- 06 Jul, 2017 40 commits
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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:
Punit Agrawal <punit.agrawal@arm.com> Acked-by:
Steve Capper <steve.capper@arm.com> Acked-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:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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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:
Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-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:
Michal Hocko <mhocko@suse.com> Acked-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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Michal Hocko authored
Device memory hotplug hooks into regular memory hotplug only half way. It needs memory sections to track struct pages but there is no need/desire to associate those sections with memory blocks and export them to the userspace via sysfs because they cannot be onlined anyway. This is currently expressed by for_device argument to arch_add_memory which then makes sure to associate the given memory range with ZONE_DEVICE. register_new_memory then relies on is_zone_device_section to distinguish special memory hotplug from the regular one. While this works now, later patches in this series want to move __add_zone outside of arch_add_memory path so we have to come up with something else. Add want_memblock down the __add_pages path and use it to control whether the section->memblock association should be done. arch_add_memory then just trivially want memblock for everything but for_device hotplug. remove_memory_section doesn't need is_zone_device_section either. We can simply skip all the memblock specific cleanup if there is no memblock for the given section. This shouldn't introduce any functional change. Link: http://lkml.kernel.org/r/20170515085827.16474-5-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
Commit c04fc586 ("mm: show node to memory section relationship with symlinks in sysfs") has added means to export memblock<->node association into the sysfs. It has also introduced get_nid_for_pfn which is a rather confusing counterpart of pfn_to_nid which checks also whether the pfn page is already initialized (page_initialized). This is done by checking page::lru != NULL which doesn't make any sense at all. Nothing in this path really relies on the lru list being used or initialized. Just remove it because this will become a problem with later patches. Thanks to Reza Arbab for testing which revealed this to be a problem (http://lkml.kernel.org/r/20170403202337.GA12482@dhcp22.suse.cz) Link: http://lkml.kernel.org/r/20170515085827.16474-4-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
The primary purpose of this helper is to query the node state so use the node id directly. This is a preparatory patch for later changes. This shouldn't introduce any functional change Link: http://lkml.kernel.org/r/20170515085827.16474-3-mhocko@kernel.orgSigned-off-by:
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Acked-by:
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Michal Hocko authored
Patch series "mm: make movable onlining suck less", v4. Movable onlining is a real hack with many downsides - mainly reintroduction of lowmem/highmem issues we used to have on 32b systems - but it is the only way to make the memory hotremove more reliable which is something that people are asking for. The current semantic of memory movable onlinening is really cumbersome, however. The main reason for this is that the udev driven approach is basically unusable because udev races with the memory probing while only the last memory block or the one adjacent to the existing zone_movable are allowed to be onlined movable. In short the criterion for the successful online_movable changes under udev's feet. A reliable udev approach would require a 2 phase approach where the first successful movable online would have to check all the previous blocks and online them in descending order. This is hard to be considered sane. This patchset aims at making the onlining semantic more usable. First of all it allows to online memory movable as long as it doesn't clash with the existing ZONE_NORMAL. That means that ZONE_NORMAL and ZONE_MOVABLE cannot overlap. Currently I preserve the original ordering semantic so the zone always precedes the movable zone but I have plans to remove this restriction in future because it is not really necessary. First 3 patches are cleanups which should be ready to be merged right away (unless I have missed something subtle of course). Patch 4 deals with ZONE_DEVICE dependencies down the __add_pages path. Patch 5 deals with implicit assumptions of register_one_node on pgdat initialization. Patches 6-10 deal with offline holes in the zone for pfn walkers. I hope I got all of them right but people familiar with compaction should double check this. Patch 11 is the core of the change. In order to make it easier to review I have tried it to be as minimalistic as possible and the large code removal is moved to patch 14. Patch 12 is a trivial follow up cleanup. Patch 13 fixes sparse warnings and finally patch 14 removes the unused code. I have tested the patches in kvm: # qemu-system-x86_64 -enable-kvm -monitor pty -m 2G,slots=4,maxmem=4G -numa node,mem=1G -numa node,mem=1G ... and then probed the additional memory by (qemu) object_add memory-backend-ram,id=mem1,size=1G (qemu) device_add pc-dimm,id=dimm1,memdev=mem1 Then I have used this simple script to probe the memory block by hand # cat probe_memblock.sh #!/bin/sh BLOCK_NR=$1 # echo $((0x100000000+$BLOCK_NR*(128<<20))) > /sys/devices/system/memory/probe # for i in $(seq 10); do sh probe_memblock.sh $i; done # grep . /sys/devices/system/memory/memory3?/valid_zones 2>/dev/null /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Normal Movable /sys/devices/system/memory/memory35/valid_zones:Normal Movable /sys/devices/system/memory/memory36/valid_zones:Normal Movable /sys/devices/system/memory/memory37/valid_zones:Normal Movable /sys/devices/system/memory/memory38/valid_zones:Normal Movable /sys/devices/system/memory/memory39/valid_zones:Normal Movable The main difference to the original implementation is that all new memblocks can be both online_kernel and online_movable initially because there is no clash obviously. For the comparison the original implementation would have /sys/devices/system/memory/memory33/valid_zones:Normal /sys/devices/system/memory/memory34/valid_zones:Normal /sys/devices/system/memory/memory35/valid_zones:Normal /sys/devices/system/memory/memory36/valid_zones:Normal /sys/devices/system/memory/memory37/valid_zones:Normal /sys/devices/system/memory/memory38/valid_zones:Normal /sys/devices/system/memory/memory39/valid_zones:Normal Movable Now # echo online_movable > /sys/devices/system/memory/memory34/state # grep . /sys/devices/system/memory/memory3?/valid_zones 2>/dev/null /sys/devices/system/memory/memory33/valid_zones:Normal Movable /sys/devices/system/memory/memory34/valid_zones:Movable /sys/devices/system/memory/memory35/valid_zones:Movable /sys/devices/system/memory/memory36/valid_zones:Movable /sys/devices/system/memory/memory37/valid_zones:Movable /sys/devices/system/memory/memory38/valid_zones:Movable /sys/devices/system/memory/memory39/valid_zones:Movable Block 33 can still be online both kernel and movable while all the remaining can be only movable. /proc/zonelist says Node 0, zone Normal pages free 0 min 0 low 0 high 0 spanned 0 present 0 -- Node 0, zone Movable pages free 32753 min 85 low 117 high 149 spanned 32768 present 32768 A new memblock at a lower address will result in a new memblock (32) which will still allow both Normal and Movable. # sh probe_memblock.sh 0 # grep . /sys/devices/system/memory/memory3[2-5]/valid_zones 2>/dev/null /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 /sys/devices/system/memory/memory35/valid_zones:Movable and online_kernel will convert it to the zone normal properly while 33 can be still onlined both ways. # echo online_kernel > /sys/devices/system/memory/memory32/state # grep . /sys/devices/system/memory/memory3[2-5]/valid_zones 2>/dev/null /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 /sys/devices/system/memory/memory35/valid_zones:Movable /proc/zoneinfo will now tell Node 0, zone Normal pages free 65441 min 165 low 230 high 295 spanned 65536 present 65536 -- Node 0, zone Movable pages free 32740 min 82 low 114 high 146 spanned 32768 present 32768 so both zones have one memblock spanned and present. Onlining 39 should associate this block to the movable zone # echo online > /sys/devices/system/memory/memory39/state /proc/zoneinfo will now tell Node 0, zone Normal pages free 32765 min 80 low 112 high 144 spanned 32768 present 32768 -- Node 0, zone Movable pages free 65501 min 160 low 225 high 290 spanned 196608 present 65536 so we will have a movable zone which spans 6 memblocks, 2 present and 4 representing a hole. Offlining both movable blocks will lead to the zone with no present pages which is the expected behavior I believe. # echo offline > /sys/devices/system/memory/memory39/state # echo offline > /sys/devices/system/memory/memory34/state # grep -A6 "Movable\|Normal" /proc/zoneinfo Node 0, zone Normal pages free 32735 min 90 low 122 high 154 spanned 32768 present 32768 -- Node 0, zone Movable pages free 0 min 0 low 0 high 0 spanned 196608 present 0 As a bonus we will get a nice cleanup in the memory hotplug codebase. This patch (of 16): init_currently_empty_zone doesn't have any error to return yet it is still an int and callers try to be defensive and try to handle potential error. Remove this nonsense and simplify all callers. This patch shouldn't have any visible effect Link: http://lkml.kernel.org/r/20170515085827.16474-2-mhocko@kernel.orgSigned-off-by:Balbir Singh <bsingharora@gmail.com> Acked-by:
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Huang Ying authored
If there is no compound map for a THP (Transparent Huge Page), it is possible that the map count of some sub-pages of the THP is 0. So it is better to split the THP before swapping out. In this way, the sub-pages not mapped will be freed, and we can avoid the unnecessary swap out operations for these sub-pages. Link: http://lkml.kernel.org/r/20170515112522.32457-6-ying.huang@intel.comSigned-off-by:
"Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shli@kernel.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by:
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Huang Ying authored
To swap out THP (Transparent Huage Page), before splitting the THP, the swap cluster will be allocated and the THP will be added into the swap cache. But it is possible that the THP cannot be split, so that we must delete the THP from the swap cache and free the swap cluster. To avoid that, in this patch, whether the THP can be split is checked firstly. The check can only be done racy, but it is good enough for most cases. With the patch, the swap out throughput improves 3.6% (from about 4.16GB/s to about 4.31GB/s) in the vm-scalability swap-w-seq test case with 8 processes. The test is done on a Xeon E5 v3 system. The swap device used is a RAM simulated PMEM (persistent memory) device. To test the sequential swapping out, the test case creates 8 processes, which sequentially allocate and write to the anonymous pages until the RAM and part of the swap device is used up. Link: http://lkml.kernel.org/r/20170515112522.32457-5-ying.huang@intel.comSigned-off-by:
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