- 06 Jul, 2017 40 commits
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Vlastimil Babka authored
I would like to stress that this patchset aims to fix issues and cleanup the code *within the existing documented semantics*, i.e. patch 1 ignores mempolicy restrictions if the set of allowed nodes has no intersection with set of nodes allowed by cpuset. I believe discussing potential changes of the semantics can be better done once we have a baseline with no known bugs of the current semantics. I've recently summarized the cpuset/mempolicy issues in a LSF/MM proposal [1] and the discussion itself [2]. I've been trying to rewrite the handling as proposed, with the idea that changing semantics to make all mempolicies static wrt cpuset updates (and discarding the relative and default modes) can be tried on top, as there's a high risk of being rejected/reverted because somebody might still care about the removed modes. However I haven't yet figured out how to properly: 1) make mempolicies swappable instead of rebinding in place. I thought mbind() already works that way and uses refcounting to avoid use-after-free of the old policy by a parallel allocation, but turns out true refcounting is only done for shared (shmem) mempolicies, and the actual protection for mbind() comes from mmap_sem. Extending the refcounting means more overhead in allocator hot path. Also swapping whole mempolicies means that we have to allocate the new ones, which can fail, and reverting of the partially done work also means allocating (note that mbind() doesn't care and will just leave part of the range updated and part not updated when returning -ENOMEM...). 2) make cpuset's task->mems_allowed also swappable (after converting it from nodemask to zonelist, which is the easy part) for mostly the same reasons. The good news is that while trying to do the above, I've at least figured out how to hopefully close the remaining premature OOM's, and do a buch of cleanups on top, removing quite some of the code that was also supposed to prevent the cpuset update races, but doesn't work anymore nowadays. This should fix the most pressing concerns with this topic and give us a better baseline before either proceeding with the original proposal, or pushing a change of semantics that removes the problem 1) above. I'd be then fine with trying to change the semantic first and rewrite later. Patchset has been tested with the LTP cpuset01 stress test. [1] https://lkml.kernel.org/r/4c44a589-5fd8-08d0-892c-e893bb525b71@suse.cz [2] https://lwn.net/Articles/717797/ [3] https://marc.info/?l=linux-mm&m=149191957922828&w=2 This patch (of 6): Commit e47483bc ("mm, page_alloc: fix premature OOM when racing with cpuset mems update") has fixed known recent regressions found by LTP's cpuset01 testcase. I have however found that by modifying the testcase to use per-vma mempolicies via bind(2) instead of per-task mempolicies via set_mempolicy(2), the premature OOM still happens and the issue is much older. The root of the problem is that the cpuset's mems_allowed and mempolicy's nodemask can temporarily have no intersection, thus get_page_from_freelist() cannot find any usable zone. The current semantic for empty intersection is to ignore mempolicy's nodemask and honour cpuset restrictions. This is checked in node_zonelist(), but the racy update can happen after we already passed the check. Such races should be protected by the seqlock task->mems_allowed_seq, but it doesn't work here, because 1) mpol_rebind_mm() does not happen under seqlock for write, and doing so would lead to deadlock, as it takes mmap_sem for write, while the allocation can have mmap_sem for read when it's taking the seqlock for read. And 2) the seqlock cookie of callers of node_zonelist() (alloc_pages_vma() and alloc_pages_current()) is different than the one of __alloc_pages_slowpath(), so there's still a potential race window. This patch fixes the issue by having __alloc_pages_slowpath() check for empty intersection of cpuset and ac->nodemask before OOM or allocation failure. If it's indeed empty, the nodemask is ignored and allocation retried, which mimics node_zonelist(). This works fine, because almost all callers of __alloc_pages_nodemask are obtaining the nodemask via node_zonelist(). The only exception is new_node_page() from hotplug, where the potential violation of nodemask isn't an issue, as there's already a fallback allocation attempt without any nodemask. If there's a future caller that needs to have its specific nodemask honoured over task's cpuset restrictions, we'll have to e.g. add a gfp flag for that. Link: http://lkml.kernel.org/r/20170517081140.30654-2-vbabka@suse.czSigned-off-by:
Vlastimil Babka <vbabka@suse.cz> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Punit Agrawal authored
Using set_pte_at() does not do the right thing when putting down HWPOISON swap entries for hugepages on architectures that support contiguous ptes. Fix this problem by using set_huge_swap_pte_at() which was introduced to fix exactly this problem. Link: http://lkml.kernel.org/r/20170522133604.11392-7-punit.agrawal@arm.comSigned-off-by:
Punit Agrawal <punit.agrawal@arm.com> Acked-by:
Steve Capper <steve.capper@arm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by:
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Punit Agrawal authored
set_huge_pte_at(), an architecture callback to populate hugepage ptes, does not provide the range of virtual memory that is targeted. This leads to ambiguity when dealing with swap entries on architectures that support hugepages consisting of contiguous ptes. Fix the problem by introducing an overridable helper that is called when populating the page tables with swap entries. The size of the targeted region is provided to the helper to help determine the number of entries to be updated. Provide a default implementation that maintains the current behaviour. [punit.agrawal@arm.com: v4] Link: http://lkml.kernel.org/r/20170524115409.31309-8-punit.agrawal@arm.com [punit.agrawal@arm.com: add an empty definition for set_huge_swap_pte_at()] Link: http://lkml.kernel.org/r/20170525171331.31469-1-punit.agrawal@arm.com Link: http://lkml.kernel.org/r/20170522133604.11392-6-punit.agrawal@arm.comSigned-off-by:
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Punit Agrawal authored
When unmapping a hugepage range, huge_pte_clear() is used to clear the page table entries that are marked as not present. huge_pte_clear() internally just ends up calling pte_clear() which does not correctly deal with hugepages consisting of contiguous page table entries. Add a size argument to address this issue and allow architectures to override huge_pte_clear() by wrapping it in a #ifndef block. Update s390 implementation with the size parameter as well. Note that the change only affects huge_pte_clear() - the other generic hugetlb functions don't need any change. Link: http://lkml.kernel.org/r/20170522162555.4313-1-punit.agrawal@arm.comSigned-off-by:
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Punit Agrawal authored
A poisoned or migrated hugepage is stored as a swap entry in the page tables. On architectures that support hugepages consisting of contiguous page table entries (such as on arm64) this leads to ambiguity in determining the page table entry to return in huge_pte_offset() when a poisoned entry is encountered. Let's remove the ambiguity by adding a size parameter to convey additional information about the requested address. Also fixup the definition/usage of huge_pte_offset() throughout the tree. Link: http://lkml.kernel.org/r/20170522133604.11392-4-punit.agrawal@arm.comSigned-off-by:
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Punit Agrawal authored
When speculatively taking references to a hugepage using page_cache_add_speculative() in gup_huge_pmd(), it is assumed that the page returned by pmd_page() is the head page. Although normally true, this assumption doesn't hold when the hugepage comprises of successive page table entries such as when using contiguous bit on arm64 at PTE or PMD levels. This can be addressed by ensuring that the page passed to page_cache_add_speculative() is the real head or by de-referencing the head page within the function. We take the first approach to keep the usage pattern aligned with page_cache_get_speculative() where users already pass the appropriate page, i.e., the de-referenced head. Apply the same logic to fix gup_huge_[pud|pgd]() as well. [punit.agrawal@arm.com: fix arm64 ltp failure] Link: http://lkml.kernel.org/r/20170619170145.25577-5-punit.agrawal@arm.com Link: http://lkml.kernel.org/r/20170522133604.11392-3-punit.agrawal@arm.comSigned-off-by:
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Will Deacon authored
When operating on hugepages with DEBUG_VM enabled, the GUP code checks the compound head for each tail page prior to calling page_cache_add_speculative. This is broken, because on the fast-GUP path (where we don't hold any page table locks) we can be racing with a concurrent invocation of split_huge_page_to_list. split_huge_page_to_list deals with this race by using page_ref_freeze to freeze the page and force concurrent GUPs to fail whilst the component pages are modified. This modification includes clearing the compound_head field for the tail pages, so checking this prior to a successful call to page_cache_add_speculative can lead to false positives: In fact, page_cache_add_speculative *already* has this check once the page refcount has been successfully updated, so we can simply remove the broken calls to VM_BUG_ON_PAGE. Link: http://lkml.kernel.org/r/20170522133604.11392-2-punit.agrawal@arm.comSigned-off-by:
Will Deacon <will.deacon@arm.com> Signed-off-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by:
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Steve Capper authored
We don't need to call huge_ptep_offset as our accessors are already supplied with the pte_t *. This patch removes those spurious calls. [punit.agrawal@arm.com: resolve rebase conflicts due to patch re-ordering] Link: http://lkml.kernel.org/r/20170524115409.31309-3-punit.agrawal@arm.comSigned-off-by:
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Steve Capper authored
Patch series "Support for contiguous pte hugepages", v4. This patchset updates the hugetlb code to fix issues arising from contiguous pte hugepages (such as on arm64). Compared to v3, This version addresses a build failure on arm64 by including two cleanup patches. Other than the arm64 cleanups, the rest are generic code changes. The remaining arm64 support based on these patches will be posted separately. The patches are based on v4.12-rc2. Previous related postings can be found at [0], [1], [2], and [3]. The patches fall into three categories - * Patch 1-2 - arm64 cleanups required to greatly simplify changing huge_pte_offset() prototype in Patch 5. Catalin, Will - are you happy for these patches to go via mm? * Patches 3-4 address issues with gup * Patches 5-8 relate to passing a size argument to hugepage helpers to disambiguate the size of the referred page. These changes are required to enable arch code to properly handle swap entries for contiguous pte hugepages. The changes to huge_pte_offset() (patch 5) touch multiple architectures but I've managed to minimise these changes for the other affected functions - huge_pte_clear() and set_huge_pte_at(). These patches gate the enabling of contiguous hugepages support on arm64 which has been requested for systems using !4k page granule. The ARM64 architecture supports two flavours of hugepages - * Block mappings at the pud/pmd level These are regular hugepages where a pmd or a pud page table entry points to a block of memory. Depending on the PAGE_SIZE in use the following size of block mappings are supported - PMD PUD --- --- 4K: 2M 1G 16K: 32M 64K: 512M For certain applications/usecases such as HPC and large enterprise workloads, folks are using 64k page size but the minimum hugepage size of 512MB isn't very practical. To overcome this ... * Using the Contiguous bit The architecture provides a contiguous bit in the translation table entry which acts as a hint to the mmu to indicate that it is one of a contiguous set of entries that can be cached in a single TLB entry. We use the contiguous bit in Linux to increase the mapping size at the pmd and pte (last) level. The number of supported contiguous entries varies by page size and level of the page table. Using the contiguous bit allows additional hugepage sizes - CONT PTE PMD CONT PMD PUD -------- --- -------- --- 4K: 64K 2M 32M 1G 16K: 2M 32M 1G 64K: 2M 512M 16G Of these, 64K with 4K and 2M with 64K pages have been explicitly requested by a few different users. Entries with the contiguous bit set are required to be modified all together - which makes things like memory poisoning and migration impossible to do correctly without knowing the size of hugepage being dealt with - the reason for adding size parameter to a few of the hugepage helpers in this series. This patch (of 8): As we regularly check for contiguous pte's in the huge accessors, remove this extra check from find_num_contig. [punit.agrawal@arm.com: resolve rebase conflicts due to patch re-ordering] Link: http://lkml.kernel.org/r/20170524115409.31309-2-punit.agrawal@arm.comSigned-off-by: -
Naoya Horiguchi authored
pte_offset_map_lock() finds and takes ptl, and returns pte. But some callers return without unlocking the ptl when pte == NULL, which seems weird. Git history said that !pte check in change_pte_range() was introduced in commit 1ad9f620 ("mm: numa: recheck for transhuge pages under lock during protection changes") and still remains after commit 175ad4f1 ("mm: mprotect: use pmd_trans_unstable instead of taking the pmd_lock") which partially reverts 1ad9f620. So I think that it's just dead code. Many other caller of pte_offset_map_lock() never check NULL return, so let's do likewise. Link: http://lkml.kernel.org/r/1495089737-1292-1-git-send-email-n-horiguchi@ah.jp.nec.comSigned-off-by:
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by:
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Matthias Kaehlcke authored
The functions are not used in some configurations. Adding the attribute fixes the following warnings when building with clang: mm/page_alloc.c:409:19: error: function 'bad_range' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration] mm/page_alloc.c:1106:30: error: unused function 'meminit_pfn_in_nid' [-Werror,-Wunused-function] Link: http://lkml.kernel.org/r/20170518182030.165633-1-mka@chromium.orgSigned-off-by:Matthias Kaehlcke <mka@chromium.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by:
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Aneesh Kumar K.V authored
POWER9 supports hugepages of size 2M and 1G in radix MMU mode. This patch enables the usage of 1G page size for hugetlbfs. This also update the helper such we can do 1G page allocation at runtime. We still don't enable 1G page size on DD1 version. This is to avoid doing workaround mentioned in commit 6d3a0379 ("powerpc/mm: Add radix__tlb_flush_pte_p9_dd1()"). Link: http://lkml.kernel.org/r/1494995292-4443-2-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by:
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Aneesh Kumar K.V authored
This moves the #ifdef in C code to a Kconfig dependency. Also we move the gigantic_page_supported() function to be arch specific. This allows architectures to conditionally enable runtime allocation of gigantic huge page. Architectures like ppc64 supports different gigantic huge page size (16G and 1G) based on the translation mode selected. This provides an opportunity for ppc64 to enable runtime allocation only w.r.t 1G hugepage. No functional change in this patch. Link: http://lkml.kernel.org/r/1494995292-4443-1-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
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Pavel Tatashin authored
Allow hash tables to scale with memory but at slower pace, when HASH_ADAPT is provided every time memory quadruples the sizes of hash tables will only double instead of quadrupling as well. This algorithm starts working only when memory size reaches a certain point, currently set to 64G. This is example of dentry hash table size, before and after four various memory configurations: MEMORY SCALE HASH_SIZE old new old new 8G 13 13 8M 8M 16G 13 13 16M 16M 32G 13 13 32M 32M 64G 13 13 64M 64M 128G 13 14 128M 64M 256G 13 14 256M 128M 512G 13 15 512M 128M 1024G 13 15 1024M 256M 2048G 13 16 2048M 256M 4096G 13 16 4096M 512M 8192G 13 17 8192M 512M 16384G 13 17 16384M 1024M 32768G 13 18 32768M 1024M 65536G 13 18 65536M 2048M The effect of this change on runtime is undetectable as filesystem growth is not proportional to machine memory size as is currently assumed. The change effects only large memory machine. Additional tuning might be needed, but that can be done by the clients of the kmem_cache_create interface, not the generic cache allocator itself. The adaptive hashing is disabled on 32 bit systems to avoid confusion of whether base should be different for smaller systems, and to avoid overflows. [mhocko@suse.com: drop HASH_ADAPT] Link: http://lkml.kernel.org/r/20170509094607.GG6481@dhcp22.suse.cz [pasha.tatashin@oracle.com: UL -> ULL fix] Link: http://lkml.kernel.org/r/1495300013-653283-2-git-send-email-pasha.tatashin@oracle.com [pasha.tatashin@oracle.com: disable adaptive hash on 32 bit systems] Link: http://lkml.kernel.org/r/1495469329-755807-2-git-send-email-pasha.tatashin@oracle.com Link: http://lkml.kernel.org/r/1488432825-92126-5-git-send-email-pasha.tatashin@oracle.comSigned-off-by:Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by:
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Pavel Tatashin authored
Update dcache, inode, pid, mountpoint, and mount hash tables to use HASH_ZERO, and remove initialization after allocations. In case of places where HASH_EARLY was used such as in __pv_init_lock_hash the zeroed hash table was already assumed, because memblock zeroes the memory. CPU: SPARC M6, Memory: 7T Before fix: Dentry cache hash table entries: 1073741824 Inode-cache hash table entries: 536870912 Mount-cache hash table entries: 16777216 Mountpoint-cache hash table entries: 16777216 ftrace: allocating 20414 entries in 40 pages Total time: 11.798s After fix: Dentry cache hash table entries: 1073741824 Inode-cache hash table entries: 536870912 Mount-cache hash table entries: 16777216 Mountpoint-cache hash table entries: 16777216 ftrace: allocating 20414 entries in 40 pages Total time: 3.198s CPU: Intel Xeon E5-2630, Memory: 2.2T: Before fix: Dentry cache hash table entries: 536870912 Inode-cache hash table entries: 268435456 Mount-cache hash table entries: 8388608 Mountpoint-cache hash table entries: 8388608 CPU: Physical Processor ID: 0 Total time: 3.245s After fix: Dentry cache hash table entries: 536870912 Inode-cache hash table entries: 268435456 Mount-cache hash table entries: 8388608 Mountpoint-cache hash table entries: 8388608 CPU: Physical Processor ID: 0 Total time: 3.244s Link: http://lkml.kernel.org/r/1488432825-92126-4-git-send-email-pasha.tatashin@oracle.comSigned-off-by:
Babu Moger <babu.moger@oracle.com> Cc: David Miller <davem@davemloft.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Pavel Tatashin authored
Add a new flag HASH_ZERO which when provided grantees that the hash table that is returned by alloc_large_system_hash() is zeroed. In most cases that is what is needed by the caller. Use page level allocator's __GFP_ZERO flags to zero the memory. It is using memset() which is efficient method to zero memory and is optimized for most platforms. Link: http://lkml.kernel.org/r/1488432825-92126-3-git-send-email-pasha.tatashin@oracle.comSigned-off-by:
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Aneesh Kumar K.V authored
Link: http://lkml.kernel.org/r/1494926612-23928-10-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
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Aneesh Kumar K.V authored
With generic code now handling hugetlb entries at pgd level and also supporting hugepage directory format, we can now remove the powerpc sepcific follow_huge_addr implementation. Link: http://lkml.kernel.org/r/1494926612-23928-9-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
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Aneesh Kumar K.V authored
Link: http://lkml.kernel.org/r/1494926612-23928-8-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
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Aneesh Kumar K.V authored
Architectures like ppc64 supports hugepage size that is not mapped to any of of the page table levels. Instead they add an alternate page table entry format called hugepage directory (hugepd). hugepd indicates that the page table entry maps to a set of hugetlb pages. Add support for this in generic follow_page_mask code. We already support this format in the generic gup code. The default implementation prints warning and returns NULL. We will add ppc64 support in later patches Link: http://lkml.kernel.org/r/1494926612-23928-7-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
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Aneesh Kumar K.V authored
This enable to use the hugepd_t type early. No functional change in this patch. Link: http://lkml.kernel.org/r/1494926612-23928-6-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
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Anshuman Khandual authored
ppc64 supports pgd hugetlb entries. Add code to handle hugetlb pgd entries to follow_page_mask so that ppc64 can switch to it to handle hugetlbe entries. Link: http://lkml.kernel.org/r/1494926612-23928-5-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by:
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Aneesh Kumar K.V authored
We will be using this later from the ppc64 code. Change the return type to bool. Link: http://lkml.kernel.org/r/1494926612-23928-4-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
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Aneesh Kumar K.V authored
Makes code reading easy. No functional changes in this patch. In a followup patch, we will be updating the follow_page_mask to handle hugetlb hugepd format so that archs like ppc64 can switch to the generic version. This split helps in doing that nicely. Link: http://lkml.kernel.org/r/1494926612-23928-3-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
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Aneesh Kumar K.V authored
Patch series "HugeTLB migration support for PPC64", v2. This patch (of 9): The right interface to use to set a hugetlb pte entry is set_huge_pte_at. Use that instead of set_pte_at. Link: http://lkml.kernel.org/r/1494926612-23928-2-git-send-email-aneesh.kumar@linux.vnet.ibm.comSigned-off-by:
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Anshuman Khandual authored
Though migrating gigantic HugeTLB pages does not sound much like real world use case, they can be affected by memory errors. Hence migration at the PGD level HugeTLB pages should be supported just to enable soft and hard offline use cases. While allocating the new gigantic HugeTLB page, it should not matter whether new page comes from the same node or not. There would be very few gigantic pages on the system afterall, we should not be bothered about node locality when trying to save a big page from crashing. This change renames dequeu_huge_page_node() function as dequeue_huge _page_node_exact() preserving it's original functionality. Now the new dequeue_huge_page_node() function scans through all available online nodes to allocate a huge page for the NUMA_NO_NODE case and just falls back calling dequeu_huge_page_node_exact() for all other cases. [arnd@arndb.de: make hstate_is_gigantic() inline] Link: http://lkml.kernel.org/r/20170522124748.3911296-1-arnd@arndb.de Link: http://lkml.kernel.org/r/20170516100509.20122-1-khandual@linux.vnet.ibm.comSigned-off-by:
Arnd Bergmann <arnd@arndb.de> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by:
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Mike Rapoport authored
Calculation of start end end in __wake_userfault function are not used and can be removed. Link: http://lkml.kernel.org/r/1494930917-3134-1-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by:
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Mike Rapoport authored
Commit dd0db88d ("userfaultfd: non-cooperative: rollback userfaultfd_exit") removed userfaultfd callback from exit() which makes the include of <linux/userfaultfd_k.h> unnecessary. Link: http://lkml.kernel.org/r/1494930907-3060-1-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Michal Hocko authored
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.orgSigned-off-by:
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Michal Hocko authored
Tobias has reported following section mismatches introduced by "mm, memory_hotplug: do not associate hotadded memory to zones until online". WARNING: mm/built-in.o(.text+0x5a1c2): Section mismatch in reference from the function move_pfn_range_to_zone() to the function .meminit.text:memmap_init_zone() The function move_pfn_range_to_zone() references the function __meminit memmap_init_zone(). This is often because move_pfn_range_to_zone lacks a __meminit annotation or the annotation of memmap_init_zone is wrong. WARNING: mm/built-in.o(.text+0x5a25b): Section mismatch in reference from the function move_pfn_range_to_zone() to the function .meminit.text:init_currently_empty_zone() The function move_pfn_range_to_zone() references the function __meminit init_currently_empty_zone(). This is often because move_pfn_range_to_zone lacks a __meminit annotation or the annotation of init_currently_empty_zone is wrong. WARNING: vmlinux.o(.text+0x188aa2): Section mismatch in reference from the function move_pfn_range_to_zone() to the function .meminit.text:memmap_init_zone() The function move_pfn_range_to_zone() references the function __meminit memmap_init_zone(). This is often because move_pfn_range_to_zone lacks a __meminit annotation or the annotation of memmap_init_zone is wrong. WARNING: vmlinux.o(.text+0x188b3b): Section mismatch in reference from the function move_pfn_range_to_zone() to the function .meminit.text:init_currently_empty_zone() The function move_pfn_range_to_zone() references the function __meminit init_currently_empty_zone(). This is often because move_pfn_range_to_zone lacks a __meminit annotation or the annotation of init_currently_empty_zone is wrong. Both memmap_init_zone and init_currently_empty_zone are marked __meminit but move_pfn_range_to_zone is used outside of __meminit sections (e.g. devm_memremap_pages) so we have to hide it from the checker by __ref annotation. Link: http://lkml.kernel.org/r/20170515085827.16474-14-mhocko@kernel.orgSigned-off-by:
Tobias Regnery <tobias.regnery@gmail.com> 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: Toshi Kani <toshi.kani@hpe.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by:
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Michal Hocko authored
arch_add_memory gets for_device argument which then controls whether we want to create memblocks for created memory sections. Simplify the logic by telling whether we want memblocks directly rather than going through pointless negation. This also makes the api easier to understand because it is clear what we want rather than nothing telling for_device which can mean anything. This shouldn't introduce any functional change. Link: http://lkml.kernel.org/r/20170515085827.16474-13-mhocko@kernel.orgSigned-off-by:
Dan Williams <dan.j.williams@intel.com> Acked-by:
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Michal Hocko authored
Heiko Carstens has noticed that he can generate overlapping zones for ZONE_DMA and ZONE_NORMAL: DMA [mem 0x0000000000000000-0x000000007fffffff] Normal [mem 0x0000000080000000-0x000000017fffffff] $ cat /sys/devices/system/memory/block_size_bytes 10000000 $ cat /sys/devices/system/memory/memory5/valid_zones DMA $ echo 0 > /sys/devices/system/memory/memory5/online $ cat /sys/devices/system/memory/memory5/valid_zones Normal $ echo 1 > /sys/devices/system/memory/memory5/online Normal $ cat /proc/zoneinfo Node 0, zone DMA spanned 524288 <----- present 458752 managed 455078 start_pfn: 0 <----- Node 0, zone Normal spanned 720896 present 589824 managed 571648 start_pfn: 327680 <----- The reason is that we assume that the default zone for kernel onlining is ZONE_NORMAL. This was a simplification introduced by the memory hotplug rework and it is easily fixable by checking the range overlap in the zone order and considering the first matching zone as the default one. If there is no such zone then assume ZONE_NORMAL as we have been doing so far. Fixes: "mm, memory_hotplug: do not associate hotadded memory to zones until online" Link: http://lkml.kernel.org/r/20170601083746.4924-3-mhocko@kernel.orgSigned-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by:
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Michal Hocko authored
Heiko Carstens has noticed that the MMOP_ONLINE_KEEP is broken currently $ grep . memory3?/valid_zones memory34/valid_zones:Normal Movable memory35/valid_zones:Normal Movable memory36/valid_zones:Normal Movable memory37/valid_zones:Normal Movable $ echo online_movable > memory34/state $ grep . memory3?/valid_zones memory34/valid_zones:Movable memory35/valid_zones:Movable memory36/valid_zones:Movable memory37/valid_zones:Movable $ echo online > memory36/state $ grep . memory3?/valid_zones memory34/valid_zones:Movable memory36/valid_zones:Normal memory37/valid_zones:Movable so we have effectively punched a hole into the movable zone. The problem is that move_pfn_range() check for MMOP_ONLINE_KEEP is wrong. It only checks whether the given range is already part of the movable zone which is not the case here as only memory34 is in the zone. Fix this by using allow_online_pfn_range(..., MMOP_ONLINE_KERNEL) if that is false then we can be sure that movable onlining is the right thing to do. Fixes: "mm, memory_hotplug: do not associate hotadded memory to zones until online" Link: http://lkml.kernel.org/r/20170601083746.4924-2-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
The current memory hotplug implementation relies on having all the struct pages associate with a zone/node during the physical hotplug phase (arch_add_memory->__add_pages->__add_section->__add_zone). In the vast majority of cases this means that they are added to ZONE_NORMAL. This has been so since 9d99aaa3 ("[PATCH] x86_64: Support memory hotadd without sparsemem") and it wasn't a big deal back then because movable onlining didn't exist yet. Much later memory hotplug wanted to (ab)use ZONE_MOVABLE for movable onlining 511c2aba ("mm, memory-hotplug: dynamic configure movable memory and portion memory") and then things got more complicated. Rather than reconsidering the zone association which was no longer needed (because the memory hotplug already depended on SPARSEMEM) a convoluted semantic of zone shifting has been developed. Only the currently last memblock or the one adjacent to the zone_movable can be onlined movable. This essentially means that the online type changes as the new memblocks are added. Let's simulate memory hot online manually $ echo 0x100000000 > /sys/devices/system/memory/probe $ grep . /sys/devices/system/memory/memory32/valid_zones Normal Movable $ echo $((0x100000000+(128<<20))) > /sys/devices/system/memory/probe $ grep . /sys/devices/system/memory/memory3?/valid_zones /sys/devices/system/memory/memory32/valid_zones:Normal /sys/devices/system/memory/memory33/valid_zones:Normal Movable $ echo $((0x100000000+2*(128<<20))) > /sys/devices/system/memory/probe $ grep . /sys/devices/system/memory/memory3?/valid_zones /sys/devices/system/memory/memory32/valid_zones:Normal /sys/devices/system/memory/memory33/valid_zones:Normal /sys/devices/system/memory/memory34/valid_zones:Normal Movable $ echo online_movable > /sys/devices/system/memory/memory34/state $ grep . /sys/devices/system/memory/memory3?/valid_zones /sys/devices/system/memory/memory32/valid_zones:Normal /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Movable Normal This is an awkward semantic because an udev event is sent as soon as the block is onlined and an udev handler might want to online it based on some policy (e.g. association with a node) but it will inherently race with new blocks showing up. This patch changes the physical online phase to not associate pages with any zone at all. All the pages are just marked reserved and wait for the onlining phase to be associated with the zone as per the online request. There are only two requirements - existing ZONE_NORMAL and ZONE_MOVABLE cannot overlap - ZONE_NORMAL precedes ZONE_MOVABLE in physical addresses the latter one is not an inherent requirement and can be changed in the future. It preserves the current behavior and made the code slightly simpler. This is subject to change in future. This means that the same physical online steps as above will lead to the following state: Normal Movable /sys/devices/system/memory/memory32/valid_zones:Normal Movable /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory32/valid_zones:Normal Movable /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Normal Movable /sys/devices/system/memory/memory32/valid_zones:Normal Movable /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Movable Implementation: The current move_pfn_range is reimplemented to check the above requirements (allow_online_pfn_range) and then updates the respective zone (move_pfn_range_to_zone), the pgdat and links all the pages in the pfn range with the zone/node. __add_pages is updated to not require the zone and only initializes sections in the range. This allowed to simplify the arch_add_memory code (s390 could get rid of quite some of code). devm_memremap_pages is the only user of arch_add_memory which relies on the zone association because it only hooks into the memory hotplug only half way. It uses it to associate the new memory with ZONE_DEVICE but doesn't allow it to be {on,off}lined via sysfs. This means that this particular code path has to call move_pfn_range_to_zone explicitly. The original zone shifting code is kept in place and will be removed in the follow up patch for an easier review. Please note that this patch also changes the original behavior when offlining a memory block adjacent to another zone (Normal vs. Movable) used to allow to change its movable type. This will be handled later. [richard.weiyang@gmail.com: simplify zone_intersects()] Link: http://lkml.kernel.org/r/20170616092335.5177-1-richard.weiyang@gmail.com [richard.weiyang@gmail.com: remove duplicate call for set_page_links] Link: http://lkml.kernel.org/r/20170616092335.5177-2-richard.weiyang@gmail.com [akpm@linux-foundation.org: remove unused local `i'] Link: http://lkml.kernel.org/r/20170515085827.16474-12-mhocko@kernel.orgSigned-off-by:
Wei Yang <richard.weiyang@gmail.com> Tested-by:
Reza Arbab <arbab@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # For s390 bits Acked-by:
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Michal Hocko authored
pagetypeinfo_showblockcount_print skips over invalid pfns but it would report pages which are offline because those have a valid pfn. Their migrate type is misleading at best. Now that we have pfn_to_online_page() we can use it instead of pfn_valid() and fix this. [mhocko@suse.com: fix build] Link: http://lkml.kernel.org/r/20170519072225.GA13041@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20170515085827.16474-11-mhocko@kernel.orgSigned-off-by:
Joonsoo Kim <js1304@gmail.com> Acked-by:
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Michal Hocko authored
__first_valid_page skips over invalid pfns in the range but it might still stumble over offline pages. At least start_isolate_page_range will mark those set_migratetype_isolate. This doesn't represent any immediate AFAICS because alloc_contig_range will fail to isolate those pages but it relies on not fully initialized page which will become a problem later when we stop associating offline pages to zones. Use pfn_to_online_page to handle this. This is more a preparatory patch than a fix. Link: http://lkml.kernel.org/r/20170515085827.16474-10-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
__reset_isolation_suitable walks the whole zone pfn range and it tries to jump over holes by checking the zone for each page. It might still stumble over offline pages, though. Skip those by checking pfn_to_online_page() Link: http://lkml.kernel.org/r/20170515085827.16474-9-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
__pageblock_pfn_to_page has two users currently, set_zone_contiguous which checks whether the given zone contains holes and pageblock_pfn_to_page which then carefully returns a first valid page from the given pfn range for the given zone. This doesn't handle zones which are not fully populated though. Memory pageblocks can be offlined or might not have been onlined yet. In such a case the zone should be considered to have holes otherwise pfn walkers can touch and play with offline pages. Current callers of pageblock_pfn_to_page in compaction seem to work properly right now because they only isolate PageBuddy (isolate_freepages_block) or PageLRU resp. __PageMovable (isolate_migratepages_block) which will be always false for these pages. It would be safer to skip these pages altogether, though. In order to do this patch adds a new memory section state (SECTION_IS_ONLINE) which is set in memory_present (during boot time) or in online_pages_range during the memory hotplug. Similarly offline_mem_sections clears the bit and it is called when the memory range is offlined. pfn_to_online_page helper is then added which check the mem section and only returns a page if it is onlined already. Use the new helper in __pageblock_pfn_to_page and skip the whole page block in such a case. [mhocko@suse.com: check valid section number in pfn_to_online_page (Vlastimil), mark sections online after all struct pages are initialized in online_pages_range (Vlastimil)] Link: http://lkml.kernel.org/r/20170518164210.GD18333@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20170515085827.16474-8-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
is_pageblock_removable_nolock() relies on having zone association to examine all the page blocks to check whether they are movable or free. This is just wasting of cycles when the memblock is offline. Later patch in the series will also change the time when the page is associated with a zone so we let's bail out early if the memblock is offline. Link: http://lkml.kernel.org/r/20170515085827.16474-7-mhocko@kernel.orgSigned-off-by:
Igor Mammedov <imammedo@redhat.com> Acked-by:
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Michal Hocko authored
Memory hotplug (add_memory_resource) has to reinitialize node infrastructure if the node is offline (one which went through the complete add_memory(); remove_memory() cycle). That involves node registration to the kobj infrastructure (register_node), the proper association with cpus (register_cpu_under_node) and finally creation of node<->memblock symlinks (link_mem_sections). The last part requires to know node_start_pfn and node_spanned_pages which we currently have but a leter patch will postpone this initialization to the onlining phase which happens later. In fact we do not need to rely on the early pgdat initialization even now because the currently hot added pfn range is currently known. Split register_one_node into core which does all the common work for the boot time NUMA initialization and the hotplug (__register_one_node). register_one_node keeps the full initialization while hotplug calls __register_one_node and manually calls link_mem_sections for the proper range. This shouldn't introduce any functional change. Link: http://lkml.kernel.org/r/20170515085827.16474-6-mhocko@kernel.orgSigned-off-by:
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