- 07 Aug, 2020 40 commits
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Walter Wu authored
Test call_rcu() call stack recording and verify whether it correctly is printed in KASAN report. Signed-off-by:
Walter Wu <walter-zh.wu@mediatek.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Tested-by:
Dmitry Vyukov <dvyukov@google.com> Reviewed-by:
Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Link: http://lkml.kernel.org/r/20200601051045.1294-1-walter-zh.wu@mediatek.comSigned-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Walter Wu authored
Move free track from kasan_alloc_meta to kasan_free_meta in order to make struct kasan_alloc_meta and kasan_free_meta size are both 16 bytes. It is a good size because it is the minimal redzone size and a good number of alignment. For free track, we make some modifications as shown below: 1) Remove the free_track from struct kasan_alloc_meta. 2) Add the free_track into struct kasan_free_meta. 3) Add a macro KASAN_KMALLOC_FREETRACK in order to check whether it can print free stack in KASAN report. [1]https://bugzilla.kernel.org/show_bug.cgi?id=198437 [walter-zh.wu@mediatek.com: build fix] Link: http://lkml.kernel.org/r/20200710162440.23887-1-walter-zh.wu@mediatek.comSuggested-by:
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Walter Wu authored
Patch series "kasan: memorize and print call_rcu stack", v8. This patchset improves KASAN reports by making them to have call_rcu() call stack information. It is useful for programmers to solve use-after-free or double-free memory issue. The KASAN report was as follows(cleaned up slightly): BUG: KASAN: use-after-free in kasan_rcu_reclaim+0x58/0x60 Freed by task 0: kasan_save_stack+0x24/0x50 kasan_set_track+0x24/0x38 kasan_set_free_info+0x18/0x20 __kasan_slab_free+0x10c/0x170 kasan_slab_free+0x10/0x18 kfree+0x98/0x270 kasan_rcu_reclaim+0x1c/0x60 Last call_rcu(): kasan_save_stack+0x24/0x50 kasan_record_aux_stack+0xbc/0xd0 call_rcu+0x8c/0x580 kasan_rcu_uaf+0xf4/0xf8 Generic KASAN will record the last two call_rcu() call stacks and print up to 2 call_rcu() call stacks in KASAN report. it is only suitable for generic KASAN. This feature considers the size of struct kasan_alloc_meta and kasan_free_meta, we try to optimize the structure layout and size, lets it get better memory consumption. [1]https://bugzilla.kernel.org/show_bug.cgi?id=198437 [2]https://groups.google.com/forum/#!searchin/kasan-dev/better$20stack$20traces$20for$20rcu%7Csort:date/kasan-dev/KQsjT_88hDE/7rNUZprRBgAJ This patch (of 4): This feature will record the last two call_rcu() call stacks and prints up to 2 call_rcu() call stacks in KASAN report. When call_rcu() is called, we store the call_rcu() call stack into slub alloc meta-data, so that the KASAN report can print rcu stack. [1]https://bugzilla.kernel.org/show_bug.cgi?id=198437 [2]https://groups.google.com/forum/#!searchin/kasan-dev/better$20stack$20traces$20for$20rcu%7Csort:date/kasan-dev/KQsjT_88hDE/7rNUZprRBgAJ [walter-zh.wu@mediatek.com: build fix] Link: http://lkml.kernel.org/r/20200710162401.23816-1-walter-zh.wu@mediatek.comSuggested-by:
Paul E. McKenney <paulmck@kernel.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthias Brugger <matthias.bgg@gmail.com> Link: http://lkml.kernel.org/r/20200710162123.23713-1-walter-zh.wu@mediatek.com Link: http://lkml.kernel.org/r/20200601050847.1096-1-walter-zh.wu@mediatek.com Link: http://lkml.kernel.org/r/20200601050927.1153-1-walter-zh.wu@mediatek.comSigned-off-by:
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Marco Elver authored
Updates the recently changed compiler requirements for KASAN. In particular, we require GCC >= 8.3.0, and add a note that Clang 11 supports OOB detection of globals. Fixes: 7b861a53 ("kasan: Bump required compiler version") Fixes: acf7b0bf ("kasan: Fix required compiler version") Signed-off-by:
Marco Elver <elver@google.com> Signed-off-by:
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Marco Elver authored
Turn 'KASAN' into a menuconfig, to avoid cluttering its parent menu with the suboptions if enabled. Use 'if KASAN ... endif' instead of having to 'depend on KASAN' for each entry. Signed-off-by:
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Uladzislau Rezki (Sony) authored
Get rid of BUG() macro, that should be used only when a critical situation happens and a system is not able to function anymore. Replace it with WARN() macro instead, dump some extra information about start/end addresses of both VAs which overlap. Such overlap data can help to figure out what happened making further analysis easier. For example if both areas are identical it could mean a double free. A recovery process consists of declining all further steps regarding inserting of conflicting overlap range. In that sense find_va_links() now can return NULL, so its return value has to be checked by callers. Side effect of such process is it can leak memory, but it is better than just killing a machine for no good reason. Apart of that a debugging process can be done on alive system. Signed-off-by:
Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by:
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Mike Rapoport authored
'addr' is set to 'start' and then a few lines afterwards 'start' is set to 'addr'. Remove the second asignment. Fixes: 2ba3e694 ("mm/vmalloc: track which page-table levels were modified") Signed-off-by:
Mike Rapoport <rppt@linux.ibm.com> Signed-off-by:
David Hildenbrand <david@redhat.com> Cc: Joerg Roedel <jroedel@suse.de> Link: http://lkml.kernel.org/r/20200707163226.374685-1-rppt@kernel.orgSigned-off-by:
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Uladzislau Rezki (Sony) authored
Reflect information about the author, date and year when the KVA rework was done. Signed-off-by:
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Uladzislau Rezki (Sony) authored
An augment_tree_propagate_from() function uses its own implementation that populates a tree from the specified node toward a root node. On the other hand the RB_DECLARE_CALLBACKS_MAX macro provides the "propagate()" callback that does exactly the same. Having two similar functions does not make sense and is redundant. Reuse "built in" functionality to the macros. So the code size gets reduced. Signed-off-by:
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Uladzislau Rezki (Sony) authored
This function is for debug purpose only. Currently it uses recursion for tree traversal, checking an augmented value of each node to find out if it is valid or not. The recursion can corrupt the stack because the tree can be huge if synthetic tests are applied. To prevent it, navigate the tree from bottom to upper levels using a regular list instead, because nodes are linked among each other also. It is faster and without recursion. Signed-off-by:
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Uladzislau Rezki (Sony) authored
Currently when a VA is deallocated and is about to be placed back to the tree, it can be either: merged with next/prev neighbors or inserted if not coalesced. On those steps the tree can be populated several times. For example when both neighbors are merged. It can be avoided and simplified in fact. Therefore do it only once when VA points to final merged area, after all manipulations: merging/removing/inserting. Signed-off-by:
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Matthew Wilcox (Oracle) authored
The radix tree of vmap blocks is simpler to express as an XArray. Reduces both the text and data sizes of the object file and eliminates a user of the radix tree preload API. Signed-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by:
William Kucharski <william.kucharski@oracle.com> Link: http://lkml.kernel.org/r/20200603171448.5894-1-willy@infradead.orgSigned-off-by:
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Mike Rapoport authored
After removal of CONFIG_HAVE_MEMBLOCK_NODE_MAP we have two equivalent functions that call memory_present() for each region in memblock.memory: sparse_memory_present_with_active_regions() and membocks_present(). Moreover, all architectures have a call to either of these functions preceding the call to sparse_init() and in the most cases they are called one after the other. Mark the regions from memblock.memory as present during sparce_init() by making sparse_init() call memblocks_present(), make memblocks_present() and memory_present() functions static and remove redundant sparse_memory_present_with_active_regions() function. Also remove no longer required HAVE_MEMORY_PRESENT configuration option. Signed-off-by:
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Wei Yang authored
There are two code path which invoke __populate_section_memmap() * sparse_init_nid() * sparse_add_section() For both case, we are sure the memory range is sub-section aligned. * we pass PAGES_PER_SECTION to sparse_init_nid() * we check range by check_pfn_span() before calling sparse_add_section() Also, the counterpart of __populate_section_memmap(), we don't do such calculation and check since the range is checked by check_pfn_span() in __remove_pages(). Clear the calculation and check to keep it simple and comply with its counterpart. Signed-off-by:Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by:
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Wei Yang authored
For early sections, its memmap is handled specially even sub-section is enabled. The memmap could only be populated as a whole. Quoted from the comment of section_activate(): * The early init code does not consider partially populated * initial sections, it simply assumes that memory will never be * referenced. If we hot-add memory into such a section then we * do not need to populate the memmap and can simply reuse what * is already there. While current section_deactivate() breaks this rule. When hot-remove a sub-section, section_deactivate() would depopulate its memmap. The consequence is if we hot-add this subsection again, its memmap never get proper populated. We can reproduce the case by following steps: 1. Hacking qemu to allow sub-section early section : diff --git a/hw/i386/pc.c b/hw/i386/pc.c : index 51b3050d01..c6a78d83c0 100644 : --- a/hw/i386/pc.c : +++ b/hw/i386/pc.c : @@ -1010,7 +1010,7 @@ void pc_memory_init(PCMachineState *pcms, : } : : machine->device_memory->base = : - ROUND_UP(0x100000000ULL + x86ms->above_4g_mem_size, 1 * GiB); : + 0x100000000ULL + x86ms->above_4g_mem_size; : : if (pcmc->enforce_aligned_dimm) { : /* size device region assuming 1G page max alignment per slot */ 2. Bootup qemu with PSE disabled and a sub-section aligned memory size Part of the qemu command would look like this: sudo x86_64-softmmu/qemu-system-x86_64 \ --enable-kvm -cpu host,pse=off \ -m 4160M,maxmem=20G,slots=1 \ -smp sockets=2,cores=16 \ -numa node,nodeid=0,cpus=0-1 -numa node,nodeid=1,cpus=2-3 \ -machine pc,nvdimm \ -nographic \ -object memory-backend-ram,id=mem0,size=8G \ -device nvdimm,id=vm0,memdev=mem0,node=0,addr=0x144000000,label-size=128k 3. Re-config a pmem device with sub-section size in guest ndctl create-namespace --force --reconfig=namespace0.0 --mode=devdax --size=16M Then you would see the following call trace: pmem0: detected capacity change from 0 to 16777216 BUG: unable to handle page fault for address: ffffec73c51000b4 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 81ff8067 P4D 81ff8067 PUD 81ff7067 PMD 1437cb067 PTE 0 Oops: 0002 [#1] SMP NOPTI CPU: 16 PID: 1348 Comm: ndctl Kdump: loaded Tainted: G W 5.8.0-rc2+ #24 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.4 RIP: 0010:memmap_init_zone+0x154/0x1c2 Code: 77 16 f6 40 10 02 74 10 48 03 48 08 48 89 cb 48 c1 eb 0c e9 3a ff ff ff 48 89 df 48 c1 e7 06 48f RSP: 0018:ffffbdc7011a39b0 EFLAGS: 00010282 RAX: ffffec73c5100088 RBX: 0000000000144002 RCX: 0000000000144000 RDX: 0000000000000004 RSI: 007ffe0000000000 RDI: ffffec73c5100080 RBP: 027ffe0000000000 R08: 0000000000000001 R09: ffff9f8d38f6d708 R10: ffffec73c0000000 R11: 0000000000000000 R12: 0000000000000004 R13: 0000000000000001 R14: 0000000000144200 R15: 0000000000000000 FS: 00007efe6b65d780(0000) GS:ffff9f8d3f780000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffec73c51000b4 CR3: 000000007d718000 CR4: 0000000000340ee0 Call Trace: move_pfn_range_to_zone+0x128/0x150 memremap_pages+0x4e4/0x5a0 devm_memremap_pages+0x1e/0x60 dev_dax_probe+0x69/0x160 [device_dax] really_probe+0x298/0x3c0 driver_probe_device+0xe1/0x150 ? driver_allows_async_probing+0x50/0x50 bus_for_each_drv+0x7e/0xc0 __device_attach+0xdf/0x160 bus_probe_device+0x8e/0xa0 device_add+0x3b9/0x740 __devm_create_dev_dax+0x127/0x1c0 __dax_pmem_probe+0x1f2/0x219 [dax_pmem_core] dax_pmem_probe+0xc/0x1b [dax_pmem] nvdimm_bus_probe+0x69/0x1c0 [libnvdimm] really_probe+0x147/0x3c0 driver_probe_device+0xe1/0x150 device_driver_attach+0x53/0x60 bind_store+0xd1/0x110 kernfs_fop_write+0xce/0x1b0 vfs_write+0xb6/0x1a0 ksys_write+0x5f/0xe0 do_syscall_64+0x4d/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: ba72b4c8 ("mm/sparsemem: support sub-section hotplug") Signed-off-by: -
Ricardo Cañuelo authored
Add a test suite for the mincore() syscall. It tests most of its use cases as well as its interface. Tests implemented: - basic interface test - behavior on anonymous mappings - behavior on anonymous mappings with huge tlb pages - file-backed mapping with a regular file - file-backed mapping with a tmpfs file Signed-off-by:
Ricardo Cañuelo <ricardo.canuelo@collabora.com> Signed-off-by:
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Wei Yang authored
After previous cleanup, extent is the minimal step for both source and destination. This means when extent is HPAGE_PMD_SIZE or PMD_SIZE, old_addr and new_addr are properly aligned too. Since these two functions are only invoked in move_page_tables, it is safe to remove the check now. Signed-off-by:
Dmitry Osipenko <digetx@gmail.com> Acked-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Xu <peterx@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Thomas Hellstrom <thellstrom@vmware.com> Cc: Thomas Hellstrom (VMware) <thomas_os@shipmail.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <yang.shi@linux.alibaba.com> Link: http://lkml.kernel.org/r/20200708095028.41706-4-richard.weiyang@linux.alibaba.comSigned-off-by:
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Wei Yang authored
Page tables is moved on the base of PMD. This requires both source and destination range should meet the requirement. Current code works well since move_huge_pmd() and move_normal_pmd() would check old_addr and new_addr again. And then return to move_ptes() if the either of them is not aligned. Instead of calculating the extent separately, it is better to calculate in one place, so we know it is not necessary to try move pmd. By doing so, the logic seems a little clear. Signed-off-by:
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Wei Yang authored
Patch series "mm/mremap: cleanup move_page_tables() a little", v5. move_page_tables() tries to move page table by PMD or PTE. The root reason is if it tries to move PMD, both old and new range should be PMD aligned. But current code calculate old range and new range separately. This leads to some redundant check and calculation. This cleanup tries to consolidate the range check in one place to reduce some extra range handling. This patch (of 3): old_end is passed to these two functions to check whether there is enough space to do the move, while this check is done before invoking these functions. These two functions only would be invoked when extent meets the requirement and there is one check before invoking these functions: if (extent > old_end - old_addr) extent = old_end - old_addr; This implies (old_end - old_addr) won't fail the check in these two functions. Signed-off-by: -
Peter Collingbourne authored
The current split between do_mmap() and do_mmap_pgoff() was introduced in commit 1fcfd8db ("mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff()") to support MPX. The wrapper function do_mmap_pgoff() always passed 0 as the value of the vm_flags argument to do_mmap(). However, MPX support has subsequently been removed from the kernel and there were no more direct callers of do_mmap(); all calls were going via do_mmap_pgoff(). Simplify the code by removing do_mmap_pgoff() and changing all callers to directly call do_mmap(), which now no longer takes a vm_flags argument. Signed-off-by:
Peter Collingbourne <pcc@google.com> Signed-off-by:
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Miaohe Lin authored
The vm_flags may be changed after call_mmap() because drivers may set some flags for their own purpose. As a result, we failed to merge the adjacent vma due to the different vm_flags as userspace can't pass in the same one. Try to merge vma after call_mmap() to fix this issue. Signed-off-by:
Hongxiang Lou <louhongxiang@huawei.com> Signed-off-by:
Miaohe Lin <linmiaohe@huawei.com> Signed-off-by:
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Anshuman Khandual authored
Device memory ranges when getting hot added into ZONE_DEVICE, might require their vmemmap mapping's backing memory to be allocated from their own range instead of consuming system memory. This prevents large system memory usage for potentially large device memory ranges. Device driver communicates this request via vmem_altmap structure. Architecture needs to take this request into account while creating and tearing down vemmmap mappings. This enables vmem_altmap support in vmemmap_populate() and vmemmap_free() which includes vmemmap_populate_basepages() used for ARM64_16K_PAGES and ARM64_64K_PAGES configs. Signed-off-by:
Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by:
Jia He <justin.he@arm.com> Reviewed-by:
Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Steve Capper <steve.capper@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Hsin-Yi Wang <hsinyi@chromium.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/1594004178-8861-4-git-send-email-anshuman.khandual@arm.comSigned-off-by:
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Anshuman Khandual authored
There are many instances where vmemap allocation is often switched between regular memory and device memory just based on whether altmap is available or not. vmemmap_alloc_block_buf() is used in various platforms to allocate vmemmap mappings. Lets also enable it to handle altmap based device memory allocation along with existing regular memory allocations. This will help in avoiding the altmap based allocation switch in many places. To summarize there are two different methods to call vmemmap_alloc_block_buf(). vmemmap_alloc_block_buf(size, node, NULL) /* Allocate from system RAM */ vmemmap_alloc_block_buf(size, node, altmap) /* Allocate from altmap */ This converts altmap_alloc_block_buf() into a static function, drops it's entry from the header and updates Documentation/vm/memory-model.rst. Suggested-by:
Robin Murphy <robin.murphy@arm.com> Signed-off-by:
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Anshuman Khandual authored
Patch series "arm64: Enable vmemmap mapping from device memory", v4. This series enables vmemmap backing memory allocation from device memory ranges on arm64. But before that, it enables vmemmap_populate_basepages() and vmemmap_alloc_block_buf() to accommodate struct vmem_altmap based alocation requests. This patch (of 3): vmemmap_populate_basepages() is used across platforms to allocate backing memory for vmemmap mapping. This is used as a standard default choice or as a fallback when intended huge pages allocation fails. This just creates entire vmemmap mapping with base pages (PAGE_SIZE). On arm64 platforms, vmemmap_populate_basepages() is called instead of the platform specific vmemmap_populate() when ARM64_SWAPPER_USES_SECTION_MAPS is not enabled as in case for ARM64_16K_PAGES and ARM64_64K_PAGES configs. At present vmemmap_populate_basepages() does not support allocating from driver defined struct vmem_altmap while trying to create vmemmap mapping for a device memory range. It prevents ARM64_16K_PAGES and ARM64_64K_PAGES configs on arm64 from supporting device memory with vmemap_altmap request. This enables vmem_altmap support in vmemmap_populate_basepages() unlocking device memory allocation for vmemap mapping on arm64 platforms with 16K or 64K base page configs. Each architecture should evaluate and decide on subscribing device memory based base page allocation through vmemmap_populate_basepages(). Hence lets keep it disabled on all archs in order to preserve the existing semantics. A subsequent patch enables it on arm64. Signed-off-by:
Will Deacon <will@kernel.org> Acked-by:
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Feng Tang authored
When checking a performance change for will-it-scale scalability mmap test [1], we found very high lock contention for spinlock of percpu counter 'vm_committed_as': 94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave 48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap; 45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap; Actually this heavy lock contention is not always necessary. The 'vm_committed_as' needs to be very precise when the strict OVERCOMMIT_NEVER policy is set, which requires a rather small batch number for the percpu counter. So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and lift it to 64X for OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Also add a sysctl handler to adjust it when the policy is reconfigured. Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T desktop, and 2097%(20X) on a 4S/72C/144T server. We tested with test platforms in 0day (server, desktop and laptop), and 80%+ platforms shows improvements with that test. And whether it shows improvements depends on if the test mmap size is bigger than the batch number computed. And if the lift is 16X, 1/3 of the platforms will show improvements, though it should help the mmap/unmap usage generally, as Michal Hocko mentioned: : I believe that there are non-synthetic worklaods which would benefit from : a larger batch. E.g. large in memory databases which do large mmaps : during startups from multiple threads. [1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/Signed-off-by:Feng Tang <feng.tang@intel.com> Signed-off-by:
Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Qian Cai <cai@lca.pw> Cc: Kees Cook <keescook@chromium.org> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: kernel test robot <rong.a.chen@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1589611660-89854-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1592725000-73486-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1594389708-60781-5-git-send-email-feng.tang@intel.comSigned-off-by:
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Feng Tang authored
percpu_counter's accuracy is related to its batch size. For a percpu_counter with a big batch, its deviation could be big, so when the counter's batch is runtime changed to a smaller value for better accuracy, there could also be requirment to reduce the big deviation. So add a percpu-counter sync function to be run on each CPU. Reported-by:
kernel test robot <rong.a.chen@intel.com> Signed-off-by:
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Feng Tang authored
percpu_counter_sum_positive() will provide more accurate info. As with percpu_counter_read_positive(), in worst case the deviation could be 'batch * nr_cpus', which is totalram_pages/256 for now, and will be more when the batch gets enlarged. Its time cost is about 800 nanoseconds on a 2C/4T platform and 2~3 microseconds on a 2S/36C/72T Skylake server in normal case, and in worst case where vm_committed_as's spinlock is under severe contention, it costs 30~40 microseconds for the 2S/36C/72T Skylake sever, which should be fine for its only two users: /proc/meminfo and HyperV balloon driver's status trace per second. Signed-off-by:
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Feng Tang authored
Patch series "make vm_committed_as_batch aware of vm overcommit policy", v6. When checking a performance change for will-it-scale scalability mmap test [1], we found very high lock contention for spinlock of percpu counter 'vm_committed_as': 94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave 48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap; 45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap; Actually this heavy lock contention is not always necessary. The 'vm_committed_as' needs to be very precise when the strict OVERCOMMIT_NEVER policy is set, which requires a rather small batch number for the percpu counter. So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and enlarge it for not-so-strict OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T desktop, and 2097%(20X) on a 4S/72C/144T server. And for that case, whether it shows improvements depends on if the test mmap size is bigger than the batch number computed. We tested 10+ platforms in 0day (server, desktop and laptop). If we lift it to 64X, 80%+ platforms show improvements, and for 16X lift, 1/3 of the platforms will show improvements. And generally it should help the mmap/unmap usage,as Michal Hocko mentioned: : I believe that there are non-synthetic worklaods which would benefit : from a larger batch. E.g. large in memory databases which do large : mmaps during startups from multiple threads. Note: There are some style complain from checkpatch for patch 4, as sysctl handler declaration follows the similar format of sibling functions [1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/ This patch (of 4): Use the existing vm_memory_committed() instead, which is also convenient for future change. Signed-off-by: -
Zhen Lei authored
Look at the pseudo code below. It's very clear that, the judgement "!is_file_hugepages(file)" at 3) is duplicated to the one at 1), we can use "else if" to avoid it. And the assignment "retval = -EINVAL" at 2) is only needed by the branch 3), because "retval" will be overwritten at 4). No functional change, but it can reduce the code size. Maybe more clearer? Before: text data bss dec hex filename 28733 1590 1 30324 7674 mm/mmap.o After: text data bss dec hex filename 28701 1590 1 30292 7654 mm/mmap.o ====pseudo code====: if (!(flags & MAP_ANONYMOUS)) { ... 1) if (is_file_hugepages(file)) len = ALIGN(len, huge_page_size(hstate_file(file))); 2) retval = -EINVAL; 3) if (unlikely(flags & MAP_HUGETLB && !is_file_hugepages(file))) goto out_fput; } else if (flags & MAP_HUGETLB) { ... } ... 4) retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); out_fput: ... return retval; Signed-off-by:Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by:
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Joerg Roedel authored
The functions are only used in two source files, so there is no need for them to be in the global <linux/mm.h> header. Move them to the new <linux/pgalloc-track.h> header and include it only where needed. Signed-off-by:
Joerg Roedel <jroedel@suse.de> Signed-off-by:
Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Stafford Horne <shorne@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Matthew Wilcox <willy@infradead.org> Link: http://lkml.kernel.org/r/20200609120533.25867-1-joro@8bytes.orgSigned-off-by:
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Mike Rapoport authored
The functionality in lib/ioremap.c deals with pagetables, vmalloc and caches, so it naturally belongs to mm/ Moving it there will also allow declaring p?d_alloc_track functions in an header file inside mm/ rather than having those declarations in include/linux/mm.h Suggested-by:
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Mike Rapoport authored
Most architectures define pgd_free() as a wrapper for free_page(). Provide a generic version in asm-generic/pgalloc.h and enable its use for most architectures. Signed-off-by:
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Mike Rapoport authored
Several architectures define pud_alloc_one() as a wrapper for __get_free_page() and pud_free() as a wrapper for free_page(). Provide a generic implementation in asm-generic/pgalloc.h and use it where appropriate. Signed-off-by:
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Mike Rapoport authored
For most architectures that support >2 levels of page tables, pmd_alloc_one() is a wrapper for __get_free_pages(), sometimes with __GFP_ZERO and sometimes followed by memset(0) instead. More elaborate versions on arm64 and x86 account memory for the user page tables and call to pgtable_pmd_page_ctor() as the part of PMD page initialization. Move the arm64 version to include/asm-generic/pgalloc.h and use the generic version on several architectures. The pgtable_pmd_page_ctor() is a NOP when ARCH_ENABLE_SPLIT_PMD_PTLOCK is not enabled, so there is no functional change for most architectures except of the addition of __GFP_ACCOUNT for allocation of user page tables. The pmd_free() is a wrapper for free_page() in all the cases, so no functional change here. Signed-off-by:
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Mike Rapoport authored
xtensa clears PTEs during allocation of the page tables and pte_clear() sets the PTE to a non-zero value. Splitting ptes_clear() helper out of pte_alloc_one() and pte_alloc_one_kernel() allows reuse of base generic allocation methods (__pte_alloc_one() and __pte_alloc_one_kernel()) and the common GFP mask for page table allocations. The pte_free() and pte_free_kernel() implementations on xtensa are identical to the generic ones and can be dropped. [jcmvbkbc@gmail.com: xtensa: fix closing endif comment] Link: http://lkml.kernel.org/r/20200721024751.1257-1-jcmvbkbc@gmail.comSigned-off-by:
Max Filippov <jcmvbkbc@gmail.com> Signed-off-by:
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Mike Rapoport authored
Replace pte_alloc_one(), pte_free() and pte_free_kernel() with the generic implementation. The only actual functional change is the addition of __GFP_ACCOUT for the allocation of the user page tables. The pte_alloc_one_kernel() is kept back because its implementation on openrisc is different than the generic one. Signed-off-by:
Stafford Horne <shorne@gmail.com> Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Joerg Roedel <joro@8bytes.org> Cc: Joerg Roedel <jroedel@suse.de> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Matthew Wilcox <willy@infradead.org> Link: http://lkml.kernel.org/r/20200627143453.31835-3-rppt@kernel.orgSigned-off-by:
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Mike Rapoport authored
Patch series "mm: cleanup usage of <asm/pgalloc.h>" Most architectures have very similar versions of pXd_alloc_one() and pXd_free_one() for intermediate levels of page table. These patches add generic versions of these functions in <asm-generic/pgalloc.h> and enable use of the generic functions where appropriate. In addition, functions declared and defined in <asm/pgalloc.h> headers are used mostly by core mm and early mm initialization in arch and there is no actual reason to have the <asm/pgalloc.h> included all over the place. The first patch in this series removes unneeded includes of <asm/pgalloc.h> In the end it didn't work out as neatly as I hoped and moving pXd_alloc_track() definitions to <asm-generic/pgalloc.h> would require unnecessary changes to arches that have custom page table allocations, so I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local to mm/. This patch (of 8): In most cases <asm/pgalloc.h> header is required only for allocations of page table memory. Most of the .c files that include that header do not use symbols declared in <asm/pgalloc.h> and do not require that header. As for the other header files that used to include <asm/pgalloc.h>, it is possible to move that include into the .c file that actually uses symbols from <asm/pgalloc.h> and drop the include from the header file. The process was somewhat automated using sed -i -E '/[<"]asm\/pgalloc\.h/d' \ $(grep -L -w -f /tmp/xx \ $(git grep -E -l '[<"]asm/pgalloc\.h')) where /tmp/xx contains all the symbols defined in arch/*/include/asm/pgalloc.h. [rppt@linux.ibm.com: fix powerpc warning] Signed-off-by: -
Alex Zhang authored
This function implicitly assumes that the addr passed in is page aligned. A non page aligned addr could ultimately cause a kernel bug in remap_pte_range as the exit condition in the logic loop may never be satisfied. This patch documents the need for the requirement, as well as explicitly adds a check for it. Signed-off-by:
Alex Zhang <zhangalex@google.com> Signed-off-by:
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Ralph Campbell authored
In zap_pte_range(), the check for non_swap_entry() and is_device_private_entry() is unnecessary since the latter is sufficient to determine if the page is a device private page. Remove the test for non_swap_entry() to simplify the code and for clarity. Signed-off-by:
Ralph Campbell <rcampbell@nvidia.com> Signed-off-by:
Jason Gunthorpe <jgg@mellanox.com> Acked-by:
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Michal Koutný authored
When workload runs in cgroups that aren't directly below root cgroup and their parent specifies reclaim protection, it may end up ineffective. The reason is that propagate_protected_usage() is not called in all hierarchy up. All the protected usage is incorrectly accumulated in the workload's parent. This means that siblings_low_usage is overestimated and effective protection underestimated. Even though it is transitional phenomenon (uncharge path does correct propagation and fixes the wrong children_low_usage), it can undermine the intended protection unexpectedly. We have noticed this problem while seeing a swap out in a descendant of a protected memcg (intermediate node) while the parent was conveniently under its protection limit and the memory pressure was external to that hierarchy. Michal has pinpointed this down to the wrong siblings_low_usage which led to the unwanted reclaim. The fix is simply updating children_low_usage in respective ancestors also in the charging path. Fixes: 23067153 ("mm: memory.low hierarchical behavior") Signed-off-by:
Michal Koutný <mkoutny@suse.com> Signed-off-by:
Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> [4.18+] Link: http://lkml.kernel.org/r/20200803153231.15477-1-mhocko@kernel.orgSigned-off-by:
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