BY_RCU caches correctly. Enabling init_on_free also guarantees that pages and heap objects are initialized right after they're freed, so it won't be possible to access stale data by using a dangling pointer. As suggested by Michal Hocko, right now we don't let the heap users to disable initialization for certain allocations. There's not enough evidence that doing so can speed up real-life cases, and introducing ways to opt-out may result in things going out of control. This patch (of 2): The new options are needed to prevent possible information leaks and make control-flow bugs that depend on uninitialized values more deterministic. This is expected to be on-by-default on Android and Chrome OS. And it gives the opportunity for anyone else to use it under distros too via the boot args. (The init_on_free feature is regularly requested by folks where memory forensics is included in their threat models.) init_on_alloc=1 makes the kernel initialize newly allocated pages and heap objects with zeroes. Initialization is done at allocation time at the places where checks for __GFP_ZERO are performed. init_on_free=1 makes the kernel initialize freed pages and heap objects with zeroes upon their deletion. This helps to ensure sensitive data doesn't leak via use-after-free accesses. Both init_on_alloc=1 and init_on_free=1 guarantee that the allocator returns zeroed memory. The two exceptions are slab caches with constructors and SLAB_TYPESAFE_BY_RCU flag. Those are never zero-initialized to preserve their semantics. Both init_on_alloc and init_on_free default to zero, but those defaults can be overridden with CONFIG_INIT_ON_ALLOC_DEFAULT_ON and CONFIG_INIT_ON_FREE_DEFAULT_ON. If either SLUB poisoning or page poisoning is enabled, those options take precedence over init_on_alloc and init_on_free: initialization is only applied to unpoisoned allocations. Slowdown for the new features compared to init_on_free=0, init_on_alloc=0: hackbench, init_on_free=1: +7.62% sys time (st.err 0.74%) hackbench, init_on_alloc=1: +7.75% sys time (st.err 2.14%) Linux build with -j12, init_on_free=1: +8.38% wall time (st.err 0.39%) Linux build with -j12, init_on_free=1: +24.42% sys time (st.err 0.52%) Linux build with -j12, init_on_alloc=1: -0.13% wall time (st.err 0.42%) Linux build with -j12, init_on_alloc=1: +0.57% sys time (st.err 0.40%) The slowdown for init_on_free=0, init_on_alloc=0 compared to the baseline is within the standard error. The new features are also going to pave the way for hardware memory tagging (e.g. arm64's MTE), which will require both on_alloc and on_free hooks to set the tags for heap objects. With MTE, tagging will have the same cost as memory initialization. Although init_on_free is rather costly, there are paranoid use-cases where in-memory data lifetime is desired to be minimized. There are various arguments for/against the realism of the associated threat models, but given that we'll need the infrastructure for MTE anyway, and there are people who want wipe-on-free behavior no matter what the performance cost, it seems reasonable to include it in this series. [glider@google.com: v8] Link: http://lkml.kernel.org/r/20190626121943.131390-2-glider@google.com [glider@google.com: v9] Link: http://lkml.kernel.org/r/20190627130316.254309-2-glider@google.com [glider@google.com: v10] Link: http://lkml.kernel.org/r/20190628093131.199499-2-glider@google.com Link: http://lkml.kernel.org/r/20190617151050.92663-2-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Michal Hocko <mhocko@suse.cz> [page and dmapool parts Acked-by: James Morris <jamorris@linux.microsoft.com>] Cc: Christoph Lameter <cl@linux.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Sandeep Patil <sspatil@android.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Jann Horn <jannh@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Nicholas Piggin
|
e03a5125ec |
mm/large system hash: clear hashdist when only one node with memory is booted
CONFIG_NUMA on 64-bit CPUs currently enables hashdist unconditionally even when booting on single node machines. This causes the large system hashes to be allocated with vmalloc, and mapped with small pages. This change clears hashdist if only one node has come up with memory. This results in the important large inode and dentry hashes using memblock allocations. All others are within 4MB size up to about 128GB of RAM, which allows them to be allocated from the linear map on most non-NUMA images. Other big hashes like futex and TCP should eventually be moved over to the same style of allocation as those vfs caches that use HASH_EARLY if !hashdist, so they don't exceed MAX_ORDER on very large non-NUMA images. This brings dTLB misses for linux kernel tree `git diff` from ~45,000 to ~8,000 on a Kaby Lake KVM guest with 8MB dentry hash and mitigations=off (performance is in the noise, under 1% difference, page tables are likely to be well cached for this workload). Link: http://lkml.kernel.org/r/20190605144814.29319-2-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Nicholas Piggin
|
ec11408a16 |
mm/large system hash: use vmalloc for size > MAX_ORDER when !hashdist
The kernel currently clamps large system hashes to MAX_ORDER when hashdist is not set, which is rather arbitrary. vmalloc space is limited on 32-bit machines, but this shouldn't result in much more used because of small physical memory limiting system hash sizes. Include "vmalloc" or "linear" in the kernel log message. Link: http://lkml.kernel.org/r/20190605144814.29319-1-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
|
3972f6bb1c |
mm, debug_pagealloc: use a page type instead of page_ext flag
When debug_pagealloc is enabled, we currently allocate the page_ext array to mark guard pages with the PAGE_EXT_DEBUG_GUARD flag. Now that we have the page_type field in struct page, we can use that instead, as guard pages are neither PageSlab nor mapped to userspace. This reduces memory overhead when debug_pagealloc is enabled and there are no other features requiring the page_ext array. Link: http://lkml.kernel.org/r/20190603143451.27353-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> 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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Vlastimil Babka
|
4462b32c92 |
mm, page_alloc: more extensive free page checking with debug_pagealloc
The page allocator checks struct pages for expected state (mapcount, flags etc) as pages are being allocated (check_new_page()) and freed (free_pages_check()) to provide some defense against errors in page allocator users. Prior commits |
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Vlastimil Babka
|
96a2b03f28 |
mm, debug_pagelloc: use static keys to enable debugging
Patch series "debug_pagealloc improvements".
I have been recently debugging some pcplist corruptions, where it would be
useful to perform struct page checks immediately as pages are allocated
from and freed to pcplists, which is now only possible by rebuilding the
kernel with CONFIG_DEBUG_VM (details in Patch 2 changelog).
To make this kind of debugging simpler in future on a distro kernel, I
have improved CONFIG_DEBUG_PAGEALLOC so that it has even smaller overhead
when not enabled at boot time (Patch 1) and also when enabled (Patch 3),
and extended it to perform the struct page checks more often when enabled
(Patch 2). Now it can be configured in when building a distro kernel
without extra overhead, and debugging page use after free or double free
can be enabled simply by rebooting with debug_pagealloc=on.
This patch (of 3):
CONFIG_DEBUG_PAGEALLOC has been redesigned by
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Denis Efremov
|
98ef2046f2 |
mm: remove the exporting of totalram_pages
Previously totalram_pages was the global variable. Currently,
totalram_pages is the static inline function from the include/linux/mm.h
However, the function is also marked as EXPORT_SYMBOL, which is at best an
odd combination. Because there is no point for the static inline function
from a public header to be exported, this commit removes the
EXPORT_SYMBOL() marking. It will be still possible to use the function in
modules because all the symbols it depends on are exported.
Link: http://lkml.kernel.org/r/20190710141031.15642-1-efremov@linux.com
Fixes:
|
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Juergen Gross
|
b9705d8778 |
mm/page_alloc.c: fix regression with deferred struct page init
Commit |
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Christoph Hellwig
|
8a164fef9c |
mm: simplify ZONE_DEVICE page private data
Remove the clumsy hmm_devmem_page_{get,set}_drvdata helpers, and instead just access the page directly. Also make the page data a void pointer, and thus much easier to use. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
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Christoph Hellwig
|
514caf23a7 |
memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag
Add a flags field to struct dev_pagemap to replace the altmap_valid boolean to be a little more extensible. Also add a pgmap_altmap() helper to find the optional altmap and clean up the code using the altmap using it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> |
||
Thomas Gleixner
|
457c899653 |
treewide: Add SPDX license identifier for missed files
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Dan Williams
|
97500a4a54 |
mm: maintain randomization of page free lists
When freeing a page with an order >= shuffle_page_order randomly select the front or back of the list for insertion. While the mm tries to defragment physical pages into huge pages this can tend to make the page allocator more predictable over time. Inject the front-back randomness to preserve the initial randomness established by shuffle_free_memory() when the kernel was booted. The overhead of this manipulation is constrained by only being applied for MAX_ORDER sized pages by default. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/154899812788.3165233.9066631950746578517.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Robert Elliott <elliott@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Dan Williams
|
b03641af68 |
mm: move buddy list manipulations into helpers
In preparation for runtime randomization of the zone lists, take all (well, most of) the list_*() functions in the buddy allocator and put them in helper functions. Provide a common control point for injecting additional behavior when freeing pages. [dan.j.williams@intel.com: fix buddy list helpers] Link: http://lkml.kernel.org/r/155033679702.1773410.13041474192173212653.stgit@dwillia2-desk3.amr.corp.intel.com [vbabka@suse.cz: remove del_page_from_free_area() migratetype parameter] Link: http://lkml.kernel.org/r/4672701b-6775-6efd-0797-b6242591419e@suse.cz Link: http://lkml.kernel.org/r/154899812264.3165233.5219320056406926223.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Keith Busch <keith.busch@intel.com> Cc: Robert Elliott <elliott@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Dan Williams
|
e900a918b0 |
mm: shuffle initial free memory to improve memory-side-cache utilization
Patch series "mm: Randomize free memory", v10.
This patch (of 3):
Randomization of the page allocator improves the average utilization of
a direct-mapped memory-side-cache. Memory side caching is a platform
capability that Linux has been previously exposed to in HPC
(high-performance computing) environments on specialty platforms. In
that instance it was a smaller pool of high-bandwidth-memory relative to
higher-capacity / lower-bandwidth DRAM. Now, this capability is going
to be found on general purpose server platforms where DRAM is a cache in
front of higher latency persistent memory [1].
Robert offered an explanation of the state of the art of Linux
interactions with memory-side-caches [2], and I copy it here:
It's been a problem in the HPC space:
http://www.nersc.gov/research-and-development/knl-cache-mode-performance-coe/
A kernel module called zonesort is available to try to help:
https://software.intel.com/en-us/articles/xeon-phi-software
and this abandoned patch series proposed that for the kernel:
https://lkml.kernel.org/r/20170823100205.17311-1-lukasz.daniluk@intel.com
Dan's patch series doesn't attempt to ensure buffers won't conflict, but
also reduces the chance that the buffers will. This will make performance
more consistent, albeit slower than "optimal" (which is near impossible
to attain in a general-purpose kernel). That's better than forcing
users to deploy remedies like:
"To eliminate this gradual degradation, we have added a Stream
measurement to the Node Health Check that follows each job;
nodes are rebooted whenever their measured memory bandwidth
falls below 300 GB/s."
A replacement for zonesort was merged upstream in commit
|
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Baruch Siach
|
136ac591f0 |
mm: update references to page _refcount
Commit |
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Mike Rapoport
|
350e88bad4 |
mm: memblock: make keeping memblock memory opt-in rather than opt-out
Most architectures do not need the memblock memory after the page allocator is initialized, but only few enable ARCH_DISCARD_MEMBLOCK in the arch Kconfig. Replacing ARCH_DISCARD_MEMBLOCK with ARCH_KEEP_MEMBLOCK and inverting the logic makes it clear which architectures actually use memblock after system initialization and skips the necessity to add ARCH_DISCARD_MEMBLOCK to the architectures that are still missing that option. Link: http://lkml.kernel.org/r/1556102150-32517-1-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: James Hogan <jhogan@kernel.org> Cc: Ley Foon Tan <lftan@altera.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Yafang Shao
|
1c52e6d068 |
mm/page_alloc.c: remove unnecessary parameter in rmqueue_pcplist
Because rmqueue_pcplist() is only called when order is 0, we don't need to use order as a parameter. Link: http://lkml.kernel.org/r/1555591709-11744-1-git-send-email-laoar.shao@gmail.com Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Pankaj Gupta <pagupta@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
|
5557c766ab |
mm, memory_hotplug: cleanup memory offline path
check_pages_isolated_cb currently accounts the whole pfn range as being offlined if test_pages_isolated suceeds on the range. This is based on the assumption that all pages in the range are freed which is currently the case in most cases but it won't be with later changes, as pages marked as vmemmap won't be isolated. Move the offlined pages counting to offline_isolated_pages_cb and rely on __offline_isolated_pages to return the correct value. check_pages_isolated_cb will still do it's primary job and check the pfn range. While we are at it remove check_pages_isolated and offline_isolated_pages and use directly walk_system_ram_range as do in online_pages. Link: http://lkml.kernel.org/r/20190408082633.2864-2-osalvador@suse.de Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Oscar Salvador <osalvador@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alexander Duyck
|
0e56acae4b |
mm: initialize MAX_ORDER_NR_PAGES at a time instead of doing larger sections
Add yet another iterator, for_each_free_mem_range_in_zone_from, and then use it to support initializing and freeing pages in groups no larger than MAX_ORDER_NR_PAGES. By doing this we can greatly improve the cache locality of the pages while we do several loops over them in the init and freeing process. We are able to tighten the loops further as a result of the "from" iterator as we can perform the initial checks for first_init_pfn in our first call to the iterator, and continue without the need for those checks via the "from" iterator. I have added this functionality in the function called deferred_init_mem_pfn_range_in_zone that primes the iterator and causes us to exit if we encounter any failure. On my x86_64 test system with 384GB of memory per node I saw a reduction in initialization time from 1.85s to 1.38s as a result of this patch. Link: http://lkml.kernel.org/r/20190405221231.12227.85836.stgit@localhost.localdomain Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: <yi.z.zhang@linux.intel.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: David S. Miller <davem@davemloft.net> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alexander Duyck
|
837566e7e0 |
mm: implement new zone specific memblock iterator
Introduce a new iterator for_each_free_mem_pfn_range_in_zone. This iterator will take care of making sure a given memory range provided is in fact contained within a zone. It takes are of all the bounds checking we were doing in deferred_grow_zone, and deferred_init_memmap. In addition it should help to speed up the search a bit by iterating until the end of a range is greater than the start of the zone pfn range, and will exit completely if the start is beyond the end of the zone. Link: http://lkml.kernel.org/r/20190405221225.12227.22573.stgit@localhost.localdomain Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@kernel.org> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <yi.z.zhang@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alexander Duyck
|
56ec43d8b0 |
mm: drop meminit_pfn_in_nid as it is redundant
As best as I can tell the meminit_pfn_in_nid call is completely redundant. The deferred memory initialization is already making use of for_each_free_mem_range which in turn will call into __next_mem_range which will only return a memory range if it matches the node ID provided assuming it is not NUMA_NO_NODE. I am operating on the assumption that there are no zones or pgdata_t structures that have a NUMA node of NUMA_NO_NODE associated with them. If that is the case then __next_mem_range will never return a memory range that doesn't match the zone's node ID and as such the check is redundant. So one piece I would like to verify on this is if this works for ia64. Technically it was using a different approach to get the node ID, but it seems to have the node ID also encoded into the memblock. So I am assuming this is okay, but would like to get confirmation on that. On my x86_64 test system with 384GB of memory per node I saw a reduction in initialization time from 2.80s to 1.85s as a result of this patch. Link: http://lkml.kernel.org/r/20190405221219.12227.93957.stgit@localhost.localdomain Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@kernel.org> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <yi.z.zhang@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Linxu Fang
|
299c83dce9 |
mem-hotplug: fix node spanned pages when we have a node with only ZONE_MOVABLE
|
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Alexandre Ghiti
|
4eb0716e86 |
hugetlb: allow to free gigantic pages regardless of the configuration
On systems without CONTIG_ALLOC activated but that support gigantic pages, boottime reserved gigantic pages can not be freed at all. This patch simply enables the possibility to hand back those pages to memory allocator. Link: http://lkml.kernel.org/r/20190327063626.18421-5-alex@ghiti.fr Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Acked-by: David S. Miller <davem@davemloft.net> [sparc] Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Andy Lutomirsky <luto@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Alexandre Ghiti
|
8df995f6bd |
mm: simplify MEMORY_ISOLATION && COMPACTION || CMA into CONTIG_ALLOC
This condition allows to define alloc_contig_range, so simplify it into a more accurate naming. Link: http://lkml.kernel.org/r/20190327063626.18421-4-alex@ghiti.fr Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andy Lutomirsky <luto@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
|
63931eb975 |
mm, page_alloc: disallow __GFP_COMP in alloc_pages_exact()
alloc_pages_exact*() allocates a page of sufficient order and then splits it to return only the number of pages requested. That makes it incompatible with __GFP_COMP, because compound pages cannot be split. As shown by [1] things may silently work until the requested size (possibly depending on user) stops being power of two. Then for CONFIG_DEBUG_VM, BUG_ON() triggers in split_page(). Without CONFIG_DEBUG_VM, consequences are unclear. There are several options here, none of them great: 1) Don't do the splitting when __GFP_COMP is passed, and return the whole compound page. However if caller then returns it via free_pages_exact(), that will be unexpected and the freeing actions there will be wrong. 2) Warn and remove __GFP_COMP from the flags. But the caller may have really wanted it, so things may break later somewhere. 3) Warn and return NULL. However NULL may be unexpected, especially for small sizes. This patch picks option 2, because as Michal Hocko put it: "callers wanted it" is much less probable than "caller is simply confused and more gfp flags is surely better than fewer". [1] https://lore.kernel.org/lkml/20181126002805.GI18977@shao2-debian/T/#u Link: http://lkml.kernel.org/r/0c6393eb-b28d-4607-c386-862a71f09de6@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Takashi Iwai <tiwai@suse.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Rick Edgecombe
|
d633269286 |
mm/hibernation: Make hibernation handle unmapped pages
Make hibernate handle unmapped pages on the direct map when CONFIG_ARCH_HAS_SET_ALIAS=y is set. These functions allow for setting pages to invalid configurations, so now hibernate should check if the pages have valid mappings and handle if they are unmapped when doing a hibernate save operation. Previously this checking was already done when CONFIG_DEBUG_PAGEALLOC=y was configured. It does not appear to have a big hibernating performance impact. The speed of the saving operation before this change was measured as 819.02 MB/s, and after was measured at 813.32 MB/s. Before: [ 4.670938] PM: Wrote 171996 kbytes in 0.21 seconds (819.02 MB/s) After: [ 4.504714] PM: Wrote 178932 kbytes in 0.22 seconds (813.32 MB/s) Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-16-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Andrey Ryabinin
|
8118b82eb7 |
mm/page_alloc.c: fix never set ALLOC_NOFRAGMENT flag
Commit |
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Andrey Ryabinin
|
8139ad043d |
mm/page_alloc.c: avoid potential NULL pointer dereference
ac.preferred_zoneref->zone passed to alloc_flags_nofragment() can be NULL.
'zone' pointer unconditionally derefernced in alloc_flags_nofragment().
Bail out on NULL zone to avoid potential crash. Currently we don't see
any crashes only because alloc_flags_nofragment() has another bug which
allows compiler to optimize away all accesses to 'zone'.
Link: http://lkml.kernel.org/r/20190423120806.3503-1-aryabinin@virtuozzo.com
Fixes:
|
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Mel Gorman
|
ee8ab0eeb4 |
mm, page_alloc: always use a captured page regardless of compaction result
During the development of commit |
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Mel Gorman
|
24512228b7 |
mm: do not boost watermarks to avoid fragmentation for the DISCONTIG memory model
Mikulas Patocka reported that commit |
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Qian Cai
|
1a9f219157 |
mm/hotplug: treat CMA pages as unmovable
has_unmovable_pages() is used by allocating CMA and gigantic pages as well as the memory hotplug. The later doesn't know how to offline CMA pool properly now, but if an unused (free) CMA page is encountered, then has_unmovable_pages() happily considers it as a free memory and propagates this up the call chain. Memory offlining code then frees the page without a proper CMA tear down which leads to an accounting issues. Moreover if the same memory range is onlined again then the memory never gets back to the CMA pool. State after memory offline: # grep cma /proc/vmstat nr_free_cma 205824 # cat /sys/kernel/debug/cma/cma-kvm_cma/count 209920 Also, kmemleak still think those memory address are reserved below but have already been used by the buddy allocator after onlining. This patch fixes the situation by treating CMA pageblocks as unmovable except when has_unmovable_pages() is called as part of CMA allocation. Offlined Pages 4096 kmemleak: Cannot insert 0xc000201f7d040008 into the object search tree (overlaps existing) Call Trace: dump_stack+0xb0/0xf4 (unreliable) create_object+0x344/0x380 __kmalloc_node+0x3ec/0x860 kvmalloc_node+0x58/0x110 seq_read+0x41c/0x620 __vfs_read+0x3c/0x70 vfs_read+0xbc/0x1a0 ksys_read+0x7c/0x140 system_call+0x5c/0x70 kmemleak: Kernel memory leak detector disabled kmemleak: Object 0xc000201cc8000000 (size 13757317120): kmemleak: comm "swapper/0", pid 0, jiffies 4294937297 kmemleak: min_count = -1 kmemleak: count = 0 kmemleak: flags = 0x5 kmemleak: checksum = 0 kmemleak: backtrace: cma_declare_contiguous+0x2a4/0x3b0 kvm_cma_reserve+0x11c/0x134 setup_arch+0x300/0x3f8 start_kernel+0x9c/0x6e8 start_here_common+0x1c/0x4b0 kmemleak: Automatic memory scanning thread ended [cai@lca.pw: use is_migrate_cma_page() and update commit log] Link: http://lkml.kernel.org/r/20190416170510.20048-1-cai@lca.pw Link: http://lkml.kernel.org/r/20190413002623.8967-1-cai@lca.pw Signed-off-by: Qian Cai <cai@lca.pw> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |