1. 16 Jul, 2020 1 commit
    • Christian Borntraeger's avatar
      KVM: s390: reduce number of IO pins to 1 · 34314cc6
      Christian Borntraeger authored
      [ Upstream commit 77491129 ]
      
      The current number of KVM_IRQCHIP_NUM_PINS results in an order 3
      allocation (32kb) for each guest start/restart. This can result in OOM
      killer activity even with free swap when the memory is fragmented
      enough:
      
      kernel: qemu-system-s39 invoked oom-killer: gfp_mask=0x440dc0(GFP_KERNEL_ACCOUNT|__GFP_COMP|__GFP_ZERO), order=3, oom_score_adj=0
      kernel: CPU: 1 PID: 357274 Comm: qemu-system-s39 Kdump: loaded Not tainted 5.4.0-29-generic #33-Ubuntu
      kernel: Hardware name: IBM 8562 T02 Z06 (LPAR)
      kernel: Call Trace:
      kernel: ([<00000001f848fe2a>] show_stack+0x7a/0xc0)
      kernel:  [<00000001f8d3437a>] dump_stack+0x8a/0xc0
      kernel:  [<00000001f8687032>] dump_header+0x62/0x258
      kernel:  [<00000001f8686122>] oom_kill_process+0x172/0x180
      kernel:  [<00000001f8686abe>] out_of_memory+0xee/0x580
      kernel:  [<00000001f86e66b8>] __alloc_pages_slowpath+0xd18/0xe90
      kernel:  [<00000001f86e6ad4>] __alloc_pages_nodemask+0x2a4/0x320
      kernel:  [<00000001f86b1ab4>] kmalloc_order+0x34/0xb0
      kernel:  [<00000001f86b1b62>] kmalloc_order_trace+0x32/0xe0
      kernel:  [<00000001f84bb806>] kvm_set_irq_routing+0xa6/0x2e0
      kernel:  [<00000001f84c99a4>] kvm_arch_vm_ioctl+0x544/0x9e0
      kernel:  [<00000001f84b8936>] kvm_vm_ioctl+0x396/0x760
      kernel:  [<00000001f875df66>] do_vfs_ioctl+0x376/0x690
      kernel:  [<00000001f875e304>] ksys_ioctl+0x84/0xb0
      kernel:  [<00000001f875e39a>] __s390x_sys_ioctl+0x2a/0x40
      kernel:  [<00000001f8d55424>] system_call+0xd8/0x2c8
      
      As far as I can tell s390x does not use the iopins as we bail our for
      anything other than KVM_IRQ_ROUTING_S390_ADAPTER and the chip/pin is
      only used for KVM_IRQ_ROUTING_IRQCHIP. So let us use a small number to
      reduce the memory footprint.
      Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
      Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
      Link: https://lore.kernel.org/r/20200617083620.5409-1-borntraeger@de.ibm.comSigned-off-by: default avatarSasha Levin <sashal@kernel.org>
      34314cc6
  2. 09 Jul, 2020 36 commits
  3. 01 Jul, 2020 3 commits