1. 25 Mar, 2020 2 commits
  2. 24 Mar, 2020 27 commits
  3. 23 Mar, 2020 7 commits
  4. 22 Mar, 2020 4 commits
    • Linus Torvalds's avatar
      Merge tag 'for-5.6-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux · 67d584e3
      Linus Torvalds authored
      Pull btrfs fixes from David Sterba:
       "Two fixes.
      
        The first is a regression: when dropping some incompat bits the
        conditions were reversed. The other is a fix for rename whiteout
        potentially leaving stack memory linked to a list"
      
      * tag 'for-5.6-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
        btrfs: fix removal of raid[56|1c34} incompat flags after removing block group
        btrfs: fix log context list corruption after rename whiteout error
      67d584e3
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · b3c03db6
      Linus Torvalds authored
      Merge misc fixes from Andrew Morton:
       "10 fixes"
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>:
        x86/mm: split vmalloc_sync_all()
        mm, slub: prevent kmalloc_node crashes and memory leaks
        mm/mmu_notifier: silence PROVE_RCU_LIST warnings
        epoll: fix possible lost wakeup on epoll_ctl() path
        mm: do not allow MADV_PAGEOUT for CoW pages
        mm, memcg: throttle allocators based on ancestral memory.high
        mm, memcg: fix corruption on 64-bit divisor in memory.high throttling
        page-flags: fix a crash at SetPageError(THP_SWAP)
        mm/hotplug: fix hot remove failure in SPARSEMEM|!VMEMMAP case
        memcg: fix NULL pointer dereference in __mem_cgroup_usage_unregister_event
      b3c03db6
    • Joerg Roedel's avatar
      x86/mm: split vmalloc_sync_all() · 763802b5
      Joerg Roedel authored
      Commit 3f8fd02b ("mm/vmalloc: Sync unmappings in
      __purge_vmap_area_lazy()") introduced a call to vmalloc_sync_all() in
      the vunmap() code-path.  While this change was necessary to maintain
      correctness on x86-32-pae kernels, it also adds additional cycles for
      architectures that don't need it.
      
      Specifically on x86-64 with CONFIG_VMAP_STACK=y some people reported
      severe performance regressions in micro-benchmarks because it now also
      calls the x86-64 implementation of vmalloc_sync_all() on vunmap().  But
      the vmalloc_sync_all() implementation on x86-64 is only needed for newly
      created mappings.
      
      To avoid the unnecessary work on x86-64 and to gain the performance
      back, split up vmalloc_sync_all() into two functions:
      
      	* vmalloc_sync_mappings(), and
      	* vmalloc_sync_unmappings()
      
      Most call-sites to vmalloc_sync_all() only care about new mappings being
      synchronized.  The only exception is the new call-site added in the
      above mentioned commit.
      
      Shile Zhang directed us to a report of an 80% regression in reaim
      throughput.
      
      Fixes: 3f8fd02b ("mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()")
      Reported-by: default avatarkernel test robot <oliver.sang@intel.com>
      Reported-by: default avatarShile Zhang <shile.zhang@linux.alibaba.com>
      Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Tested-by: default avatarBorislav Petkov <bp@suse.de>
      Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>	[GHES]
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: <stable@vger.kernel.org>
      Link: http://lkml.kernel.org/r/20191009124418.8286-1-joro@8bytes.org
      Link: https://lists.01.org/hyperkitty/list/lkp@lists.01.org/thread/4D3JPPHBNOSPFK2KEPC6KGKS6J25AIDB/
      Link: http://lkml.kernel.org/r/20191113095530.228959-1-shile.zhang@linux.alibaba.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      763802b5
    • Vlastimil Babka's avatar
      mm, slub: prevent kmalloc_node crashes and memory leaks · 0715e6c5
      Vlastimil Babka authored
      Sachin reports [1] a crash in SLUB __slab_alloc():
      
        BUG: Kernel NULL pointer dereference on read at 0x000073b0
        Faulting instruction address: 0xc0000000003d55f4
        Oops: Kernel access of bad area, sig: 11 [#1]
        LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
        Modules linked in:
        CPU: 19 PID: 1 Comm: systemd Not tainted 5.6.0-rc2-next-20200218-autotest #1
        NIP:  c0000000003d55f4 LR: c0000000003d5b94 CTR: 0000000000000000
        REGS: c0000008b37836d0 TRAP: 0300   Not tainted  (5.6.0-rc2-next-20200218-autotest)
        MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 24004844  XER: 00000000
        CFAR: c00000000000dec4 DAR: 00000000000073b0 DSISR: 40000000 IRQMASK: 1
        GPR00: c0000000003d5b94 c0000008b3783960 c00000000155d400 c0000008b301f500
        GPR04: 0000000000000dc0 0000000000000002 c0000000003443d8 c0000008bb398620
        GPR08: 00000008ba2f0000 0000000000000001 0000000000000000 0000000000000000
        GPR12: 0000000024004844 c00000001ec52a00 0000000000000000 0000000000000000
        GPR16: c0000008a1b20048 c000000001595898 c000000001750c18 0000000000000002
        GPR20: c000000001750c28 c000000001624470 0000000fffffffe0 5deadbeef0000122
        GPR24: 0000000000000001 0000000000000dc0 0000000000000002 c0000000003443d8
        GPR28: c0000008b301f500 c0000008bb398620 0000000000000000 c00c000002287180
        NIP ___slab_alloc+0x1f4/0x760
        LR __slab_alloc+0x34/0x60
        Call Trace:
          ___slab_alloc+0x334/0x760 (unreliable)
          __slab_alloc+0x34/0x60
          __kmalloc_node+0x110/0x490
          kvmalloc_node+0x58/0x110
          mem_cgroup_css_online+0x108/0x270
          online_css+0x48/0xd0
          cgroup_apply_control_enable+0x2ec/0x4d0
          cgroup_mkdir+0x228/0x5f0
          kernfs_iop_mkdir+0x90/0xf0
          vfs_mkdir+0x110/0x230
          do_mkdirat+0xb0/0x1a0
          system_call+0x5c/0x68
      
      This is a PowerPC platform with following NUMA topology:
      
        available: 2 nodes (0-1)
        node 0 cpus:
        node 0 size: 0 MB
        node 0 free: 0 MB
        node 1 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
        node 1 size: 35247 MB
        node 1 free: 30907 MB
        node distances:
        node   0   1
          0:  10  40
          1:  40  10
      
        possible numa nodes: 0-31
      
      This only happens with a mmotm patch "mm/memcontrol.c: allocate
      shrinker_map on appropriate NUMA node" [2] which effectively calls
      kmalloc_node for each possible node.  SLUB however only allocates
      kmem_cache_node on online N_NORMAL_MEMORY nodes, and relies on
      node_to_mem_node to return such valid node for other nodes since commit
      a561ce00 ("slub: fall back to node_to_mem_node() node if allocating
      on memoryless node").  This is however not true in this configuration
      where the _node_numa_mem_ array is not initialized for nodes 0 and 2-31,
      thus it contains zeroes and get_partial() ends up accessing
      non-allocated kmem_cache_node.
      
      A related issue was reported by Bharata (originally by Ramachandran) [3]
      where a similar PowerPC configuration, but with mainline kernel without
      patch [2] ends up allocating large amounts of pages by kmalloc-1k
      kmalloc-512.  This seems to have the same underlying issue with
      node_to_mem_node() not behaving as expected, and might probably also
      lead to an infinite loop with CONFIG_SLUB_CPU_PARTIAL [4].
      
      This patch should fix both issues by not relying on node_to_mem_node()
      anymore and instead simply falling back to NUMA_NO_NODE, when
      kmalloc_node(node) is attempted for a node that's not online, or has no
      usable memory.  The "usable memory" condition is also changed from
      node_present_pages() to N_NORMAL_MEMORY node state, as that is exactly
      the condition that SLUB uses to allocate kmem_cache_node structures.
      The check in get_partial() is removed completely, as the checks in
      ___slab_alloc() are now sufficient to prevent get_partial() being
      reached with an invalid node.
      
      [1] https://lore.kernel.org/linux-next/3381CD91-AB3D-4773-BA04-E7A072A63968@linux.vnet.ibm.com/
      [2] https://lore.kernel.org/linux-mm/fff0e636-4c36-ed10-281c-8cdb0687c839@virtuozzo.com/
      [3] https://lore.kernel.org/linux-mm/20200317092624.GB22538@in.ibm.com/
      [4] https://lore.kernel.org/linux-mm/088b5996-faae-8a56-ef9c-5b567125ae54@suse.cz/
      
      Fixes: a561ce00 ("slub: fall back to node_to_mem_node() node if allocating on memoryless node")
      Reported-by: default avatarSachin Sant <sachinp@linux.vnet.ibm.com>
      Reported-by: default avatarPUVICHAKRAVARTHY RAMACHANDRAN <puvichakravarthy@in.ibm.com>
      Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Tested-by: default avatarSachin Sant <sachinp@linux.vnet.ibm.com>
      Tested-by: default avatarBharata B Rao <bharata@linux.ibm.com>
      Reviewed-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Michal Hocko <mhocko@kernel.org>
      Cc: Christopher Lameter <cl@linux.com>
      Cc: linuxppc-dev@lists.ozlabs.org
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Nathan Lynch <nathanl@linux.ibm.com>
      Cc: <stable@vger.kernel.org>
      Link: http://lkml.kernel.org/r/20200320115533.9604-1-vbabka@suse.czDebugged-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0715e6c5