* zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
@ 2016-05-20 20:28 Oleg Nesterov
2016-05-21 4:07 ` Tetsuo Handa
2016-05-23 7:29 ` Michal Hocko
0 siblings, 2 replies; 14+ messages in thread
From: Oleg Nesterov @ 2016-05-20 20:28 UTC (permalink / raw)
To: Andrew Morton, Andrea Arcangeli, Mel Gorman, Michal Hocko
Cc: linux-kernel, linux-mm
Hello,
Recently I hit the problem, _sometimes_ the system just hangs in OOM situation.
Surprisingly, this time OOM-killer is innocent ;) and finally I can reproduce
this more-or-less reliably just running
#include <stdlib.h>
#include <string.h>
int main(void)
{
for (;;) {
void *p = malloc(1024 * 1024);
memset(p, 0, 1024 * 1024);
}
}
in a loop on the otherwise idle system. 512m RAM, one CPU (but CONFIG_SMP=y),
no swap, and only one user-space process (apart from test-case above), /bin/sh
runnning as init with pid==1. I am attaching my .config just in case, but I
think the problem is not really specific to this configuration.
--------------------------------------------------------------------------------
It spins in __alloc_pages_slowpath() forever, __alloc_pages_may_oom() is never
called, it doesn't react to SIGKILL, etc.
This is because zone_reclaimable() is always true in shrink_zones(), and the
problem goes away if I comment out this code
if (global_reclaim(sc) &&
!reclaimable && zone_reclaimable(zone))
reclaimable = true;
in shrink_zones() which otherwise returns this "true" every time, and thus
__alloc_pages_slowpath() always sees did_some_progress != 0.
-------------------------------------------------------------------------------
I don't understand vmscan.c, and in fact I don't even understand NR_PAGES_SCANNED
counter... why it has to be atomic/per-cpu? It is always updated under ->lru_lock
except free_pcppages_bulk/free_one_page try to reset this counter. But note that
they both do
nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
if (nr_scanned)
__mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
and this doesn't look exactly right: zone_page_state() ignores the per-cpu
->vm_stat_diff[] counters (and we probably do not want for_each_online_cpu()
loop here). And I do not know if this is really bad or not, but note that if
I change calculate_normal_threshold() to return 0, the problem goes away too.
Oleg.
-------------------------------------------------------------------------------
# Automatically generated file; DO NOT EDIT.
# Linux/x86 4.6.0-rc7 Kernel Configuration
#
CONFIG_64BIT=y
CONFIG_X86_64=y
CONFIG_X86=y
CONFIG_INSTRUCTION_DECODER=y
CONFIG_PERF_EVENTS_INTEL_UNCORE=y
CONFIG_OUTPUT_FORMAT="elf64-x86-64"
CONFIG_ARCH_DEFCONFIG="arch/x86/configs/x86_64_defconfig"
CONFIG_LOCKDEP_SUPPORT=y
CONFIG_STACKTRACE_SUPPORT=y
CONFIG_MMU=y
CONFIG_ARCH_MMAP_RND_BITS_MIN=28
CONFIG_ARCH_MMAP_RND_BITS_MAX=32
CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MIN=8
CONFIG_ARCH_MMAP_RND_COMPAT_BITS_MAX=16
CONFIG_NEED_DMA_MAP_STATE=y
CONFIG_NEED_SG_DMA_LENGTH=y
CONFIG_GENERIC_BUG=y
CONFIG_GENERIC_BUG_RELATIVE_POINTERS=y
CONFIG_GENERIC_HWEIGHT=y
CONFIG_RWSEM_XCHGADD_ALGORITHM=y
CONFIG_GENERIC_CALIBRATE_DELAY=y
CONFIG_ARCH_HAS_CPU_RELAX=y
CONFIG_ARCH_HAS_CACHE_LINE_SIZE=y
CONFIG_HAVE_SETUP_PER_CPU_AREA=y
CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK=y
CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK=y
CONFIG_ARCH_HIBERNATION_POSSIBLE=y
CONFIG_ARCH_SUSPEND_POSSIBLE=y
CONFIG_ARCH_WANT_HUGE_PMD_SHARE=y
CONFIG_ARCH_WANT_GENERAL_HUGETLB=y
CONFIG_ZONE_DMA32=y
CONFIG_AUDIT_ARCH=y
CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING=y
CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC=y
CONFIG_X86_64_SMP=y
CONFIG_ARCH_HWEIGHT_CFLAGS="-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11"
CONFIG_ARCH_SUPPORTS_UPROBES=y
CONFIG_FIX_EARLYCON_MEM=y
CONFIG_DEBUG_RODATA=y
CONFIG_PGTABLE_LEVELS=4
CONFIG_DEFCONFIG_LIST="/lib/modules/$UNAME_RELEASE/.config"
CONFIG_IRQ_WORK=y
CONFIG_BUILDTIME_EXTABLE_SORT=y
#
# General setup
#
CONFIG_INIT_ENV_ARG_LIMIT=32
CONFIG_CROSS_COMPILE=""
# CONFIG_COMPILE_TEST is not set
CONFIG_LOCALVERSION=""
CONFIG_LOCALVERSION_AUTO=y
CONFIG_HAVE_KERNEL_GZIP=y
CONFIG_HAVE_KERNEL_BZIP2=y
CONFIG_HAVE_KERNEL_LZMA=y
CONFIG_HAVE_KERNEL_XZ=y
CONFIG_HAVE_KERNEL_LZO=y
CONFIG_HAVE_KERNEL_LZ4=y
CONFIG_KERNEL_GZIP=y
# CONFIG_KERNEL_BZIP2 is not set
# CONFIG_KERNEL_LZMA is not set
# CONFIG_KERNEL_XZ is not set
# CONFIG_KERNEL_LZO is not set
# CONFIG_KERNEL_LZ4 is not set
CONFIG_DEFAULT_HOSTNAME="(none)"
CONFIG_SWAP=y
CONFIG_SYSVIPC=y
CONFIG_SYSVIPC_SYSCTL=y
CONFIG_POSIX_MQUEUE=y
CONFIG_POSIX_MQUEUE_SYSCTL=y
# CONFIG_CROSS_MEMORY_ATTACH is not set
# CONFIG_FHANDLE is not set
# CONFIG_USELIB is not set
# CONFIG_AUDIT is not set
CONFIG_HAVE_ARCH_AUDITSYSCALL=y
#
# IRQ subsystem
#
CONFIG_GENERIC_IRQ_PROBE=y
CONFIG_GENERIC_IRQ_SHOW=y
CONFIG_GENERIC_PENDING_IRQ=y
CONFIG_IRQ_DOMAIN=y
CONFIG_IRQ_DOMAIN_HIERARCHY=y
CONFIG_GENERIC_MSI_IRQ=y
CONFIG_GENERIC_MSI_IRQ_DOMAIN=y
# CONFIG_IRQ_DOMAIN_DEBUG is not set
CONFIG_IRQ_FORCED_THREADING=y
CONFIG_SPARSE_IRQ=y
CONFIG_CLOCKSOURCE_WATCHDOG=y
CONFIG_ARCH_CLOCKSOURCE_DATA=y
CONFIG_CLOCKSOURCE_VALIDATE_LAST_CYCLE=y
CONFIG_GENERIC_TIME_VSYSCALL=y
CONFIG_GENERIC_CLOCKEVENTS=y
CONFIG_GENERIC_CLOCKEVENTS_BROADCAST=y
CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST=y
CONFIG_GENERIC_CMOS_UPDATE=y
#
# Timers subsystem
#
CONFIG_TICK_ONESHOT=y
CONFIG_NO_HZ_COMMON=y
# CONFIG_HZ_PERIODIC is not set
CONFIG_NO_HZ_IDLE=y
# CONFIG_NO_HZ_FULL is not set
CONFIG_NO_HZ=y
CONFIG_HIGH_RES_TIMERS=y
#
# CPU/Task time and stats accounting
#
CONFIG_TICK_CPU_ACCOUNTING=y
# CONFIG_VIRT_CPU_ACCOUNTING_GEN is not set
# CONFIG_IRQ_TIME_ACCOUNTING is not set
# CONFIG_BSD_PROCESS_ACCT is not set
# CONFIG_TASKSTATS is not set
#
# RCU Subsystem
#
CONFIG_PREEMPT_RCU=y
# CONFIG_RCU_EXPERT is not set
CONFIG_SRCU=y
# CONFIG_TASKS_RCU is not set
CONFIG_RCU_STALL_COMMON=y
# CONFIG_TREE_RCU_TRACE is not set
# CONFIG_RCU_EXPEDITE_BOOT is not set
CONFIG_BUILD_BIN2C=y
CONFIG_IKCONFIG=y
CONFIG_IKCONFIG_PROC=y
CONFIG_LOG_BUF_SHIFT=19
CONFIG_LOG_CPU_MAX_BUF_SHIFT=12
CONFIG_HAVE_UNSTABLE_SCHED_CLOCK=y
CONFIG_ARCH_SUPPORTS_NUMA_BALANCING=y
CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH=y
CONFIG_ARCH_SUPPORTS_INT128=y
CONFIG_CGROUPS=y
# CONFIG_MEMCG is not set
# CONFIG_BLK_CGROUP is not set
# CONFIG_CGROUP_SCHED is not set
CONFIG_CGROUP_PIDS=y
# CONFIG_CGROUP_FREEZER is not set
# CONFIG_CGROUP_HUGETLB is not set
# CONFIG_CPUSETS is not set
# CONFIG_CGROUP_DEVICE is not set
# CONFIG_CGROUP_CPUACCT is not set
CONFIG_CGROUP_PERF=y
# CONFIG_CGROUP_DEBUG is not set
CONFIG_CHECKPOINT_RESTORE=y
CONFIG_NAMESPACES=y
CONFIG_UTS_NS=y
CONFIG_IPC_NS=y
CONFIG_USER_NS=y
CONFIG_PID_NS=y
CONFIG_NET_NS=y
# CONFIG_SCHED_AUTOGROUP is not set
# CONFIG_SYSFS_DEPRECATED is not set
# CONFIG_RELAY is not set
CONFIG_BLK_DEV_INITRD=y
CONFIG_INITRAMFS_SOURCE=""
CONFIG_RD_GZIP=y
# CONFIG_RD_BZIP2 is not set
# CONFIG_RD_LZMA is not set
# CONFIG_RD_XZ is not set
# CONFIG_RD_LZO is not set
# CONFIG_RD_LZ4 is not set
# CONFIG_CC_OPTIMIZE_FOR_SIZE is not set
CONFIG_SYSCTL=y
CONFIG_ANON_INODES=y
CONFIG_HAVE_UID16=y
CONFIG_SYSCTL_EXCEPTION_TRACE=y
CONFIG_HAVE_PCSPKR_PLATFORM=y
CONFIG_BPF=y
CONFIG_EXPERT=y
CONFIG_UID16=y
CONFIG_MULTIUSER=y
# CONFIG_SGETMASK_SYSCALL is not set
# CONFIG_SYSFS_SYSCALL is not set
CONFIG_SYSCTL_SYSCALL=y
CONFIG_KALLSYMS=y
CONFIG_KALLSYMS_ALL=y
CONFIG_KALLSYMS_ABSOLUTE_PERCPU=y
CONFIG_KALLSYMS_BASE_RELATIVE=y
CONFIG_PRINTK=y
CONFIG_BUG=y
CONFIG_ELF_CORE=y
# CONFIG_PCSPKR_PLATFORM is not set
CONFIG_BASE_FULL=y
CONFIG_FUTEX=y
CONFIG_EPOLL=y
CONFIG_SIGNALFD=y
CONFIG_TIMERFD=y
CONFIG_EVENTFD=y
# CONFIG_BPF_SYSCALL is not set
CONFIG_SHMEM=y
CONFIG_AIO=y
CONFIG_ADVISE_SYSCALLS=y
CONFIG_USERFAULTFD=y
# CONFIG_PCI_QUIRKS is not set
CONFIG_MEMBARRIER=y
# CONFIG_EMBEDDED is not set
CONFIG_HAVE_PERF_EVENTS=y
#
# Kernel Performance Events And Counters
#
CONFIG_PERF_EVENTS=y
# CONFIG_DEBUG_PERF_USE_VMALLOC is not set
CONFIG_VM_EVENT_COUNTERS=y
CONFIG_SLUB_DEBUG=y
# CONFIG_COMPAT_BRK is not set
# CONFIG_SLAB is not set
CONFIG_SLUB=y
# CONFIG_SLOB is not set
# CONFIG_SLUB_CPU_PARTIAL is not set
# CONFIG_SYSTEM_DATA_VERIFICATION is not set
# CONFIG_PROFILING is not set
CONFIG_TRACEPOINTS=y
CONFIG_HAVE_OPROFILE=y
CONFIG_OPROFILE_NMI_TIMER=y
CONFIG_KPROBES=y
CONFIG_JUMP_LABEL=y
# CONFIG_STATIC_KEYS_SELFTEST is not set
CONFIG_KPROBES_ON_FTRACE=y
CONFIG_UPROBES=y
# CONFIG_HAVE_64BIT_ALIGNED_ACCESS is not set
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y
CONFIG_ARCH_USE_BUILTIN_BSWAP=y
CONFIG_KRETPROBES=y
CONFIG_HAVE_IOREMAP_PROT=y
CONFIG_HAVE_KPROBES=y
CONFIG_HAVE_KRETPROBES=y
CONFIG_HAVE_OPTPROBES=y
CONFIG_HAVE_KPROBES_ON_FTRACE=y
CONFIG_HAVE_ARCH_TRACEHOOK=y
CONFIG_HAVE_DMA_CONTIGUOUS=y
CONFIG_GENERIC_SMP_IDLE_THREAD=y
CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT=y
CONFIG_HAVE_REGS_AND_STACK_ACCESS_API=y
CONFIG_HAVE_DMA_API_DEBUG=y
CONFIG_HAVE_HW_BREAKPOINT=y
CONFIG_HAVE_MIXED_BREAKPOINTS_REGS=y
CONFIG_HAVE_USER_RETURN_NOTIFIER=y
CONFIG_HAVE_PERF_EVENTS_NMI=y
CONFIG_HAVE_PERF_REGS=y
CONFIG_HAVE_PERF_USER_STACK_DUMP=y
CONFIG_HAVE_ARCH_JUMP_LABEL=y
CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG=y
CONFIG_HAVE_ALIGNED_STRUCT_PAGE=y
CONFIG_HAVE_CMPXCHG_LOCAL=y
CONFIG_HAVE_CMPXCHG_DOUBLE=y
CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION=y
CONFIG_ARCH_WANT_OLD_COMPAT_IPC=y
CONFIG_HAVE_ARCH_SECCOMP_FILTER=y
CONFIG_SECCOMP_FILTER=y
CONFIG_HAVE_CC_STACKPROTECTOR=y
# CONFIG_CC_STACKPROTECTOR is not set
CONFIG_CC_STACKPROTECTOR_NONE=y
# CONFIG_CC_STACKPROTECTOR_REGULAR is not set
# CONFIG_CC_STACKPROTECTOR_STRONG is not set
CONFIG_HAVE_CONTEXT_TRACKING=y
CONFIG_HAVE_VIRT_CPU_ACCOUNTING_GEN=y
CONFIG_HAVE_IRQ_TIME_ACCOUNTING=y
CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE=y
CONFIG_HAVE_ARCH_HUGE_VMAP=y
CONFIG_HAVE_ARCH_SOFT_DIRTY=y
CONFIG_MODULES_USE_ELF_RELA=y
CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK=y
CONFIG_ARCH_HAS_ELF_RANDOMIZE=y
CONFIG_HAVE_ARCH_MMAP_RND_BITS=y
CONFIG_ARCH_MMAP_RND_BITS=28
CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS=y
CONFIG_ARCH_MMAP_RND_COMPAT_BITS=8
CONFIG_HAVE_COPY_THREAD_TLS=y
CONFIG_HAVE_STACK_VALIDATION=y
CONFIG_OLD_SIGSUSPEND3=y
CONFIG_COMPAT_OLD_SIGACTION=y
#
# GCOV-based kernel profiling
#
# CONFIG_GCOV_KERNEL is not set
CONFIG_ARCH_HAS_GCOV_PROFILE_ALL=y
# CONFIG_HAVE_GENERIC_DMA_COHERENT is not set
CONFIG_SLABINFO=y
CONFIG_RT_MUTEXES=y
CONFIG_BASE_SMALL=0
CONFIG_MODULES=y
CONFIG_MODULE_FORCE_LOAD=y
CONFIG_MODULE_UNLOAD=y
CONFIG_MODULE_FORCE_UNLOAD=y
# CONFIG_MODVERSIONS is not set
# CONFIG_MODULE_SRCVERSION_ALL is not set
# CONFIG_MODULE_SIG is not set
# CONFIG_MODULE_COMPRESS is not set
CONFIG_MODULES_TREE_LOOKUP=y
CONFIG_BLOCK=y
# CONFIG_BLK_DEV_BSG is not set
# CONFIG_BLK_DEV_BSGLIB is not set
# CONFIG_BLK_DEV_INTEGRITY is not set
# CONFIG_BLK_CMDLINE_PARSER is not set
#
# Partition Types
#
# CONFIG_PARTITION_ADVANCED is not set
CONFIG_MSDOS_PARTITION=y
CONFIG_EFI_PARTITION=y
CONFIG_BLOCK_COMPAT=y
#
# IO Schedulers
#
CONFIG_IOSCHED_NOOP=y
CONFIG_IOSCHED_DEADLINE=y
CONFIG_IOSCHED_CFQ=y
# CONFIG_DEFAULT_DEADLINE is not set
CONFIG_DEFAULT_CFQ=y
# CONFIG_DEFAULT_NOOP is not set
CONFIG_DEFAULT_IOSCHED="cfq"
CONFIG_UNINLINE_SPIN_UNLOCK=y
CONFIG_ARCH_SUPPORTS_ATOMIC_RMW=y
CONFIG_RWSEM_SPIN_ON_OWNER=y
CONFIG_LOCK_SPIN_ON_OWNER=y
CONFIG_ARCH_USE_QUEUED_SPINLOCKS=y
CONFIG_QUEUED_SPINLOCKS=y
CONFIG_ARCH_USE_QUEUED_RWLOCKS=y
CONFIG_QUEUED_RWLOCKS=y
# CONFIG_FREEZER is not set
#
# Processor type and features
#
CONFIG_ZONE_DMA=y
CONFIG_SMP=y
CONFIG_X86_FEATURE_NAMES=y
CONFIG_X86_FAST_FEATURE_TESTS=y
# CONFIG_X86_MPPARSE is not set
# CONFIG_GOLDFISH is not set
# CONFIG_X86_EXTENDED_PLATFORM is not set
# CONFIG_X86_INTEL_LPSS is not set
# CONFIG_X86_AMD_PLATFORM_DEVICE is not set
# CONFIG_IOSF_MBI is not set
# CONFIG_SCHED_OMIT_FRAME_POINTER is not set
# CONFIG_HYPERVISOR_GUEST is not set
CONFIG_NO_BOOTMEM=y
# CONFIG_MK8 is not set
# CONFIG_MPSC is not set
# CONFIG_MCORE2 is not set
# CONFIG_MATOM is not set
CONFIG_GENERIC_CPU=y
CONFIG_X86_INTERNODE_CACHE_SHIFT=6
CONFIG_X86_L1_CACHE_SHIFT=6
CONFIG_X86_TSC=y
CONFIG_X86_CMPXCHG64=y
CONFIG_X86_CMOV=y
CONFIG_X86_MINIMUM_CPU_FAMILY=64
CONFIG_X86_DEBUGCTLMSR=y
# CONFIG_PROCESSOR_SELECT is not set
CONFIG_CPU_SUP_INTEL=y
CONFIG_CPU_SUP_AMD=y
CONFIG_CPU_SUP_CENTAUR=y
CONFIG_HPET_TIMER=y
# CONFIG_DMI is not set
# CONFIG_GART_IOMMU is not set
# CONFIG_CALGARY_IOMMU is not set
CONFIG_SWIOTLB=y
CONFIG_IOMMU_HELPER=y
# CONFIG_MAXSMP is not set
CONFIG_NR_CPUS=16
CONFIG_SCHED_SMT=y
CONFIG_SCHED_MC=y
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
CONFIG_PREEMPT_COUNT=y
CONFIG_X86_LOCAL_APIC=y
CONFIG_X86_IO_APIC=y
# CONFIG_X86_REROUTE_FOR_BROKEN_BOOT_IRQS is not set
# CONFIG_X86_MCE is not set
# CONFIG_VM86 is not set
CONFIG_X86_VSYSCALL_EMULATION=y
# CONFIG_I8K is not set
# CONFIG_MICROCODE is not set
# CONFIG_PERF_EVENTS_AMD_POWER is not set
# CONFIG_X86_MSR is not set
# CONFIG_X86_CPUID is not set
CONFIG_ARCH_PHYS_ADDR_T_64BIT=y
CONFIG_ARCH_DMA_ADDR_T_64BIT=y
CONFIG_X86_DIRECT_GBPAGES=y
# CONFIG_NUMA is not set
CONFIG_ARCH_SPARSEMEM_ENABLE=y
CONFIG_ARCH_SPARSEMEM_DEFAULT=y
CONFIG_ARCH_SELECT_MEMORY_MODEL=y
CONFIG_ARCH_PROC_KCORE_TEXT=y
CONFIG_ILLEGAL_POINTER_VALUE=0xdead000000000000
CONFIG_SELECT_MEMORY_MODEL=y
CONFIG_SPARSEMEM_MANUAL=y
CONFIG_SPARSEMEM=y
CONFIG_HAVE_MEMORY_PRESENT=y
CONFIG_SPARSEMEM_EXTREME=y
CONFIG_SPARSEMEM_VMEMMAP_ENABLE=y
CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER=y
CONFIG_SPARSEMEM_VMEMMAP=y
CONFIG_HAVE_MEMBLOCK=y
CONFIG_HAVE_MEMBLOCK_NODE_MAP=y
CONFIG_ARCH_DISCARD_MEMBLOCK=y
# CONFIG_HAVE_BOOTMEM_INFO_NODE is not set
# CONFIG_MEMORY_HOTPLUG is not set
CONFIG_SPLIT_PTLOCK_CPUS=4
CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK=y
CONFIG_MEMORY_BALLOON=y
# CONFIG_COMPACTION is not set
CONFIG_PHYS_ADDR_T_64BIT=y
CONFIG_ZONE_DMA_FLAG=1
CONFIG_BOUNCE=y
CONFIG_VIRT_TO_BUS=y
# CONFIG_KSM is not set
CONFIG_DEFAULT_MMAP_MIN_ADDR=4096
# CONFIG_TRANSPARENT_HUGEPAGE is not set
# CONFIG_CLEANCACHE is not set
# CONFIG_FRONTSWAP is not set
# CONFIG_CMA is not set
CONFIG_MEM_SOFT_DIRTY=y
# CONFIG_ZPOOL is not set
# CONFIG_ZBUD is not set
# CONFIG_ZSMALLOC is not set
CONFIG_GENERIC_EARLY_IOREMAP=y
CONFIG_ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT=y
# CONFIG_IDLE_PAGE_TRACKING is not set
# CONFIG_X86_PMEM_LEGACY is not set
# CONFIG_X86_CHECK_BIOS_CORRUPTION is not set
CONFIG_X86_RESERVE_LOW=64
CONFIG_MTRR=y
# CONFIG_MTRR_SANITIZER is not set
CONFIG_X86_PAT=y
CONFIG_ARCH_USES_PG_UNCACHED=y
# CONFIG_ARCH_RANDOM is not set
# CONFIG_X86_SMAP is not set
# CONFIG_X86_INTEL_MPX is not set
# CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS is not set
# CONFIG_EFI is not set
CONFIG_SECCOMP=y
# CONFIG_HZ_100 is not set
# CONFIG_HZ_250 is not set
CONFIG_HZ_300=y
# CONFIG_HZ_1000 is not set
CONFIG_HZ=300
CONFIG_SCHED_HRTICK=y
# CONFIG_KEXEC is not set
# CONFIG_CRASH_DUMP is not set
CONFIG_PHYSICAL_START=0x1000000
# CONFIG_RELOCATABLE is not set
CONFIG_PHYSICAL_ALIGN=0x1000000
CONFIG_HOTPLUG_CPU=y
# CONFIG_BOOTPARAM_HOTPLUG_CPU0 is not set
# CONFIG_DEBUG_HOTPLUG_CPU0 is not set
# CONFIG_COMPAT_VDSO is not set
CONFIG_LEGACY_VSYSCALL_NATIVE=y
# CONFIG_LEGACY_VSYSCALL_EMULATE is not set
# CONFIG_LEGACY_VSYSCALL_NONE is not set
# CONFIG_CMDLINE_BOOL is not set
# CONFIG_MODIFY_LDT_SYSCALL is not set
CONFIG_HAVE_LIVEPATCH=y
# CONFIG_LIVEPATCH is not set
CONFIG_ARCH_ENABLE_MEMORY_HOTPLUG=y
#
# Power management and ACPI options
#
# CONFIG_SUSPEND is not set
# CONFIG_HIBERNATION is not set
# CONFIG_PM is not set
CONFIG_ACPI=y
CONFIG_ACPI_LEGACY_TABLES_LOOKUP=y
CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC=y
CONFIG_ACPI_SYSTEM_POWER_STATES_SUPPORT=y
# CONFIG_ACPI_DEBUGGER is not set
# CONFIG_ACPI_PROCFS_POWER is not set
CONFIG_ACPI_REV_OVERRIDE_POSSIBLE=y
# CONFIG_ACPI_EC_DEBUGFS is not set
# CONFIG_ACPI_AC is not set
# CONFIG_ACPI_BATTERY is not set
# CONFIG_ACPI_BUTTON is not set
# CONFIG_ACPI_DOCK is not set
# CONFIG_ACPI_PROCESSOR is not set
# CONFIG_ACPI_CUSTOM_DSDT is not set
# CONFIG_ACPI_INITRD_TABLE_OVERRIDE is not set
# CONFIG_ACPI_DEBUG is not set
# CONFIG_ACPI_PCI_SLOT is not set
CONFIG_X86_PM_TIMER=y
# CONFIG_ACPI_CONTAINER is not set
CONFIG_ACPI_HOTPLUG_IOAPIC=y
# CONFIG_ACPI_SBS is not set
# CONFIG_ACPI_HED is not set
# CONFIG_ACPI_CUSTOM_METHOD is not set
# CONFIG_ACPI_REDUCED_HARDWARE_ONLY is not set
# CONFIG_ACPI_NFIT is not set
CONFIG_HAVE_ACPI_APEI=y
CONFIG_HAVE_ACPI_APEI_NMI=y
# CONFIG_ACPI_APEI is not set
# CONFIG_PMIC_OPREGION is not set
# CONFIG_SFI is not set
#
# CPU Frequency scaling
#
# CONFIG_CPU_FREQ is not set
#
# CPU Idle
#
CONFIG_CPU_IDLE=y
CONFIG_CPU_IDLE_GOV_LADDER=y
CONFIG_CPU_IDLE_GOV_MENU=y
# CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED is not set
# CONFIG_INTEL_IDLE is not set
#
# Memory power savings
#
# CONFIG_I7300_IDLE is not set
#
# Bus options (PCI etc.)
#
CONFIG_PCI=y
CONFIG_PCI_DIRECT=y
# CONFIG_PCI_MMCONFIG is not set
CONFIG_PCI_DOMAINS=y
# CONFIG_PCI_CNB20LE_QUIRK is not set
CONFIG_PCIEPORTBUS=y
# CONFIG_PCIEAER is not set
# CONFIG_PCIEASPM is not set
CONFIG_PCI_BUS_ADDR_T_64BIT=y
CONFIG_PCI_MSI=y
CONFIG_PCI_MSI_IRQ_DOMAIN=y
# CONFIG_PCI_DEBUG is not set
# CONFIG_PCI_REALLOC_ENABLE_AUTO is not set
# CONFIG_PCI_STUB is not set
# CONFIG_HT_IRQ is not set
# CONFIG_PCI_IOV is not set
# CONFIG_PCI_PRI is not set
# CONFIG_PCI_PASID is not set
CONFIG_PCI_LABEL=y
# CONFIG_HOTPLUG_PCI is not set
#
# PCI host controller drivers
#
# CONFIG_PCIE_DW_PLAT is not set
# CONFIG_ISA_DMA_API is not set
CONFIG_AMD_NB=y
# CONFIG_PCCARD is not set
# CONFIG_RAPIDIO is not set
# CONFIG_X86_SYSFB is not set
#
# Executable file formats / Emulations
#
CONFIG_BINFMT_ELF=y
CONFIG_COMPAT_BINFMT_ELF=y
# CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
CONFIG_BINFMT_SCRIPT=y
# CONFIG_HAVE_AOUT is not set
# CONFIG_BINFMT_MISC is not set
CONFIG_COREDUMP=y
CONFIG_IA32_EMULATION=y
# CONFIG_IA32_AOUT is not set
# CONFIG_X86_X32 is not set
CONFIG_COMPAT=y
CONFIG_COMPAT_FOR_U64_ALIGNMENT=y
CONFIG_SYSVIPC_COMPAT=y
CONFIG_X86_DEV_DMA_OPS=y
CONFIG_PMC_ATOM=y
# CONFIG_VMD is not set
CONFIG_NET=y
#
# Networking options
#
CONFIG_PACKET=y
# CONFIG_PACKET_DIAG is not set
CONFIG_UNIX=y
# CONFIG_UNIX_DIAG is not set
# CONFIG_XFRM_USER is not set
# CONFIG_NET_KEY is not set
CONFIG_INET=y
CONFIG_IP_MULTICAST=y
CONFIG_IP_ADVANCED_ROUTER=y
# CONFIG_IP_FIB_TRIE_STATS is not set
CONFIG_IP_MULTIPLE_TABLES=y
CONFIG_IP_ROUTE_MULTIPATH=y
CONFIG_IP_ROUTE_VERBOSE=y
# CONFIG_IP_PNP is not set
# CONFIG_NET_IPIP is not set
# CONFIG_NET_IPGRE_DEMUX is not set
# CONFIG_NET_IP_TUNNEL is not set
CONFIG_IP_MROUTE=y
# CONFIG_IP_MROUTE_MULTIPLE_TABLES is not set
CONFIG_IP_PIMSM_V1=y
CONFIG_IP_PIMSM_V2=y
CONFIG_SYN_COOKIES=y
# CONFIG_NET_UDP_TUNNEL is not set
# CONFIG_NET_FOU is not set
# CONFIG_INET_AH is not set
# CONFIG_INET_ESP is not set
# CONFIG_INET_IPCOMP is not set
# CONFIG_INET_XFRM_TUNNEL is not set
# CONFIG_INET_TUNNEL is not set
# CONFIG_INET_XFRM_MODE_TRANSPORT is not set
# CONFIG_INET_XFRM_MODE_TUNNEL is not set
# CONFIG_INET_XFRM_MODE_BEET is not set
CONFIG_INET_DIAG=y
CONFIG_INET_TCP_DIAG=y
# CONFIG_INET_UDP_DIAG is not set
# CONFIG_INET_DIAG_DESTROY is not set
# CONFIG_TCP_CONG_ADVANCED is not set
CONFIG_TCP_CONG_CUBIC=y
CONFIG_DEFAULT_TCP_CONG="cubic"
# CONFIG_TCP_MD5SIG is not set
# CONFIG_IPV6 is not set
CONFIG_NETWORK_SECMARK=y
# CONFIG_NET_PTP_CLASSIFY is not set
# CONFIG_NETWORK_PHY_TIMESTAMPING is not set
CONFIG_NETFILTER=y
# CONFIG_NETFILTER_DEBUG is not set
CONFIG_NETFILTER_ADVANCED=y
#
# Core Netfilter Configuration
#
# CONFIG_NETFILTER_INGRESS is not set
# CONFIG_NETFILTER_NETLINK_ACCT is not set
# CONFIG_NETFILTER_NETLINK_QUEUE is not set
# CONFIG_NETFILTER_NETLINK_LOG is not set
# CONFIG_NF_CONNTRACK is not set
# CONFIG_NF_TABLES is not set
# CONFIG_NETFILTER_XTABLES is not set
# CONFIG_IP_SET is not set
# CONFIG_IP_VS is not set
#
# IP: Netfilter Configuration
#
# CONFIG_NF_DEFRAG_IPV4 is not set
# CONFIG_NF_DUP_IPV4 is not set
# CONFIG_NF_LOG_ARP is not set
# CONFIG_NF_LOG_IPV4 is not set
# CONFIG_NF_REJECT_IPV4 is not set
# CONFIG_IP_NF_IPTABLES is not set
# CONFIG_IP_NF_ARPTABLES is not set
# CONFIG_IP_DCCP is not set
# CONFIG_IP_SCTP is not set
# CONFIG_RDS is not set
# CONFIG_TIPC is not set
# CONFIG_ATM is not set
# CONFIG_L2TP is not set
# CONFIG_BRIDGE is not set
CONFIG_HAVE_NET_DSA=y
# CONFIG_VLAN_8021Q is not set
# CONFIG_DECNET is not set
# CONFIG_LLC2 is not set
# CONFIG_IPX is not set
# CONFIG_ATALK is not set
# CONFIG_X25 is not set
# CONFIG_LAPB is not set
# CONFIG_PHONET is not set
# CONFIG_IEEE802154 is not set
CONFIG_NET_SCHED=y
#
# Queueing/Scheduling
#
# CONFIG_NET_SCH_CBQ is not set
# CONFIG_NET_SCH_HTB is not set
# CONFIG_NET_SCH_HFSC is not set
# CONFIG_NET_SCH_PRIO is not set
# CONFIG_NET_SCH_MULTIQ is not set
# CONFIG_NET_SCH_RED is not set
# CONFIG_NET_SCH_SFB is not set
# CONFIG_NET_SCH_SFQ is not set
# CONFIG_NET_SCH_TEQL is not set
# CONFIG_NET_SCH_TBF is not set
# CONFIG_NET_SCH_GRED is not set
# CONFIG_NET_SCH_DSMARK is not set
# CONFIG_NET_SCH_NETEM is not set
# CONFIG_NET_SCH_DRR is not set
# CONFIG_NET_SCH_MQPRIO is not set
# CONFIG_NET_SCH_CHOKE is not set
# CONFIG_NET_SCH_QFQ is not set
# CONFIG_NET_SCH_CODEL is not set
# CONFIG_NET_SCH_FQ_CODEL is not set
# CONFIG_NET_SCH_FQ is not set
# CONFIG_NET_SCH_HHF is not set
# CONFIG_NET_SCH_PIE is not set
# CONFIG_NET_SCH_INGRESS is not set
# CONFIG_NET_SCH_PLUG is not set
#
# Classification
#
# CONFIG_NET_CLS_BASIC is not set
# CONFIG_NET_CLS_TCINDEX is not set
# CONFIG_NET_CLS_ROUTE4 is not set
# CONFIG_NET_CLS_FW is not set
# CONFIG_NET_CLS_U32 is not set
# CONFIG_NET_CLS_RSVP is not set
# CONFIG_NET_CLS_RSVP6 is not set
# CONFIG_NET_CLS_FLOW is not set
# CONFIG_NET_CLS_CGROUP is not set
# CONFIG_NET_CLS_BPF is not set
# CONFIG_NET_CLS_FLOWER is not set
# CONFIG_NET_EMATCH is not set
CONFIG_NET_CLS_ACT=y
# CONFIG_NET_ACT_POLICE is not set
# CONFIG_NET_ACT_GACT is not set
# CONFIG_NET_ACT_MIRRED is not set
# CONFIG_NET_ACT_NAT is not set
# CONFIG_NET_ACT_PEDIT is not set
# CONFIG_NET_ACT_SIMP is not set
# CONFIG_NET_ACT_SKBEDIT is not set
# CONFIG_NET_ACT_CSUM is not set
# CONFIG_NET_ACT_VLAN is not set
# CONFIG_NET_ACT_BPF is not set
# CONFIG_NET_ACT_IFE is not set
CONFIG_NET_SCH_FIFO=y
# CONFIG_DCB is not set
# CONFIG_BATMAN_ADV is not set
# CONFIG_OPENVSWITCH is not set
# CONFIG_VSOCKETS is not set
# CONFIG_NETLINK_DIAG is not set
# CONFIG_MPLS is not set
# CONFIG_HSR is not set
# CONFIG_NET_SWITCHDEV is not set
# CONFIG_NET_L3_MASTER_DEV is not set
CONFIG_RPS=y
CONFIG_RFS_ACCEL=y
CONFIG_XPS=y
# CONFIG_SOCK_CGROUP_DATA is not set
# CONFIG_CGROUP_NET_PRIO is not set
# CONFIG_CGROUP_NET_CLASSID is not set
CONFIG_NET_RX_BUSY_POLL=y
CONFIG_BQL=y
# CONFIG_BPF_JIT is not set
CONFIG_NET_FLOW_LIMIT=y
#
# Network testing
#
# CONFIG_NET_PKTGEN is not set
# CONFIG_NET_TCPPROBE is not set
# CONFIG_NET_DROP_MONITOR is not set
# CONFIG_HAMRADIO is not set
# CONFIG_CAN is not set
# CONFIG_IRDA is not set
# CONFIG_BT is not set
# CONFIG_AF_RXRPC is not set
# CONFIG_AF_KCM is not set
CONFIG_FIB_RULES=y
# CONFIG_WIRELESS is not set
# CONFIG_WIMAX is not set
# CONFIG_RFKILL is not set
CONFIG_NET_9P=y
CONFIG_NET_9P_VIRTIO=y
# CONFIG_NET_9P_DEBUG is not set
# CONFIG_CAIF is not set
# CONFIG_CEPH_LIB is not set
# CONFIG_NFC is not set
# CONFIG_LWTUNNEL is not set
# CONFIG_DST_CACHE is not set
# CONFIG_NET_DEVLINK is not set
CONFIG_MAY_USE_DEVLINK=y
CONFIG_HAVE_BPF_JIT=y
#
# Device Drivers
#
#
# Generic Driver Options
#
# CONFIG_UEVENT_HELPER is not set
CONFIG_DEVTMPFS=y
# CONFIG_DEVTMPFS_MOUNT is not set
CONFIG_STANDALONE=y
CONFIG_PREVENT_FIRMWARE_BUILD=y
CONFIG_FW_LOADER=y
CONFIG_FIRMWARE_IN_KERNEL=y
CONFIG_EXTRA_FIRMWARE=""
# CONFIG_FW_LOADER_USER_HELPER_FALLBACK is not set
# CONFIG_ALLOW_DEV_COREDUMP is not set
# CONFIG_DEBUG_DRIVER is not set
# CONFIG_DEBUG_DEVRES is not set
# CONFIG_SYS_HYPERVISOR is not set
# CONFIG_GENERIC_CPU_DEVICES is not set
CONFIG_GENERIC_CPU_AUTOPROBE=y
# CONFIG_DMA_SHARED_BUFFER is not set
#
# Bus devices
#
# CONFIG_CONNECTOR is not set
# CONFIG_MTD is not set
# CONFIG_OF is not set
CONFIG_ARCH_MIGHT_HAVE_PC_PARPORT=y
# CONFIG_PARPORT is not set
CONFIG_PNP=y
# CONFIG_PNP_DEBUG_MESSAGES is not set
#
# Protocols
#
CONFIG_PNPACPI=y
CONFIG_BLK_DEV=y
# CONFIG_BLK_DEV_NULL_BLK is not set
# CONFIG_BLK_DEV_PCIESSD_MTIP32XX is not set
# CONFIG_BLK_CPQ_CISS_DA is not set
# CONFIG_BLK_DEV_DAC960 is not set
# CONFIG_BLK_DEV_UMEM is not set
# CONFIG_BLK_DEV_COW_COMMON is not set
CONFIG_BLK_DEV_LOOP=y
CONFIG_BLK_DEV_LOOP_MIN_COUNT=8
# CONFIG_BLK_DEV_CRYPTOLOOP is not set
# CONFIG_BLK_DEV_DRBD is not set
# CONFIG_BLK_DEV_NBD is not set
# CONFIG_BLK_DEV_SKD is not set
# CONFIG_BLK_DEV_SX8 is not set
# CONFIG_BLK_DEV_RAM is not set
# CONFIG_CDROM_PKTCDVD is not set
# CONFIG_ATA_OVER_ETH is not set
CONFIG_VIRTIO_BLK=y
# CONFIG_BLK_DEV_HD is not set
# CONFIG_BLK_DEV_RBD is not set
# CONFIG_BLK_DEV_RSXX is not set
# CONFIG_BLK_DEV_NVME is not set
#
# Misc devices
#
# CONFIG_SENSORS_LIS3LV02D is not set
# CONFIG_DUMMY_IRQ is not set
# CONFIG_IBM_ASM is not set
# CONFIG_PHANTOM is not set
# CONFIG_SGI_IOC4 is not set
# CONFIG_TIFM_CORE is not set
# CONFIG_ENCLOSURE_SERVICES is not set
# CONFIG_HP_ILO is not set
# CONFIG_SRAM is not set
# CONFIG_C2PORT is not set
#
# EEPROM support
#
# CONFIG_EEPROM_93CX6 is not set
# CONFIG_CB710_CORE is not set
#
# Texas Instruments shared transport line discipline
#
#
# Altera FPGA firmware download module
#
# CONFIG_INTEL_MEI is not set
# CONFIG_INTEL_MEI_ME is not set
# CONFIG_INTEL_MEI_TXE is not set
# CONFIG_VMWARE_VMCI is not set
#
# Intel MIC Bus Driver
#
# CONFIG_INTEL_MIC_BUS is not set
#
# SCIF Bus Driver
#
# CONFIG_SCIF_BUS is not set
#
# VOP Bus Driver
#
# CONFIG_VOP_BUS is not set
#
# Intel MIC Host Driver
#
#
# Intel MIC Card Driver
#
#
# SCIF Driver
#
#
# Intel MIC Coprocessor State Management (COSM) Drivers
#
#
# VOP Driver
#
# CONFIG_GENWQE is not set
# CONFIG_ECHO is not set
# CONFIG_CXL_BASE is not set
# CONFIG_CXL_KERNEL_API is not set
# CONFIG_CXL_EEH is not set
CONFIG_HAVE_IDE=y
# CONFIG_IDE is not set
#
# SCSI device support
#
CONFIG_SCSI_MOD=y
# CONFIG_RAID_ATTRS is not set
# CONFIG_SCSI is not set
# CONFIG_SCSI_DMA is not set
# CONFIG_SCSI_NETLINK is not set
# CONFIG_ATA is not set
# CONFIG_MD is not set
# CONFIG_FUSION is not set
#
# IEEE 1394 (FireWire) support
#
# CONFIG_FIREWIRE is not set
# CONFIG_FIREWIRE_NOSY is not set
# CONFIG_MACINTOSH_DRIVERS is not set
CONFIG_NETDEVICES=y
CONFIG_NET_CORE=y
# CONFIG_BONDING is not set
# CONFIG_DUMMY is not set
# CONFIG_EQUALIZER is not set
# CONFIG_IFB is not set
# CONFIG_NET_TEAM is not set
# CONFIG_MACVLAN is not set
# CONFIG_VXLAN is not set
# CONFIG_MACSEC is not set
# CONFIG_NETCONSOLE is not set
# CONFIG_NETPOLL is not set
# CONFIG_NET_POLL_CONTROLLER is not set
# CONFIG_TUN is not set
# CONFIG_TUN_VNET_CROSS_LE is not set
# CONFIG_VETH is not set
CONFIG_VIRTIO_NET=y
# CONFIG_NLMON is not set
# CONFIG_ARCNET is not set
#
# CAIF transport drivers
#
# CONFIG_VHOST_NET is not set
# CONFIG_VHOST_CROSS_ENDIAN_LEGACY is not set
#
# Distributed Switch Architecture drivers
#
# CONFIG_NET_DSA_MV88E6XXX is not set
# CONFIG_NET_DSA_MV88E6XXX_NEED_PPU is not set
# CONFIG_ETHERNET is not set
# CONFIG_FDDI is not set
# CONFIG_HIPPI is not set
# CONFIG_NET_SB1000 is not set
# CONFIG_PHYLIB is not set
# CONFIG_PPP is not set
# CONFIG_SLIP is not set
#
# Host-side USB support is needed for USB Network Adapter support
#
# CONFIG_WLAN is not set
#
# Enable WiMAX (Networking options) to see the WiMAX drivers
#
# CONFIG_WAN is not set
# CONFIG_VMXNET3 is not set
# CONFIG_FUJITSU_ES is not set
# CONFIG_ISDN is not set
# CONFIG_NVM is not set
#
# Input device support
#
CONFIG_INPUT=y
# CONFIG_INPUT_FF_MEMLESS is not set
# CONFIG_INPUT_POLLDEV is not set
# CONFIG_INPUT_SPARSEKMAP is not set
# CONFIG_INPUT_MATRIXKMAP is not set
#
# Userland interfaces
#
# CONFIG_INPUT_MOUSEDEV is not set
# CONFIG_INPUT_JOYDEV is not set
# CONFIG_INPUT_EVDEV is not set
# CONFIG_INPUT_EVBUG is not set
#
# Input Device Drivers
#
# CONFIG_INPUT_KEYBOARD is not set
# CONFIG_INPUT_MOUSE is not set
# CONFIG_INPUT_JOYSTICK is not set
# CONFIG_INPUT_TABLET is not set
# CONFIG_INPUT_TOUCHSCREEN is not set
# CONFIG_INPUT_MISC is not set
# CONFIG_RMI4_CORE is not set
#
# Hardware I/O ports
#
# CONFIG_SERIO is not set
CONFIG_ARCH_MIGHT_HAVE_PC_SERIO=y
# CONFIG_GAMEPORT is not set
#
# Character devices
#
CONFIG_TTY=y
# CONFIG_VT is not set
CONFIG_UNIX98_PTYS=y
# CONFIG_DEVPTS_MULTIPLE_INSTANCES is not set
# CONFIG_LEGACY_PTYS is not set
# CONFIG_SERIAL_NONSTANDARD is not set
# CONFIG_NOZOMI is not set
# CONFIG_N_GSM is not set
# CONFIG_TRACE_SINK is not set
CONFIG_DEVMEM=y
# CONFIG_DEVKMEM is not set
#
# Serial drivers
#
CONFIG_SERIAL_EARLYCON=y
CONFIG_SERIAL_8250=y
# CONFIG_SERIAL_8250_DEPRECATED_OPTIONS is not set
# CONFIG_SERIAL_8250_PNP is not set
CONFIG_SERIAL_8250_CONSOLE=y
# CONFIG_SERIAL_8250_PCI is not set
CONFIG_SERIAL_8250_NR_UARTS=4
CONFIG_SERIAL_8250_RUNTIME_UARTS=4
# CONFIG_SERIAL_8250_EXTENDED is not set
# CONFIG_SERIAL_8250_FSL is not set
# CONFIG_SERIAL_8250_DW is not set
# CONFIG_SERIAL_8250_RT288X is not set
# CONFIG_SERIAL_8250_FINTEK is not set
# CONFIG_SERIAL_8250_MID is not set
# CONFIG_SERIAL_8250_MOXA is not set
#
# Non-8250 serial port support
#
# CONFIG_SERIAL_UARTLITE is not set
CONFIG_SERIAL_CORE=y
CONFIG_SERIAL_CORE_CONSOLE=y
# CONFIG_SERIAL_JSM is not set
# CONFIG_SERIAL_SCCNXP is not set
# CONFIG_SERIAL_ALTERA_JTAGUART is not set
# CONFIG_SERIAL_ALTERA_UART is not set
# CONFIG_SERIAL_ARC is not set
# CONFIG_SERIAL_RP2 is not set
# CONFIG_SERIAL_FSL_LPUART is not set
# CONFIG_SERIAL_MVEBU_UART is not set
# CONFIG_TTY_PRINTK is not set
CONFIG_HVC_DRIVER=y
CONFIG_VIRTIO_CONSOLE=y
# CONFIG_IPMI_HANDLER is not set
# CONFIG_HW_RANDOM is not set
# CONFIG_NVRAM is not set
# CONFIG_R3964 is not set
# CONFIG_APPLICOM is not set
# CONFIG_MWAVE is not set
# CONFIG_RAW_DRIVER is not set
# CONFIG_HPET is not set
# CONFIG_HANGCHECK_TIMER is not set
# CONFIG_TCG_TPM is not set
# CONFIG_TELCLOCK is not set
CONFIG_DEVPORT=y
# CONFIG_XILLYBUS is not set
#
# I2C support
#
# CONFIG_I2C is not set
# CONFIG_SPI is not set
# CONFIG_SPMI is not set
# CONFIG_HSI is not set
#
# PPS support
#
# CONFIG_PPS is not set
#
# PPS generators support
#
#
# PTP clock support
#
# CONFIG_PTP_1588_CLOCK is not set
#
# Enable PHYLIB and NETWORK_PHY_TIMESTAMPING to see the additional clocks.
#
CONFIG_ARCH_WANT_OPTIONAL_GPIOLIB=y
# CONFIG_GPIOLIB is not set
# CONFIG_W1 is not set
# CONFIG_POWER_SUPPLY is not set
# CONFIG_POWER_RESET is not set
# CONFIG_POWER_AVS is not set
# CONFIG_HWMON is not set
# CONFIG_THERMAL is not set
# CONFIG_WATCHDOG is not set
CONFIG_SSB_POSSIBLE=y
#
# Sonics Silicon Backplane
#
# CONFIG_SSB is not set
CONFIG_BCMA_POSSIBLE=y
#
# Broadcom specific AMBA
#
# CONFIG_BCMA is not set
#
# Multifunction device drivers
#
# CONFIG_MFD_CORE is not set
# CONFIG_MFD_CROS_EC is not set
# CONFIG_HTC_PASIC3 is not set
# CONFIG_LPC_ICH is not set
# CONFIG_LPC_SCH is not set
# CONFIG_MFD_INTEL_LPSS_ACPI is not set
# CONFIG_MFD_INTEL_LPSS_PCI is not set
# CONFIG_MFD_JANZ_CMODIO is not set
# CONFIG_MFD_KEMPLD is not set
# CONFIG_MFD_MT6397 is not set
# CONFIG_MFD_RDC321X is not set
# CONFIG_MFD_RTSX_PCI is not set
# CONFIG_MFD_SM501 is not set
# CONFIG_ABX500_CORE is not set
# CONFIG_MFD_SYSCON is not set
# CONFIG_MFD_TI_AM335X_TSCADC is not set
# CONFIG_MFD_TMIO is not set
# CONFIG_MFD_VX855 is not set
# CONFIG_REGULATOR is not set
# CONFIG_MEDIA_SUPPORT is not set
#
# Graphics support
#
# CONFIG_AGP is not set
# CONFIG_VGA_ARB is not set
# CONFIG_VGA_SWITCHEROO is not set
# CONFIG_DRM is not set
#
# ACP (Audio CoProcessor) Configuration
#
# CONFIG_DRM_AMD_ACP is not set
#
# Frame buffer Devices
#
# CONFIG_FB is not set
# CONFIG_BACKLIGHT_LCD_SUPPORT is not set
# CONFIG_VGASTATE is not set
# CONFIG_SOUND is not set
#
# HID support
#
# CONFIG_HID is not set
CONFIG_USB_OHCI_LITTLE_ENDIAN=y
# CONFIG_USB_SUPPORT is not set
# CONFIG_UWB is not set
# CONFIG_MMC is not set
# CONFIG_MEMSTICK is not set
# CONFIG_NEW_LEDS is not set
# CONFIG_ACCESSIBILITY is not set
# CONFIG_INFINIBAND is not set
CONFIG_EDAC_ATOMIC_SCRUB=y
CONFIG_EDAC_SUPPORT=y
# CONFIG_EDAC is not set
CONFIG_RTC_LIB=y
# CONFIG_RTC_CLASS is not set
# CONFIG_DMADEVICES is not set
# CONFIG_AUXDISPLAY is not set
# CONFIG_UIO is not set
# CONFIG_VIRT_DRIVERS is not set
CONFIG_VIRTIO=y
#
# Virtio drivers
#
CONFIG_VIRTIO_PCI=y
CONFIG_VIRTIO_PCI_LEGACY=y
CONFIG_VIRTIO_BALLOON=y
# CONFIG_VIRTIO_INPUT is not set
CONFIG_VIRTIO_MMIO=y
# CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES is not set
#
# Microsoft Hyper-V guest support
#
# CONFIG_STAGING is not set
# CONFIG_X86_PLATFORM_DEVICES is not set
# CONFIG_CHROME_PLATFORMS is not set
#
# Hardware Spinlock drivers
#
#
# Clock Source drivers
#
CONFIG_CLKEVT_I8253=y
CONFIG_CLKBLD_I8253=y
# CONFIG_ATMEL_PIT is not set
# CONFIG_SH_TIMER_CMT is not set
# CONFIG_SH_TIMER_MTU2 is not set
# CONFIG_SH_TIMER_TMU is not set
# CONFIG_EM_TIMER_STI is not set
# CONFIG_MAILBOX is not set
# CONFIG_IOMMU_SUPPORT is not set
#
# Remoteproc drivers
#
# CONFIG_STE_MODEM_RPROC is not set
#
# Rpmsg drivers
#
#
# SOC (System On Chip) specific Drivers
#
# CONFIG_SUNXI_SRAM is not set
# CONFIG_SOC_TI is not set
# CONFIG_PM_DEVFREQ is not set
# CONFIG_EXTCON is not set
# CONFIG_MEMORY is not set
# CONFIG_IIO is not set
# CONFIG_NTB is not set
# CONFIG_VME_BUS is not set
# CONFIG_PWM is not set
CONFIG_ARM_GIC_MAX_NR=1
# CONFIG_IPACK_BUS is not set
# CONFIG_RESET_CONTROLLER is not set
# CONFIG_FMC is not set
#
# PHY Subsystem
#
# CONFIG_GENERIC_PHY is not set
# CONFIG_PHY_PXA_28NM_HSIC is not set
# CONFIG_PHY_PXA_28NM_USB2 is not set
# CONFIG_BCM_KONA_USB2_PHY is not set
# CONFIG_POWERCAP is not set
# CONFIG_MCB is not set
#
# Performance monitor support
#
# CONFIG_RAS is not set
# CONFIG_THUNDERBOLT is not set
#
# Android
#
# CONFIG_ANDROID is not set
# CONFIG_LIBNVDIMM is not set
# CONFIG_NVMEM is not set
# CONFIG_STM is not set
# CONFIG_INTEL_TH is not set
#
# FPGA Configuration Support
#
# CONFIG_FPGA is not set
#
# Firmware Drivers
#
# CONFIG_EDD is not set
# CONFIG_FIRMWARE_MEMMAP is not set
# CONFIG_DELL_RBU is not set
# CONFIG_DCDBAS is not set
# CONFIG_ISCSI_IBFT_FIND is not set
# CONFIG_FW_CFG_SYSFS is not set
# CONFIG_GOOGLE_FIRMWARE is not set
#
# File systems
#
CONFIG_DCACHE_WORD_ACCESS=y
# CONFIG_EXT2_FS is not set
CONFIG_EXT3_FS=y
# CONFIG_EXT3_FS_POSIX_ACL is not set
# CONFIG_EXT3_FS_SECURITY is not set
CONFIG_EXT4_FS=y
# CONFIG_EXT4_USE_FOR_EXT2 is not set
# CONFIG_EXT4_FS_POSIX_ACL is not set
# CONFIG_EXT4_FS_SECURITY is not set
# CONFIG_EXT4_ENCRYPTION is not set
# CONFIG_EXT4_DEBUG is not set
CONFIG_JBD2=y
# CONFIG_JBD2_DEBUG is not set
CONFIG_FS_MBCACHE=y
# CONFIG_REISERFS_FS is not set
# CONFIG_JFS_FS is not set
# CONFIG_XFS_FS is not set
# CONFIG_GFS2_FS is not set
# CONFIG_BTRFS_FS is not set
# CONFIG_NILFS2_FS is not set
# CONFIG_F2FS_FS is not set
# CONFIG_FS_DAX is not set
# CONFIG_FS_POSIX_ACL is not set
CONFIG_FILE_LOCKING=y
# CONFIG_MANDATORY_FILE_LOCKING is not set
# CONFIG_FS_ENCRYPTION is not set
# CONFIG_FSNOTIFY is not set
# CONFIG_DNOTIFY is not set
# CONFIG_INOTIFY_USER is not set
# CONFIG_FANOTIFY is not set
# CONFIG_QUOTA is not set
# CONFIG_QUOTACTL is not set
# CONFIG_AUTOFS4_FS is not set
# CONFIG_FUSE_FS is not set
# CONFIG_OVERLAY_FS is not set
#
# Caches
#
# CONFIG_FSCACHE is not set
#
# CD-ROM/DVD Filesystems
#
# CONFIG_ISO9660_FS is not set
# CONFIG_UDF_FS is not set
#
# DOS/FAT/NT Filesystems
#
# CONFIG_MSDOS_FS is not set
# CONFIG_VFAT_FS is not set
# CONFIG_NTFS_FS is not set
#
# Pseudo filesystems
#
CONFIG_PROC_FS=y
CONFIG_PROC_KCORE=y
CONFIG_PROC_SYSCTL=y
CONFIG_PROC_PAGE_MONITOR=y
CONFIG_PROC_CHILDREN=y
CONFIG_KERNFS=y
CONFIG_SYSFS=y
CONFIG_TMPFS=y
# CONFIG_TMPFS_POSIX_ACL is not set
# CONFIG_TMPFS_XATTR is not set
CONFIG_HUGETLBFS=y
CONFIG_HUGETLB_PAGE=y
# CONFIG_CONFIGFS_FS is not set
# CONFIG_MISC_FILESYSTEMS is not set
CONFIG_NETWORK_FILESYSTEMS=y
# CONFIG_NFS_FS is not set
# CONFIG_NFSD is not set
# CONFIG_CEPH_FS is not set
# CONFIG_CIFS is not set
# CONFIG_NCP_FS is not set
# CONFIG_CODA_FS is not set
# CONFIG_AFS_FS is not set
CONFIG_9P_FS=y
# CONFIG_9P_FS_POSIX_ACL is not set
# CONFIG_9P_FS_SECURITY is not set
CONFIG_NLS=y
CONFIG_NLS_DEFAULT="iso8859-1"
# CONFIG_NLS_CODEPAGE_437 is not set
# CONFIG_NLS_CODEPAGE_737 is not set
# CONFIG_NLS_CODEPAGE_775 is not set
# CONFIG_NLS_CODEPAGE_850 is not set
# CONFIG_NLS_CODEPAGE_852 is not set
# CONFIG_NLS_CODEPAGE_855 is not set
# CONFIG_NLS_CODEPAGE_857 is not set
# CONFIG_NLS_CODEPAGE_860 is not set
# CONFIG_NLS_CODEPAGE_861 is not set
# CONFIG_NLS_CODEPAGE_862 is not set
# CONFIG_NLS_CODEPAGE_863 is not set
# CONFIG_NLS_CODEPAGE_864 is not set
# CONFIG_NLS_CODEPAGE_865 is not set
# CONFIG_NLS_CODEPAGE_866 is not set
# CONFIG_NLS_CODEPAGE_869 is not set
# CONFIG_NLS_CODEPAGE_936 is not set
# CONFIG_NLS_CODEPAGE_950 is not set
# CONFIG_NLS_CODEPAGE_932 is not set
# CONFIG_NLS_CODEPAGE_949 is not set
# CONFIG_NLS_CODEPAGE_874 is not set
# CONFIG_NLS_ISO8859_8 is not set
# CONFIG_NLS_CODEPAGE_1250 is not set
# CONFIG_NLS_CODEPAGE_1251 is not set
# CONFIG_NLS_ASCII is not set
# CONFIG_NLS_ISO8859_1 is not set
# CONFIG_NLS_ISO8859_2 is not set
# CONFIG_NLS_ISO8859_3 is not set
# CONFIG_NLS_ISO8859_4 is not set
# CONFIG_NLS_ISO8859_5 is not set
# CONFIG_NLS_ISO8859_6 is not set
# CONFIG_NLS_ISO8859_7 is not set
# CONFIG_NLS_ISO8859_9 is not set
# CONFIG_NLS_ISO8859_13 is not set
# CONFIG_NLS_ISO8859_14 is not set
# CONFIG_NLS_ISO8859_15 is not set
# CONFIG_NLS_KOI8_R is not set
# CONFIG_NLS_KOI8_U is not set
# CONFIG_NLS_MAC_ROMAN is not set
# CONFIG_NLS_MAC_CELTIC is not set
# CONFIG_NLS_MAC_CENTEURO is not set
# CONFIG_NLS_MAC_CROATIAN is not set
# CONFIG_NLS_MAC_CYRILLIC is not set
# CONFIG_NLS_MAC_GAELIC is not set
# CONFIG_NLS_MAC_GREEK is not set
# CONFIG_NLS_MAC_ICELAND is not set
# CONFIG_NLS_MAC_INUIT is not set
# CONFIG_NLS_MAC_ROMANIAN is not set
# CONFIG_NLS_MAC_TURKISH is not set
# CONFIG_NLS_UTF8 is not set
#
# Kernel hacking
#
CONFIG_TRACE_IRQFLAGS_SUPPORT=y
#
# printk and dmesg options
#
# CONFIG_PRINTK_TIME is not set
CONFIG_MESSAGE_LOGLEVEL_DEFAULT=4
# CONFIG_BOOT_PRINTK_DELAY is not set
# CONFIG_DYNAMIC_DEBUG is not set
#
# Compile-time checks and compiler options
#
CONFIG_DEBUG_INFO=y
# CONFIG_DEBUG_INFO_REDUCED is not set
# CONFIG_DEBUG_INFO_SPLIT is not set
# CONFIG_DEBUG_INFO_DWARF4 is not set
CONFIG_GDB_SCRIPTS=y
CONFIG_ENABLE_WARN_DEPRECATED=y
# CONFIG_ENABLE_MUST_CHECK is not set
CONFIG_FRAME_WARN=2048
CONFIG_STRIP_ASM_SYMS=y
CONFIG_READABLE_ASM=y
# CONFIG_UNUSED_SYMBOLS is not set
# CONFIG_PAGE_OWNER is not set
CONFIG_DEBUG_FS=y
# CONFIG_HEADERS_CHECK is not set
# CONFIG_DEBUG_SECTION_MISMATCH is not set
CONFIG_SECTION_MISMATCH_WARN_ONLY=y
CONFIG_ARCH_WANT_FRAME_POINTERS=y
CONFIG_FRAME_POINTER=y
# CONFIG_STACK_VALIDATION is not set
# CONFIG_DEBUG_FORCE_WEAK_PER_CPU is not set
CONFIG_MAGIC_SYSRQ=y
CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE=0x1
CONFIG_DEBUG_KERNEL=y
#
# Memory Debugging
#
# CONFIG_PAGE_EXTENSION is not set
# CONFIG_DEBUG_PAGEALLOC is not set
# CONFIG_PAGE_POISONING is not set
# CONFIG_DEBUG_PAGE_REF is not set
# CONFIG_DEBUG_OBJECTS is not set
# CONFIG_SLUB_DEBUG_ON is not set
# CONFIG_SLUB_STATS is not set
CONFIG_HAVE_DEBUG_KMEMLEAK=y
# CONFIG_DEBUG_KMEMLEAK is not set
# CONFIG_DEBUG_STACK_USAGE is not set
# CONFIG_DEBUG_VM is not set
# CONFIG_DEBUG_VIRTUAL is not set
# CONFIG_DEBUG_MEMORY_INIT is not set
# CONFIG_DEBUG_PER_CPU_MAPS is not set
CONFIG_HAVE_DEBUG_STACKOVERFLOW=y
# CONFIG_DEBUG_STACKOVERFLOW is not set
CONFIG_HAVE_ARCH_KMEMCHECK=y
CONFIG_HAVE_ARCH_KASAN=y
# CONFIG_KASAN is not set
CONFIG_ARCH_HAS_KCOV=y
# CONFIG_KCOV is not set
# CONFIG_DEBUG_SHIRQ is not set
#
# Debug Lockups and Hangs
#
CONFIG_LOCKUP_DETECTOR=y
CONFIG_HARDLOCKUP_DETECTOR=y
# CONFIG_BOOTPARAM_HARDLOCKUP_PANIC is not set
CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE=0
# CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC is not set
CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE=0
# CONFIG_DETECT_HUNG_TASK is not set
# CONFIG_WQ_WATCHDOG is not set
# CONFIG_PANIC_ON_OOPS is not set
CONFIG_PANIC_ON_OOPS_VALUE=0
CONFIG_PANIC_TIMEOUT=0
# CONFIG_SCHED_DEBUG is not set
# CONFIG_SCHED_INFO is not set
# CONFIG_SCHEDSTATS is not set
# CONFIG_SCHED_STACK_END_CHECK is not set
# CONFIG_DEBUG_TIMEKEEPING is not set
# CONFIG_TIMER_STATS is not set
# CONFIG_DEBUG_PREEMPT is not set
#
# Lock Debugging (spinlocks, mutexes, etc...)
#
# CONFIG_DEBUG_RT_MUTEXES is not set
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_MUTEXES=y
# CONFIG_DEBUG_WW_MUTEX_SLOWPATH is not set
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_PROVE_LOCKING=y
CONFIG_LOCKDEP=y
CONFIG_LOCK_STAT=y
# CONFIG_DEBUG_LOCKDEP is not set
CONFIG_DEBUG_ATOMIC_SLEEP=y
# CONFIG_DEBUG_LOCKING_API_SELFTESTS is not set
# CONFIG_LOCK_TORTURE_TEST is not set
CONFIG_TRACE_IRQFLAGS=y
CONFIG_STACKTRACE=y
# CONFIG_DEBUG_KOBJECT is not set
CONFIG_DEBUG_BUGVERBOSE=y
# CONFIG_DEBUG_LIST is not set
# CONFIG_DEBUG_PI_LIST is not set
# CONFIG_DEBUG_SG is not set
# CONFIG_DEBUG_NOTIFIERS is not set
# CONFIG_DEBUG_CREDENTIALS is not set
#
# RCU Debugging
#
CONFIG_PROVE_RCU=y
# CONFIG_PROVE_RCU_REPEATEDLY is not set
# CONFIG_SPARSE_RCU_POINTER is not set
# CONFIG_TORTURE_TEST is not set
# CONFIG_RCU_TORTURE_TEST is not set
CONFIG_RCU_CPU_STALL_TIMEOUT=60
# CONFIG_RCU_TRACE is not set
# CONFIG_RCU_EQS_DEBUG is not set
# CONFIG_DEBUG_WQ_FORCE_RR_CPU is not set
# CONFIG_DEBUG_BLOCK_EXT_DEVT is not set
# CONFIG_CPU_HOTPLUG_STATE_CONTROL is not set
# CONFIG_NOTIFIER_ERROR_INJECTION is not set
# CONFIG_FAULT_INJECTION is not set
# CONFIG_LATENCYTOP is not set
CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS=y
# CONFIG_DEBUG_STRICT_USER_COPY_CHECKS is not set
CONFIG_USER_STACKTRACE_SUPPORT=y
CONFIG_NOP_TRACER=y
CONFIG_HAVE_FUNCTION_TRACER=y
CONFIG_HAVE_FUNCTION_GRAPH_TRACER=y
CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST=y
CONFIG_HAVE_DYNAMIC_FTRACE=y
CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS=y
CONFIG_HAVE_FTRACE_MCOUNT_RECORD=y
CONFIG_HAVE_SYSCALL_TRACEPOINTS=y
CONFIG_HAVE_FENTRY=y
CONFIG_HAVE_C_RECORDMCOUNT=y
CONFIG_TRACER_MAX_TRACE=y
CONFIG_TRACE_CLOCK=y
CONFIG_RING_BUFFER=y
CONFIG_EVENT_TRACING=y
CONFIG_CONTEXT_SWITCH_TRACER=y
CONFIG_RING_BUFFER_ALLOW_SWAP=y
CONFIG_TRACING=y
CONFIG_GENERIC_TRACER=y
CONFIG_TRACING_SUPPORT=y
CONFIG_FTRACE=y
CONFIG_FUNCTION_TRACER=y
CONFIG_FUNCTION_GRAPH_TRACER=y
CONFIG_IRQSOFF_TRACER=y
CONFIG_PREEMPT_TRACER=y
CONFIG_SCHED_TRACER=y
CONFIG_FTRACE_SYSCALLS=y
CONFIG_TRACER_SNAPSHOT=y
CONFIG_TRACER_SNAPSHOT_PER_CPU_SWAP=y
CONFIG_BRANCH_PROFILE_NONE=y
# CONFIG_PROFILE_ANNOTATED_BRANCHES is not set
# CONFIG_PROFILE_ALL_BRANCHES is not set
# CONFIG_STACK_TRACER is not set
# CONFIG_BLK_DEV_IO_TRACE is not set
CONFIG_KPROBE_EVENT=y
CONFIG_UPROBE_EVENT=y
CONFIG_PROBE_EVENTS=y
CONFIG_DYNAMIC_FTRACE=y
CONFIG_DYNAMIC_FTRACE_WITH_REGS=y
# CONFIG_FUNCTION_PROFILER is not set
CONFIG_FTRACE_MCOUNT_RECORD=y
# CONFIG_FTRACE_STARTUP_TEST is not set
# CONFIG_MMIOTRACE is not set
# CONFIG_TRACEPOINT_BENCHMARK is not set
# CONFIG_RING_BUFFER_BENCHMARK is not set
# CONFIG_RING_BUFFER_STARTUP_TEST is not set
# CONFIG_TRACE_ENUM_MAP_FILE is not set
#
# Runtime Testing
#
# CONFIG_LKDTM is not set
# CONFIG_TEST_LIST_SORT is not set
# CONFIG_KPROBES_SANITY_TEST is not set
# CONFIG_BACKTRACE_SELF_TEST is not set
# CONFIG_RBTREE_TEST is not set
# CONFIG_INTERVAL_TREE_TEST is not set
# CONFIG_PERCPU_TEST is not set
# CONFIG_ATOMIC64_SELFTEST is not set
# CONFIG_TEST_HEXDUMP is not set
# CONFIG_TEST_STRING_HELPERS is not set
# CONFIG_TEST_KSTRTOX is not set
# CONFIG_TEST_PRINTF is not set
# CONFIG_TEST_BITMAP is not set
# CONFIG_TEST_RHASHTABLE is not set
# CONFIG_PROVIDE_OHCI1394_DMA_INIT is not set
# CONFIG_DMA_API_DEBUG is not set
# CONFIG_TEST_LKM is not set
# CONFIG_TEST_USER_COPY is not set
# CONFIG_TEST_BPF is not set
# CONFIG_TEST_FIRMWARE is not set
# CONFIG_TEST_UDELAY is not set
# CONFIG_MEMTEST is not set
# CONFIG_TEST_STATIC_KEYS is not set
# CONFIG_SAMPLES is not set
CONFIG_HAVE_ARCH_KGDB=y
# CONFIG_KGDB is not set
CONFIG_ARCH_HAS_UBSAN_SANITIZE_ALL=y
# CONFIG_UBSAN is not set
CONFIG_ARCH_HAS_DEVMEM_IS_ALLOWED=y
# CONFIG_STRICT_DEVMEM is not set
# CONFIG_X86_VERBOSE_BOOTUP is not set
CONFIG_EARLY_PRINTK=y
# CONFIG_EARLY_PRINTK_DBGP is not set
# CONFIG_X86_PTDUMP_CORE is not set
# CONFIG_X86_PTDUMP is not set
# CONFIG_DEBUG_RODATA_TEST is not set
# CONFIG_DEBUG_WX is not set
# CONFIG_DEBUG_SET_MODULE_RONX is not set
# CONFIG_DEBUG_NX_TEST is not set
# CONFIG_DOUBLEFAULT is not set
# CONFIG_DEBUG_TLBFLUSH is not set
# CONFIG_IOMMU_STRESS is not set
CONFIG_HAVE_MMIOTRACE_SUPPORT=y
# CONFIG_X86_DECODER_SELFTEST is not set
CONFIG_IO_DELAY_TYPE_0X80=0
CONFIG_IO_DELAY_TYPE_0XED=1
CONFIG_IO_DELAY_TYPE_UDELAY=2
CONFIG_IO_DELAY_TYPE_NONE=3
CONFIG_IO_DELAY_0X80=y
# CONFIG_IO_DELAY_0XED is not set
# CONFIG_IO_DELAY_UDELAY is not set
# CONFIG_IO_DELAY_NONE is not set
CONFIG_DEFAULT_IO_DELAY_TYPE=0
# CONFIG_DEBUG_BOOT_PARAMS is not set
# CONFIG_CPA_DEBUG is not set
# CONFIG_OPTIMIZE_INLINING is not set
# CONFIG_DEBUG_ENTRY is not set
# CONFIG_DEBUG_NMI_SELFTEST is not set
# CONFIG_X86_DEBUG_FPU is not set
# CONFIG_PUNIT_ATOM_DEBUG is not set
#
# Security options
#
# CONFIG_KEYS is not set
# CONFIG_SECURITY_DMESG_RESTRICT is not set
# CONFIG_SECURITY is not set
# CONFIG_SECURITYFS is not set
CONFIG_DEFAULT_SECURITY_DAC=y
CONFIG_DEFAULT_SECURITY=""
CONFIG_CRYPTO=y
#
# Crypto core or helper
#
CONFIG_CRYPTO_ALGAPI=y
CONFIG_CRYPTO_ALGAPI2=y
CONFIG_CRYPTO_HASH=y
CONFIG_CRYPTO_HASH2=y
# CONFIG_CRYPTO_RSA is not set
# CONFIG_CRYPTO_MANAGER is not set
# CONFIG_CRYPTO_MANAGER2 is not set
# CONFIG_CRYPTO_USER is not set
# CONFIG_CRYPTO_GF128MUL is not set
# CONFIG_CRYPTO_NULL is not set
# CONFIG_CRYPTO_PCRYPT is not set
# CONFIG_CRYPTO_CRYPTD is not set
# CONFIG_CRYPTO_MCRYPTD is not set
# CONFIG_CRYPTO_AUTHENC is not set
# CONFIG_CRYPTO_TEST is not set
#
# Authenticated Encryption with Associated Data
#
# CONFIG_CRYPTO_CCM is not set
# CONFIG_CRYPTO_GCM is not set
# CONFIG_CRYPTO_CHACHA20POLY1305 is not set
# CONFIG_CRYPTO_SEQIV is not set
# CONFIG_CRYPTO_ECHAINIV is not set
#
# Block modes
#
# CONFIG_CRYPTO_CBC is not set
# CONFIG_CRYPTO_CTR is not set
# CONFIG_CRYPTO_CTS is not set
# CONFIG_CRYPTO_ECB is not set
# CONFIG_CRYPTO_LRW is not set
# CONFIG_CRYPTO_PCBC is not set
# CONFIG_CRYPTO_XTS is not set
# CONFIG_CRYPTO_KEYWRAP is not set
#
# Hash modes
#
# CONFIG_CRYPTO_CMAC is not set
# CONFIG_CRYPTO_HMAC is not set
# CONFIG_CRYPTO_XCBC is not set
# CONFIG_CRYPTO_VMAC is not set
#
# Digest
#
CONFIG_CRYPTO_CRC32C=y
# CONFIG_CRYPTO_CRC32C_INTEL is not set
# CONFIG_CRYPTO_CRC32 is not set
# CONFIG_CRYPTO_CRC32_PCLMUL is not set
# CONFIG_CRYPTO_CRCT10DIF is not set
# CONFIG_CRYPTO_GHASH is not set
# CONFIG_CRYPTO_POLY1305 is not set
# CONFIG_CRYPTO_POLY1305_X86_64 is not set
# CONFIG_CRYPTO_MD4 is not set
# CONFIG_CRYPTO_MD5 is not set
# CONFIG_CRYPTO_MICHAEL_MIC is not set
# CONFIG_CRYPTO_RMD128 is not set
# CONFIG_CRYPTO_RMD160 is not set
# CONFIG_CRYPTO_RMD256 is not set
# CONFIG_CRYPTO_RMD320 is not set
# CONFIG_CRYPTO_SHA1 is not set
# CONFIG_CRYPTO_SHA1_SSSE3 is not set
# CONFIG_CRYPTO_SHA256_SSSE3 is not set
# CONFIG_CRYPTO_SHA512_SSSE3 is not set
# CONFIG_CRYPTO_SHA1_MB is not set
# CONFIG_CRYPTO_SHA256 is not set
# CONFIG_CRYPTO_SHA512 is not set
# CONFIG_CRYPTO_TGR192 is not set
# CONFIG_CRYPTO_WP512 is not set
# CONFIG_CRYPTO_GHASH_CLMUL_NI_INTEL is not set
#
# Ciphers
#
CONFIG_CRYPTO_AES=y
# CONFIG_CRYPTO_AES_X86_64 is not set
# CONFIG_CRYPTO_AES_NI_INTEL is not set
# CONFIG_CRYPTO_ANUBIS is not set
# CONFIG_CRYPTO_ARC4 is not set
# CONFIG_CRYPTO_BLOWFISH is not set
# CONFIG_CRYPTO_BLOWFISH_X86_64 is not set
# CONFIG_CRYPTO_CAMELLIA is not set
# CONFIG_CRYPTO_CAMELLIA_X86_64 is not set
# CONFIG_CRYPTO_CAMELLIA_AESNI_AVX_X86_64 is not set
# CONFIG_CRYPTO_CAMELLIA_AESNI_AVX2_X86_64 is not set
# CONFIG_CRYPTO_CAST5 is not set
# CONFIG_CRYPTO_CAST5_AVX_X86_64 is not set
# CONFIG_CRYPTO_CAST6 is not set
# CONFIG_CRYPTO_CAST6_AVX_X86_64 is not set
# CONFIG_CRYPTO_DES is not set
# CONFIG_CRYPTO_DES3_EDE_X86_64 is not set
# CONFIG_CRYPTO_FCRYPT is not set
# CONFIG_CRYPTO_KHAZAD is not set
# CONFIG_CRYPTO_SALSA20 is not set
# CONFIG_CRYPTO_SALSA20_X86_64 is not set
# CONFIG_CRYPTO_CHACHA20 is not set
# CONFIG_CRYPTO_CHACHA20_X86_64 is not set
# CONFIG_CRYPTO_SEED is not set
# CONFIG_CRYPTO_SERPENT is not set
# CONFIG_CRYPTO_SERPENT_SSE2_X86_64 is not set
# CONFIG_CRYPTO_SERPENT_AVX_X86_64 is not set
# CONFIG_CRYPTO_SERPENT_AVX2_X86_64 is not set
# CONFIG_CRYPTO_TEA is not set
# CONFIG_CRYPTO_TWOFISH is not set
# CONFIG_CRYPTO_TWOFISH_X86_64 is not set
# CONFIG_CRYPTO_TWOFISH_X86_64_3WAY is not set
# CONFIG_CRYPTO_TWOFISH_AVX_X86_64 is not set
#
# Compression
#
# CONFIG_CRYPTO_DEFLATE is not set
# CONFIG_CRYPTO_LZO is not set
# CONFIG_CRYPTO_842 is not set
# CONFIG_CRYPTO_LZ4 is not set
# CONFIG_CRYPTO_LZ4HC is not set
#
# Random Number Generation
#
# CONFIG_CRYPTO_ANSI_CPRNG is not set
# CONFIG_CRYPTO_DRBG_MENU is not set
# CONFIG_CRYPTO_JITTERENTROPY is not set
# CONFIG_CRYPTO_USER_API_HASH is not set
# CONFIG_CRYPTO_USER_API_SKCIPHER is not set
# CONFIG_CRYPTO_USER_API_RNG is not set
# CONFIG_CRYPTO_USER_API_AEAD is not set
# CONFIG_CRYPTO_HW is not set
#
# Certificates for signature checking
#
CONFIG_HAVE_KVM=y
CONFIG_VIRTUALIZATION=y
# CONFIG_KVM is not set
CONFIG_BINARY_PRINTF=y
#
# Library routines
#
CONFIG_BITREVERSE=y
# CONFIG_HAVE_ARCH_BITREVERSE is not set
CONFIG_GENERIC_STRNCPY_FROM_USER=y
CONFIG_GENERIC_STRNLEN_USER=y
CONFIG_GENERIC_NET_UTILS=y
CONFIG_GENERIC_FIND_FIRST_BIT=y
CONFIG_GENERIC_PCI_IOMAP=y
CONFIG_GENERIC_IOMAP=y
CONFIG_GENERIC_IO=y
CONFIG_ARCH_USE_CMPXCHG_LOCKREF=y
CONFIG_ARCH_HAS_FAST_MULTIPLIER=y
# CONFIG_CRC_CCITT is not set
CONFIG_CRC16=y
# CONFIG_CRC_T10DIF is not set
# CONFIG_CRC_ITU_T is not set
CONFIG_CRC32=y
# CONFIG_CRC32_SELFTEST is not set
CONFIG_CRC32_SLICEBY8=y
# CONFIG_CRC32_SLICEBY4 is not set
# CONFIG_CRC32_SARWATE is not set
# CONFIG_CRC32_BIT is not set
# CONFIG_CRC7 is not set
# CONFIG_LIBCRC32C is not set
# CONFIG_CRC8 is not set
# CONFIG_AUDIT_ARCH_COMPAT_GENERIC is not set
# CONFIG_RANDOM32_SELFTEST is not set
CONFIG_ZLIB_INFLATE=y
# CONFIG_XZ_DEC is not set
# CONFIG_XZ_DEC_BCJ is not set
CONFIG_DECOMPRESS_GZIP=y
CONFIG_HAS_IOMEM=y
CONFIG_HAS_IOPORT_MAP=y
CONFIG_HAS_DMA=y
CONFIG_CPU_RMAP=y
CONFIG_DQL=y
CONFIG_NLATTR=y
CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE=y
# CONFIG_CORDIC is not set
# CONFIG_DDR is not set
# CONFIG_IRQ_POLL is not set
# CONFIG_SG_SPLIT is not set
CONFIG_ARCH_HAS_SG_CHAIN=y
CONFIG_ARCH_HAS_PMEM_API=y
CONFIG_ARCH_HAS_MMIO_FLUSH=y
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
2016-05-20 20:28 zone_reclaimable() leads to livelock in __alloc_pages_slowpath() Oleg Nesterov
@ 2016-05-21 4:07 ` Tetsuo Handa
2016-05-22 21:17 ` Oleg Nesterov
2016-05-23 7:29 ` Michal Hocko
1 sibling, 1 reply; 14+ messages in thread
From: Tetsuo Handa @ 2016-05-21 4:07 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Andrew Morton, Andrea Arcangeli, Mel Gorman, Michal Hocko,
linux-kernel, linux-mm
On 2016/05/21 5:28, Oleg Nesterov wrote:
> Hello,
>
> Recently I hit the problem, _sometimes_ the system just hangs in OOM situation.
> Surprisingly, this time OOM-killer is innocent ;) and finally I can reproduce
> this more-or-less reliably just running
>
> #include <stdlib.h>
> #include <string.h>
>
> int main(void)
> {
> for (;;) {
> void *p = malloc(1024 * 1024);
> memset(p, 0, 1024 * 1024);
> }
> }
>
> in a loop on the otherwise idle system. 512m RAM, one CPU (but CONFIG_SMP=y),
> no swap, and only one user-space process (apart from test-case above), /bin/sh
> runnning as init with pid==1. I am attaching my .config just in case, but I
> think the problem is not really specific to this configuration.
>
> --------------------------------------------------------------------------------
> It spins in __alloc_pages_slowpath() forever, __alloc_pages_may_oom() is never
> called, it doesn't react to SIGKILL, etc.
>
> This is because zone_reclaimable() is always true in shrink_zones(), and the
> problem goes away if I comment out this code
>
> if (global_reclaim(sc) &&
> !reclaimable && zone_reclaimable(zone))
> reclaimable = true;
>
> in shrink_zones() which otherwise returns this "true" every time, and thus
> __alloc_pages_slowpath() always sees did_some_progress != 0.
>
Michal Hocko's OOM detection rework patchset that removes that code was sent
to Linus 4 hours ago. ( https://marc.info/?l=linux-mm-commits&m=146378862415399 )
Please wait for a few days and try reproducing using linux.git .
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
2016-05-21 4:07 ` Tetsuo Handa
@ 2016-05-22 21:17 ` Oleg Nesterov
0 siblings, 0 replies; 14+ messages in thread
From: Oleg Nesterov @ 2016-05-22 21:17 UTC (permalink / raw)
To: Tetsuo Handa
Cc: Andrew Morton, Andrea Arcangeli, Mel Gorman, Michal Hocko,
linux-kernel, linux-mm
On 05/21, Tetsuo Handa wrote:
>
> On 2016/05/21 5:28, Oleg Nesterov wrote:
> > It spins in __alloc_pages_slowpath() forever, __alloc_pages_may_oom() is never
> > called, it doesn't react to SIGKILL, etc.
> >
> > This is because zone_reclaimable() is always true in shrink_zones(), and the
> > problem goes away if I comment out this code
> >
> > if (global_reclaim(sc) &&
> > !reclaimable && zone_reclaimable(zone))
> > reclaimable = true;
> >
> > in shrink_zones() which otherwise returns this "true" every time, and thus
> > __alloc_pages_slowpath() always sees did_some_progress != 0.
> >
>
> Michal Hocko's OOM detection rework patchset that removes that code was sent
> to Linus 4 hours ago. ( https://marc.info/?l=linux-mm-commits&m=146378862415399 )
> Please wait for a few days and try reproducing using linux.git .
I guess you mean
http://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/mm/vmscan.c?id=fa8c5f033ebb43f925d68c29d297bafd36af7114
"mm, oom: rework oom detection"...
Yes thanks a lot Tetsuo, it should fix the problem.
Cough I can't resist I hate Michal^W the fact this was already fixed ;) Because
it took me some time to understand whats going on, initially it looked like some
subtle and hard-to-reproduce bug in userfaultfd.
Thanks!
Oleg.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
2016-05-20 20:28 zone_reclaimable() leads to livelock in __alloc_pages_slowpath() Oleg Nesterov
2016-05-21 4:07 ` Tetsuo Handa
@ 2016-05-23 7:29 ` Michal Hocko
2016-05-23 15:14 ` Oleg Nesterov
1 sibling, 1 reply; 14+ messages in thread
From: Michal Hocko @ 2016-05-23 7:29 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Andrew Morton, Andrea Arcangeli, Mel Gorman, linux-kernel, linux-mm
Hi,
Tetsuo has already pointed you at my oom detection rework which removes
the zone_reclaimable ugliness (btw. one of the top reasons to rework
this area) and it is likely to fix your problem. I would still like to
understand what happens with your test case because we might want to
prepare a stable patch for older kernels.
On Fri 20-05-16 22:28:17, Oleg Nesterov wrote:
> I don't understand vmscan.c, and in fact I don't even understand NR_PAGES_SCANNED
[...]
> counter... why it has to be atomic/per-cpu? It is always updated under ->lru_lock
> except free_pcppages_bulk/free_one_page try to reset this counter. But note that
> they both do
It doesn't really have to be atomic/per-cpu because it is really updated
under the lock. It just uses the generic vmstat infrastructure...
> nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
> if (nr_scanned)
> __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
>
> and this doesn't look exactly right: zone_page_state() ignores the per-cpu
> ->vm_stat_diff[] counters (and we probably do not want for_each_online_cpu()
> loop here). And I do not know if this is really bad or not, but note that if
> I change calculate_normal_threshold() to return 0, the problem goes away too.
You are absolutely right that this is racy. In the worst case we would
end up missing nr_cpus*threshold scanned pages which would stay behind.
But
bool zone_reclaimable(struct zone *zone)
{
return zone_page_state_snapshot(zone, NR_PAGES_SCANNED) <
zone_reclaimable_pages(zone) * 6;
}
So the left over shouldn't cause it to return true all the time. In
fact it could prematurely say false, right? (note that _snapshot variant
considers per-cpu diffs [1]).
That being said I am not really sure why would the 0 threshold help for
your test case. Could you add some tracing and see what are the numbers
above? Is it possible that zone_reclaimable_pages is some small number
which actuall prevents us to scan anything? Aka a bug is get_scan_count
or somewhere else?
[1] I am not really sure which kernel version have you tested - your
config says 4.6.0-rc7 but this is true since 0db2cb8da89d ("mm, vmscan:
make zone_reclaimable_pages more precise") which is 4.6-rc1.
--
Michal Hocko
SUSE Labs
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
2016-05-23 7:29 ` Michal Hocko
@ 2016-05-23 15:14 ` Oleg Nesterov
2016-05-24 7:16 ` Michal Hocko
0 siblings, 1 reply; 14+ messages in thread
From: Oleg Nesterov @ 2016-05-23 15:14 UTC (permalink / raw)
To: Michal Hocko
Cc: Andrew Morton, Andrea Arcangeli, Mel Gorman, linux-kernel, linux-mm
On 05/23, Michal Hocko wrote:
>
> > nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
> > if (nr_scanned)
> > __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
> >
> > and this doesn't look exactly right: zone_page_state() ignores the per-cpu
> > ->vm_stat_diff[] counters (and we probably do not want for_each_online_cpu()
> > loop here). And I do not know if this is really bad or not, but note that if
> > I change calculate_normal_threshold() to return 0, the problem goes away too.
>
> You are absolutely right that this is racy. In the worst case we would
> end up missing nr_cpus*threshold scanned pages which would stay behind.
and the sum of ->vm_diff[] can be negative, so...
> But
>
> bool zone_reclaimable(struct zone *zone)
> {
> return zone_page_state_snapshot(zone, NR_PAGES_SCANNED) <
> zone_reclaimable_pages(zone) * 6;
> }
>
> So the left over shouldn't cause it to return true all the time.
well if NR_PAGES_SCANNED doesn't grow enough it can even stay negative,
but zone_page_state_snapshot() returns zero in this case. In any case
we can underestimate zone_page_state_snapshot(NR_PAGES_SCANNED).
> In
> fact it could prematurely say false, right? (note that _snapshot variant
> considers per-cpu diffs [1]).
exactly because _snapshot() doesn't ignore the per-cpu counters.
> That being said I am not really sure why would the 0 threshold help for
> your test case.
Neither me. Except, of course, threshold==0 means the the code above will
work correctly. But I do not think this was the root of the problem.
> Could you add some tracing and see what are the numbers
> above?
with the patch below I can press Ctrl-C when it hangs, this breaks the
endless loop and the output looks like
vmscan: ZONE=ffffffff8189f180 0 scanned=0 pages=6
vmscan: ZONE=ffffffff8189eb00 0 scanned=1 pages=0
...
vmscan: ZONE=ffffffff8189eb00 0 scanned=2 pages=1
vmscan: ZONE=ffffffff8189f180 0 scanned=4 pages=6
...
vmscan: ZONE=ffffffff8189f180 0 scanned=4 pages=6
vmscan: ZONE=ffffffff8189f180 0 scanned=4 pages=6
the numbers are always small.
> [1] I am not really sure which kernel version have you tested - your
> config says 4.6.0-rc7 but this is true since 0db2cb8da89d ("mm, vmscan:
> make zone_reclaimable_pages more precise") which is 4.6-rc1.
Yes, I am on c5114626f33b62fa7595e57d87f33d9d1f8298a2, it has this change.
Oleg.
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 142cb61..6d221f9 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2614,6 +2614,12 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
if (shrink_zone(zone, sc, zone_idx(zone) == classzone_idx))
reclaimable = true;
+if (fatal_signal_pending(current))
+ pr_crit("ZONE=%p %d scanned=%ld pages=%ld\n",
+ zone, reclaimable,
+ zone_page_state_snapshot(zone, NR_PAGES_SCANNED),
+ zone_reclaimable_pages(zone));
+else
if (global_reclaim(sc) &&
!reclaimable && zone_reclaimable(zone))
reclaimable = true;
^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
2016-05-23 15:14 ` Oleg Nesterov
@ 2016-05-24 7:16 ` Michal Hocko
2016-05-24 22:43 ` Oleg Nesterov
0 siblings, 1 reply; 14+ messages in thread
From: Michal Hocko @ 2016-05-24 7:16 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Andrew Morton, Andrea Arcangeli, Mel Gorman, linux-kernel, linux-mm
On Mon 23-05-16 17:14:19, Oleg Nesterov wrote:
> On 05/23, Michal Hocko wrote:
[...]
> > Could you add some tracing and see what are the numbers
> > above?
>
> with the patch below I can press Ctrl-C when it hangs, this breaks the
> endless loop and the output looks like
>
> vmscan: ZONE=ffffffff8189f180 0 scanned=0 pages=6
> vmscan: ZONE=ffffffff8189eb00 0 scanned=1 pages=0
> ...
> vmscan: ZONE=ffffffff8189eb00 0 scanned=2 pages=1
> vmscan: ZONE=ffffffff8189f180 0 scanned=4 pages=6
> ...
> vmscan: ZONE=ffffffff8189f180 0 scanned=4 pages=6
> vmscan: ZONE=ffffffff8189f180 0 scanned=4 pages=6
>
> the numbers are always small.
Small but scanned is not 0 and constant which means it either gets reset
repeatedly (something gets freed) or we have stopped scanning. Which
pattern can you see? I assume that the swap space is full at the time
(could you add get_nr_swap_pages() to the output). Also zone->name would
be better than the pointer.
I am trying to reproduce but your test case always hits the oom killer:
This is in a qemu x86_64 virtual machine:
# free
total used free shared buffers cached
Mem: 490212 96788 393424 0 3196 9976
-/+ buffers/cache: 83616 406596
Swap: 138236 57740 80496
I have tried with much larger swap space but no change except for the
run time of the test which is expected.
# grep "^processor" /proc/cpuinfo | wc -l
1
[... Skipped several previous attempts ...]
[ 695.215235] vmscan: XXX: zone:DMA32 nr_pages_scanned:0 reclaimable:20
[ 695.215245] vmscan: XXX: zone:DMA32 nr_pages_scanned:0 reclaimable:20
[ 695.215255] vmscan: XXX: zone:DMA32 nr_pages_scanned:0 reclaimable:20
[ 695.215282] vmscan: XXX: zone:DMA32 nr_pages_scanned:1 reclaimable:27
[ 695.215303] vmscan: XXX: zone:DMA32 nr_pages_scanned:5 reclaimable:27
[ 695.215327] vmscan: XXX: zone:DMA32 nr_pages_scanned:18 reclaimable:27
[ 695.215351] vmscan: XXX: zone:DMA32 nr_pages_scanned:45 reclaimable:27
[ 695.215362] vmscan: XXX: zone:DMA32 nr_pages_scanned:45 reclaimable:27
[ 695.215373] vmscan: XXX: zone:DMA32 nr_pages_scanned:45 reclaimable:27
[ 695.215382] vmscan: XXX: zone:DMA32 nr_pages_scanned:45 reclaimable:27
[ 695.215392] vmscan: XXX: zone:DMA32 nr_pages_scanned:45 reclaimable:27
[ 695.215402] vmscan: XXX: zone:DMA32 nr_pages_scanned:45 reclaimable:27
[ 695.215412] vmscan: XXX: zone:DMA32 nr_pages_scanned:45 reclaimable:27
[ 695.215422] vmscan: XXX: zone:DMA32 nr_pages_scanned:45 reclaimable:27
[ 695.215431] vmscan: XXX: zone:DMA32 nr_pages_scanned:45 reclaimable:27
[ 695.215442] vmscan: XXX: zone:DMA32 nr_pages_scanned:46 reclaimable:27
[ 695.215462] vmscan: XXX: zone:DMA32 nr_pages_scanned:48 reclaimable:27
[ 695.215482] vmscan: XXX: zone:DMA32 nr_pages_scanned:53 reclaimable:27
[ 695.215504] vmscan: XXX: zone:DMA32 nr_pages_scanned:63 reclaimable:27
[ 695.215528] vmscan: XXX: zone:DMA32 nr_pages_scanned:90 reclaimable:27
[...]
[ 695.215620] vmscan: XXX: zone:DMA32 nr_pages_scanned:91 reclaimable:27
[ 695.215640] vmscan: XXX: zone:DMA32 nr_pages_scanned:94 reclaimable:27
[ 695.215659] vmscan: XXX: zone:DMA32 nr_pages_scanned:100 reclaimable:27
[ 695.215683] vmscan: XXX: zone:DMA32 nr_pages_scanned:113 reclaimable:27
[...]
[ 695.215786] vmscan: XXX: zone:DMA32 nr_pages_scanned:140 reclaimable:27
[ 695.215797] vmscan: XXX: zone:DMA32 nr_pages_scanned:141 reclaimable:27
[ 695.215816] vmscan: XXX: zone:DMA32 nr_pages_scanned:144 reclaimable:27
[ 695.215836] vmscan: XXX: zone:DMA32 nr_pages_scanned:150 reclaimable:27
[ 695.215906] test-oleg invoked oom-killer: gfp_mask=0x24201ca(GFP_HIGHUSER_MOVABLE|__GFP_COLD), order=0, oom_score_adj=0
--
Michal Hocko
SUSE Labs
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
2016-05-24 7:16 ` Michal Hocko
@ 2016-05-24 22:43 ` Oleg Nesterov
2016-05-25 12:09 ` Michal Hocko
0 siblings, 1 reply; 14+ messages in thread
From: Oleg Nesterov @ 2016-05-24 22:43 UTC (permalink / raw)
To: Michal Hocko
Cc: Andrew Morton, Andrea Arcangeli, Mel Gorman, linux-kernel, linux-mm
On 05/24, Michal Hocko wrote:
>
> On Mon 23-05-16 17:14:19, Oleg Nesterov wrote:
> > On 05/23, Michal Hocko wrote:
> [...]
> > > Could you add some tracing and see what are the numbers
> > > above?
> >
> > with the patch below I can press Ctrl-C when it hangs, this breaks the
> > endless loop and the output looks like
> >
> > vmscan: ZONE=ffffffff8189f180 0 scanned=0 pages=6
> > vmscan: ZONE=ffffffff8189eb00 0 scanned=1 pages=0
> > ...
> > vmscan: ZONE=ffffffff8189eb00 0 scanned=2 pages=1
> > vmscan: ZONE=ffffffff8189f180 0 scanned=4 pages=6
> > ...
> > vmscan: ZONE=ffffffff8189f180 0 scanned=4 pages=6
> > vmscan: ZONE=ffffffff8189f180 0 scanned=4 pages=6
> >
> > the numbers are always small.
>
> Small but scanned is not 0 and constant which means it either gets reset
> repeatedly (something gets freed) or we have stopped scanning. Which
> pattern can you see? I assume that the swap space is full at the time
> (could you add get_nr_swap_pages() to the output).
no, I tested this without SWAP,
> Also zone->name would
> be better than the pointer.
Yes, forgot to mention, this is DMA32. To remind, only 512m of RAM so
this is natural.
> I am trying to reproduce but your test case always hits the oom killer:
Did you try to run it in a loop? Usually it takes a while before the system
hangs.
> Swap: 138236 57740 80496
perhaps this makes a difference? See above, I have no SWAP.
So. I spent almost the whole day trying to understand whats going on, and
of course I failed.
But. It _seems to me_ that the kernel "leaks" some pages in LRU_INACTIVE_FILE
list because inactive_file_is_low() returns the wrong value. And do not even
ask me why I think so, unlikely I will be able to explain ;) to remind, I never
tried to read vmscan.c before.
But. if I change lruvec_lru_size()
- return zone_page_state(lruvec_zone(lruvec), NR_LRU_BASE + lru);
+ return zone_page_state_snapshot(lruvec_zone(lruvec), NR_LRU_BASE + lru);
the problem goes away too.
To remind, it also goes away if I change calculate_normal_threshold() to return
zero, and it was not clear why. Now we can probably conclude that that this is
because the change obviouslt affects lruvec_lru_size().
Oleg.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
2016-05-24 22:43 ` Oleg Nesterov
@ 2016-05-25 12:09 ` Michal Hocko
2016-05-29 21:25 ` Oleg Nesterov
0 siblings, 1 reply; 14+ messages in thread
From: Michal Hocko @ 2016-05-25 12:09 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Andrew Morton, Andrea Arcangeli, Mel Gorman, linux-kernel, linux-mm
[-- Attachment #1: Type: text/plain, Size: 5683 bytes --]
On Wed 25-05-16 00:43:41, Oleg Nesterov wrote:
> On 05/24, Michal Hocko wrote:
> >
> > On Mon 23-05-16 17:14:19, Oleg Nesterov wrote:
> > > On 05/23, Michal Hocko wrote:
> > [...]
> > > > Could you add some tracing and see what are the numbers
> > > > above?
> > >
> > > with the patch below I can press Ctrl-C when it hangs, this breaks the
> > > endless loop and the output looks like
> > >
> > > vmscan: ZONE=ffffffff8189f180 0 scanned=0 pages=6
> > > vmscan: ZONE=ffffffff8189eb00 0 scanned=1 pages=0
> > > ...
> > > vmscan: ZONE=ffffffff8189eb00 0 scanned=2 pages=1
> > > vmscan: ZONE=ffffffff8189f180 0 scanned=4 pages=6
> > > ...
> > > vmscan: ZONE=ffffffff8189f180 0 scanned=4 pages=6
> > > vmscan: ZONE=ffffffff8189f180 0 scanned=4 pages=6
> > >
> > > the numbers are always small.
> >
> > Small but scanned is not 0 and constant which means it either gets reset
> > repeatedly (something gets freed) or we have stopped scanning. Which
> > pattern can you see? I assume that the swap space is full at the time
> > (could you add get_nr_swap_pages() to the output).
>
> no, I tested this without SWAP,
I have tried that as well but this just hit the OOM almost immediately.
> > I am trying to reproduce but your test case always hits the oom killer:
>
> Did you try to run it in a loop? Usually it takes a while before the system
> hangs.
OK, I wasn't patient enough... Now I can reproduce.
[...]
> So. I spent almost the whole day trying to understand whats going on, and
> of course I failed.
>
> But. It _seems to me_ that the kernel "leaks" some pages in LRU_INACTIVE_FILE
> list because inactive_file_is_low() returns the wrong value. And do not even
> ask me why I think so, unlikely I will be able to explain ;) to remind, I never
> tried to read vmscan.c before.
>
> But. if I change lruvec_lru_size()
>
> - return zone_page_state(lruvec_zone(lruvec), NR_LRU_BASE + lru);
> + return zone_page_state_snapshot(lruvec_zone(lruvec), NR_LRU_BASE + lru);
>
> the problem goes away too.
This is a bit surprising but my testing shows that the result shouldn't
make much difference. I can see some discrepancies between lru_vec size
and zone_reclaimable_pages but they are too small to actually matter.
What I do instead is that there are freed pages on the way and that
always resets the counter. And you can see the number of scanned pages
was really large there. See the attached serial log. So this smells like
the issue I was talking about when mentioning the livelock earlier.
Maybe your change to lruvec_lru_size resp. threshold size just changes
the timing for other operations to hit the race with the free less
likely. Or maybe my debugging output is interfering with the load. Dunno
but it seems like the inherent problem of the oom detection based on the
NR_PAGES_SCANNED to me.
Here is my debugging patch:
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c1069efcc4d7..ac554b633f97 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -834,8 +834,10 @@ static void free_pcppages_bulk(struct zone *zone, int count,
spin_lock(&zone->lock);
nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
- if (nr_scanned)
+ if (nr_scanned) {
+ pr_info("XXX: %s zone:%s clearing %lu pages\n", __FUNCTION__, zone->name, nr_scanned);
__mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
+ }
while (to_free) {
struct page *page;
@@ -888,8 +890,10 @@ static void free_one_page(struct zone *zone,
unsigned long nr_scanned;
spin_lock(&zone->lock);
nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
- if (nr_scanned)
+ if (nr_scanned) {
+ pr_info("XXX: %s zone:%s clearing %lu pages\n", __FUNCTION__, zone->name, nr_scanned);
__mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
+ }
if (unlikely(has_isolate_pageblock(zone) ||
is_migrate_isolate(migratetype))) {
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 142cb61f4822..499a361fe5ad 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1606,6 +1606,8 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
__mod_zone_page_state(zone, NR_ISOLATED_ANON + file, nr_taken);
if (global_reclaim(sc)) {
+ if (!nr_scanned)
+ pr_info("XXXX: %s nothing scanned\n", __FUNCTION__);
__mod_zone_page_state(zone, NR_PAGES_SCANNED, nr_scanned);
if (current_is_kswapd())
__count_zone_vm_events(PGSCAN_KSWAPD, zone, nr_scanned);
@@ -1794,8 +1796,11 @@ static void shrink_active_list(unsigned long nr_to_scan,
nr_taken = isolate_lru_pages(nr_to_scan, lruvec, &l_hold,
&nr_scanned, sc, isolate_mode, lru);
- if (global_reclaim(sc))
+ if (global_reclaim(sc)) {
+ if (!nr_scanned)
+ pr_info("XXXX: %s nothing scanned\n", __FUNCTION__);
__mod_zone_page_state(zone, NR_PAGES_SCANNED, nr_scanned);
+ }
reclaim_stat->recent_scanned[file] += nr_taken;
@@ -2615,8 +2620,15 @@ static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
reclaimable = true;
if (global_reclaim(sc) &&
- !reclaimable && zone_reclaimable(zone))
+ !reclaimable && zone_reclaimable(zone)) {
+ unsigned long file_lru_pages = zone_page_state(zone, NR_INACTIVE_FILE) + zone_page_state(zone, NR_ACTIVE_FILE);
+ pr_info("XXX: %s zone:%s scanned:%lu scanned_snapshot:%lu reclaimable:%lu file_active:%lu file_inactive:%lu isolated:%lu\n",
+ __FUNCTION__, zone->name,
+ zone_page_state(zone, NR_PAGES_SCANNED), zone_page_state_snapshot(zone, NR_PAGES_SCANNED),
+ zone_reclaimable_pages(zone),
+ zone_page_state(zone, NR_ACTIVE_FILE), zone_page_state(zone, NR_INACTIVE_FILE), zone_page_state(zone, NR_ISOLATED_FILE));
reclaimable = true;
+ }
}
/*
--
Michal Hocko
SUSE Labs
[-- Attachment #2: oom-test.qcow_serial.log.gz --]
[-- Type: application/gzip, Size: 407738 bytes --]
^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
2016-05-25 12:09 ` Michal Hocko
@ 2016-05-29 21:25 ` Oleg Nesterov
2016-05-31 12:52 ` Michal Hocko
0 siblings, 1 reply; 14+ messages in thread
From: Oleg Nesterov @ 2016-05-29 21:25 UTC (permalink / raw)
To: Michal Hocko
Cc: Andrew Morton, Andrea Arcangeli, Mel Gorman, linux-kernel, linux-mm
sorry for delay,
On 05/25, Michal Hocko wrote:
>
> On Wed 25-05-16 00:43:41, Oleg Nesterov wrote:
> >
> > But. It _seems to me_ that the kernel "leaks" some pages in LRU_INACTIVE_FILE
> > list because inactive_file_is_low() returns the wrong value. And do not even
> > ask me why I think so, unlikely I will be able to explain ;) to remind, I never
> > tried to read vmscan.c before.
No, this is not because of inactive_file_is_low(), but
> >
> > But. if I change lruvec_lru_size()
> >
> > - return zone_page_state(lruvec_zone(lruvec), NR_LRU_BASE + lru);
> > + return zone_page_state_snapshot(lruvec_zone(lruvec), NR_LRU_BASE + lru);
> >
> > the problem goes away too.
Yes,
> This is a bit surprising but my testing shows that the result shouldn't
> make much difference. I can see some discrepancies between lru_vec size
> and zone_reclaimable_pages but they are too small to actually matter.
Yes, the difference is small but it does matter.
I do not pretend I understand this all, but finally it seems I understand
whats going on on my system when it hangs. At least, why the change in
lruvec_lru_size() or calculate_normal_threshold() makes a difference.
This single change in get_scan_count() under for_each_evictable_lru() loop
- size = lruvec_lru_size(lruvec, lru);
+ size = zone_page_state_snapshot(lruvec_zone(lruvec), NR_LRU_BASE + lru);
fixes the problem too.
Without this change shrink*() continues to scan the LRU_ACTIVE_FILE list
while it is empty. LRU_INACTIVE_FILE is not empty (just a few pages) but
we do not even try to scan it, lruvec_lru_size() returns zero.
Then later we recheck zone_reclaimable() and it notices the INACTIVE_FILE
counter because it uses the _snapshot variant, this leads to livelock.
I guess this doesn't really matter, but in my particular case these
ACTIVE/INACTIVE counters were screwed by the recent putback_inactive_pages()
logic. The pages we "leak" in INACTIVE list were recently moved from ACTIVE
to INACTIVE list, and this updated only the per-cpu ->vm_stat_diff[] counters,
so the "non snapshot" lruvec_lru_size() in get_scan_count() sees the "old"
numbers.
I even added more printk's, and yes when the system hangs I have something
like, say,
->vm_stat[ACTIVE] = NR; // small number
->vm_stat_diff[ACTIVE] = -NR; // so it is actually zero but
// get_scan_count() sees NR
->vm_stat[INACTIVE] = 0; // this is what get_scan_count() sees
->vm_stat_diff[INACTIVE] = NR; // and this is what zone_reclaimable()
Oleg.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
2016-05-29 21:25 ` Oleg Nesterov
@ 2016-05-31 12:52 ` Michal Hocko
2016-05-31 23:56 ` Oleg Nesterov
0 siblings, 1 reply; 14+ messages in thread
From: Michal Hocko @ 2016-05-31 12:52 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Andrew Morton, Andrea Arcangeli, Mel Gorman, linux-kernel, linux-mm
On Sun 29-05-16 23:25:40, Oleg Nesterov wrote:
> sorry for delay,
>
> On 05/25, Michal Hocko wrote:
[...]
> > This is a bit surprising but my testing shows that the result shouldn't
> > make much difference. I can see some discrepancies between lru_vec size
> > and zone_reclaimable_pages but they are too small to actually matter.
>
> Yes, the difference is small but it does matter.
>
> I do not pretend I understand this all, but finally it seems I understand
> whats going on on my system when it hangs. At least, why the change in
> lruvec_lru_size() or calculate_normal_threshold() makes a difference.
>
> This single change in get_scan_count() under for_each_evictable_lru() loop
>
> - size = lruvec_lru_size(lruvec, lru);
> + size = zone_page_state_snapshot(lruvec_zone(lruvec), NR_LRU_BASE + lru);
>
> fixes the problem too.
>
> Without this change shrink*() continues to scan the LRU_ACTIVE_FILE list
> while it is empty. LRU_INACTIVE_FILE is not empty (just a few pages) but
> we do not even try to scan it, lruvec_lru_size() returns zero.
OK, you seem to be really seeing a different issue than me. My debugging
patch was showing when nothing was really isolated from the LRU lists
(both for shrink_{in}active_list.
> Then later we recheck zone_reclaimable() and it notices the INACTIVE_FILE
> counter because it uses the _snapshot variant, this leads to livelock.
>
> I guess this doesn't really matter, but in my particular case these
> ACTIVE/INACTIVE counters were screwed by the recent putback_inactive_pages()
> logic. The pages we "leak" in INACTIVE list were recently moved from ACTIVE
> to INACTIVE list, and this updated only the per-cpu ->vm_stat_diff[] counters,
> so the "non snapshot" lruvec_lru_size() in get_scan_count() sees the "old"
> numbers.
Hmm. I am not really sure we can use the _snapshot version in lruvec_lru_size.
It is called also outise of slow paths (like add_to_page_cache_lru).
Maybe a path like below would be acceptable for stable trees.
But I am thinking whether we should simply revert 0db2cb8da89d ("mm,
vmscan: make zone_reclaimable_pages more precise") in 4.6 stable tree.
Does that help as well? The patch is certainly needed for the oom
detection rework but it got merged one release cycle earlier.
---
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 3388ccbab7d6..9f46a29c06b6 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -764,7 +764,8 @@ static inline struct zone *lruvec_zone(struct lruvec *lruvec)
#endif
}
-extern unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru);
+extern unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru,
+ bool precise);
#ifdef CONFIG_HAVE_MEMORY_PRESENT
void memory_present(int nid, unsigned long start, unsigned long end);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index c4a2f4512fca..84420045090b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -213,11 +213,13 @@ bool zone_reclaimable(struct zone *zone)
zone_reclaimable_pages(zone) * 6;
}
-unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru)
+unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, bool precise)
{
if (!mem_cgroup_disabled())
return mem_cgroup_get_lru_size(lruvec, lru);
+ if (precise)
+ return zone_page_state_snapshot(lruvec_zone(lruvec), NR_LRU_BASE + lru);
return zone_page_state(lruvec_zone(lruvec), NR_LRU_BASE + lru);
}
@@ -1902,8 +1904,8 @@ static bool inactive_list_is_low(struct lruvec *lruvec, bool file)
if (!file && !total_swap_pages)
return false;
- inactive = lruvec_lru_size(lruvec, file * LRU_FILE);
- active = lruvec_lru_size(lruvec, file * LRU_FILE + LRU_ACTIVE);
+ inactive = lruvec_lru_size(lruvec, file * LRU_FILE, true);
+ active = lruvec_lru_size(lruvec, file * LRU_FILE + LRU_ACTIVE, true);
gb = (inactive + active) >> (30 - PAGE_SHIFT);
if (gb)
@@ -2040,7 +2042,7 @@ static void get_scan_count(struct lruvec *lruvec, struct mem_cgroup *memcg,
* system is under heavy pressure.
*/
if (!inactive_list_is_low(lruvec, true) &&
- lruvec_lru_size(lruvec, LRU_INACTIVE_FILE) >> sc->priority) {
+ lruvec_lru_size(lruvec, LRU_INACTIVE_FILE, true) >> sc->priority) {
scan_balance = SCAN_FILE;
goto out;
}
@@ -2066,10 +2068,10 @@ static void get_scan_count(struct lruvec *lruvec, struct mem_cgroup *memcg,
* anon in [0], file in [1]
*/
- anon = lruvec_lru_size(lruvec, LRU_ACTIVE_ANON) +
- lruvec_lru_size(lruvec, LRU_INACTIVE_ANON);
- file = lruvec_lru_size(lruvec, LRU_ACTIVE_FILE) +
- lruvec_lru_size(lruvec, LRU_INACTIVE_FILE);
+ anon = lruvec_lru_size(lruvec, LRU_ACTIVE_ANON, true) +
+ lruvec_lru_size(lruvec, LRU_INACTIVE_ANON, true);
+ file = lruvec_lru_size(lruvec, LRU_ACTIVE_FILE, true) +
+ lruvec_lru_size(lruvec, LRU_INACTIVE_FILE, true);
spin_lock_irq(&zone->lru_lock);
if (unlikely(reclaim_stat->recent_scanned[0] > anon / 4)) {
@@ -2107,7 +2109,7 @@ static void get_scan_count(struct lruvec *lruvec, struct mem_cgroup *memcg,
unsigned long size;
unsigned long scan;
- size = lruvec_lru_size(lruvec, lru);
+ size = lruvec_lru_size(lruvec, lru, true);
scan = size >> sc->priority;
if (!scan && pass && force_scan)
diff --git a/mm/workingset.c b/mm/workingset.c
index 8a75f8d2916a..509cdf7a6fc9 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -269,7 +269,7 @@ bool workingset_refault(void *shadow)
}
lruvec = mem_cgroup_zone_lruvec(zone, memcg);
refault = atomic_long_read(&lruvec->inactive_age);
- active_file = lruvec_lru_size(lruvec, LRU_ACTIVE_FILE);
+ active_file = lruvec_lru_size(lruvec, LRU_ACTIVE_FILE, false);
rcu_read_unlock();
/*
--
Michal Hocko
SUSE Labs
^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
2016-05-31 12:52 ` Michal Hocko
@ 2016-05-31 23:56 ` Oleg Nesterov
2016-06-01 10:00 ` Michal Hocko
0 siblings, 1 reply; 14+ messages in thread
From: Oleg Nesterov @ 2016-05-31 23:56 UTC (permalink / raw)
To: Michal Hocko
Cc: Andrew Morton, Andrea Arcangeli, Mel Gorman, linux-kernel, linux-mm
On 05/31, Michal Hocko wrote:
>
> On Sun 29-05-16 23:25:40, Oleg Nesterov wrote:
> >
> > This single change in get_scan_count() under for_each_evictable_lru() loop
> >
> > - size = lruvec_lru_size(lruvec, lru);
> > + size = zone_page_state_snapshot(lruvec_zone(lruvec), NR_LRU_BASE + lru);
> >
> > fixes the problem too.
> >
> > Without this change shrink*() continues to scan the LRU_ACTIVE_FILE list
> > while it is empty. LRU_INACTIVE_FILE is not empty (just a few pages) but
> > we do not even try to scan it, lruvec_lru_size() returns zero.
>
> OK, you seem to be really seeing a different issue than me.
quite possibly, but
> My debugging
> patch was showing when nothing was really isolated from the LRU lists
> (both for shrink_{in}active_list.
in my debugging session too. LRU_ACTIVE_FILE was empty, so there is nothing to
isolate even if shrink_active_list() is (wrongly called) with nr_to_scan != 0.
LRU_INACTIVE_FILE is not empty but it is not scanned because nr_to_scan == 0.
But I am afraid I misunderstood you, and you meant something else.
> > Then later we recheck zone_reclaimable() and it notices the INACTIVE_FILE
> > counter because it uses the _snapshot variant, this leads to livelock.
> >
> > I guess this doesn't really matter, but in my particular case these
> > ACTIVE/INACTIVE counters were screwed by the recent putback_inactive_pages()
> > logic. The pages we "leak" in INACTIVE list were recently moved from ACTIVE
> > to INACTIVE list, and this updated only the per-cpu ->vm_stat_diff[] counters,
> > so the "non snapshot" lruvec_lru_size() in get_scan_count() sees the "old"
> > numbers.
>
> Hmm. I am not really sure we can use the _snapshot version in lruvec_lru_size.
Yes, yes, I understand,
> But I am thinking whether we should simply revert 0db2cb8da89d ("mm,
> vmscan: make zone_reclaimable_pages more precise") in 4.6 stable tree.
> Does that help as well?
I'll test this tomorrow, but even if it helps I am not sure... Yes, this
way zone_reclaimable() and get_scan_count() will see the same numbers, but
how this can help to make zone_reclaimable() == F at the end?
Again, suppose that (say) ACTIVE list is empty but zone->vm_stat != 0
because there is something in per-cpu counter (so that _snapshot == 0).
This means that we sill continue to try to scan this list for no reason.
But Michal, let me repeat that I do not understand this code, so I can
be easily wrong.
Oleg.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
2016-05-31 23:56 ` Oleg Nesterov
@ 2016-06-01 10:00 ` Michal Hocko
2016-06-01 21:38 ` Oleg Nesterov
0 siblings, 1 reply; 14+ messages in thread
From: Michal Hocko @ 2016-06-01 10:00 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Andrew Morton, Andrea Arcangeli, Mel Gorman, linux-kernel, linux-mm
On Wed 01-06-16 01:56:26, Oleg Nesterov wrote:
> On 05/31, Michal Hocko wrote:
> >
> > On Sun 29-05-16 23:25:40, Oleg Nesterov wrote:
> > >
> > > This single change in get_scan_count() under for_each_evictable_lru() loop
> > >
> > > - size = lruvec_lru_size(lruvec, lru);
> > > + size = zone_page_state_snapshot(lruvec_zone(lruvec), NR_LRU_BASE + lru);
> > >
> > > fixes the problem too.
> > >
> > > Without this change shrink*() continues to scan the LRU_ACTIVE_FILE list
> > > while it is empty. LRU_INACTIVE_FILE is not empty (just a few pages) but
> > > we do not even try to scan it, lruvec_lru_size() returns zero.
> >
> > OK, you seem to be really seeing a different issue than me.
>
> quite possibly, but
>
> > My debugging
> > patch was showing when nothing was really isolated from the LRU lists
> > (both for shrink_{in}active_list.
>
> in my debugging session too. LRU_ACTIVE_FILE was empty, so there is nothing to
> isolate even if shrink_active_list() is (wrongly called) with nr_to_scan != 0.
> LRU_INACTIVE_FILE is not empty but it is not scanned because nr_to_scan == 0.
>
> But I am afraid I misunderstood you, and you meant something else.
What I wanted to say is that my debugging hasn't shown a single case
when nothing would be isolated. Which seems to be the case for you.
[...]
> > But I am thinking whether we should simply revert 0db2cb8da89d ("mm,
> > vmscan: make zone_reclaimable_pages more precise") in 4.6 stable tree.
> > Does that help as well?
>
> I'll test this tomorrow, but even if it helps I am not sure... Yes, this
> way zone_reclaimable() and get_scan_count() will see the same numbers, but
> how this can help to make zone_reclaimable() == F at the end?
It won't in some cases. And that has been the case for ages so I do not
think we need any steps for the stable. What meant to address is a
potential regression caused by 0db2cb8da89d which would make this more
likely because of the mismatch because the patch really makes much more
sense for the oom detection rework which really wants more precise
numbers. If the revert doesn't help then I would just leave it as it is
and just note that the zone_reclaimable was a bad decision which
fortunatelly didn't blow up that often...
Thanks
--
Michal Hocko
SUSE Labs
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
2016-06-01 10:00 ` Michal Hocko
@ 2016-06-01 21:38 ` Oleg Nesterov
2016-06-02 15:11 ` Michal Hocko
0 siblings, 1 reply; 14+ messages in thread
From: Oleg Nesterov @ 2016-06-01 21:38 UTC (permalink / raw)
To: Michal Hocko
Cc: Andrew Morton, Andrea Arcangeli, Mel Gorman, linux-kernel, linux-mm
On 06/01, Michal Hocko wrote:
>
> On Wed 01-06-16 01:56:26, Oleg Nesterov wrote:
> > On 05/31, Michal Hocko wrote:
> > >
> > > On Sun 29-05-16 23:25:40, Oleg Nesterov wrote:
> > > >
> > > > This single change in get_scan_count() under for_each_evictable_lru() loop
> > > >
> > > > - size = lruvec_lru_size(lruvec, lru);
> > > > + size = zone_page_state_snapshot(lruvec_zone(lruvec), NR_LRU_BASE + lru);
> > > >
> > > > fixes the problem too.
> > > >
> > > > Without this change shrink*() continues to scan the LRU_ACTIVE_FILE list
> > > > while it is empty. LRU_INACTIVE_FILE is not empty (just a few pages) but
> > > > we do not even try to scan it, lruvec_lru_size() returns zero.
> > >
> > > OK, you seem to be really seeing a different issue than me.
> >
> > quite possibly, but
> >
> > > My debugging
> > > patch was showing when nothing was really isolated from the LRU lists
> > > (both for shrink_{in}active_list.
> >
> > in my debugging session too. LRU_ACTIVE_FILE was empty, so there is nothing to
> > isolate even if shrink_active_list() is (wrongly called) with nr_to_scan != 0.
> > LRU_INACTIVE_FILE is not empty but it is not scanned because nr_to_scan == 0.
> >
> > But I am afraid I misunderstood you, and you meant something else.
>
> What I wanted to say is that my debugging hasn't shown a single case
> when nothing would be isolated. Which seems to be the case for you.
Ah, got it, thanks. Yes, I see that there is no "nothing scanned" in
oom-test.qcow_serial.log.gz from http://marc.info/?l=linux-kernel&m=146417822608902
you sent. I applied this patch and I do see "nothing scanned".
But, unlike you, I do not see the messages from free-pages... perhaps you
have more active tasks. To remind, I tested this with the single user-space
process, /bin/sh running with pid==1, then I did "while true; do ./oom; done".
So of course I do not know if you see another issue or the same, but now I am
wondering if the change in get_scan_count() above fixes the problem for you.
Probably not, but the fact you do not see "nothing scanned" can't prove this,
it is possible that shrink_*_list() was not called because vm_stat == 0 but
zone_reclaimable() sees the per-cpu counter. In this case 0db2cb8da89d can
make a difference, but see below.
> > > But I am thinking whether we should simply revert 0db2cb8da89d ("mm,
> > > vmscan: make zone_reclaimable_pages more precise") in 4.6 stable tree.
> > > Does that help as well?
> >
> > I'll test this tomorrow,
So it doesn't help.
> but even if it helps I am not sure... Yes, this
> > way zone_reclaimable() and get_scan_count() will see the same numbers, but
> > how this can help to make zone_reclaimable() == F at the end?
>
> It won't in some cases.
And unless I am notally confused hit exactly this case.
> And that has been the case for ages so I do not
> think we need any steps for the stable.
OK, agreed.
> What meant to address is a
> potential regression caused by 0db2cb8da89d which would make this more
> likely because of the mismatch
Again, I can be easily wrong, but I do not see how 0db2cb8da89d could make
the things worse...
Unless both get_scan_count() and zone_reclaimable() use "snapshot" variant,
we can't guarantee zone_reclaimable() becomes false. The fact that they see
different numbers (after 0db2cb8da89d) doesn't really matter.
Anyway, this was already fixed, so lets forget it ;)
Oleg.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: zone_reclaimable() leads to livelock in __alloc_pages_slowpath()
2016-06-01 21:38 ` Oleg Nesterov
@ 2016-06-02 15:11 ` Michal Hocko
0 siblings, 0 replies; 14+ messages in thread
From: Michal Hocko @ 2016-06-02 15:11 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Andrew Morton, Andrea Arcangeli, Mel Gorman, linux-kernel, linux-mm
On Wed 01-06-16 23:38:30, Oleg Nesterov wrote:
> On 06/01, Michal Hocko wrote:
> >
> > On Wed 01-06-16 01:56:26, Oleg Nesterov wrote:
> > > On 05/31, Michal Hocko wrote:
> > > >
> > > > On Sun 29-05-16 23:25:40, Oleg Nesterov wrote:
> > > > >
> > > > > This single change in get_scan_count() under for_each_evictable_lru() loop
> > > > >
> > > > > - size = lruvec_lru_size(lruvec, lru);
> > > > > + size = zone_page_state_snapshot(lruvec_zone(lruvec), NR_LRU_BASE + lru);
> > > > >
> > > > > fixes the problem too.
> > > > >
> > > > > Without this change shrink*() continues to scan the LRU_ACTIVE_FILE list
> > > > > while it is empty. LRU_INACTIVE_FILE is not empty (just a few pages) but
> > > > > we do not even try to scan it, lruvec_lru_size() returns zero.
> > > >
> > > > OK, you seem to be really seeing a different issue than me.
> > >
> > > quite possibly, but
> > >
> > > > My debugging
> > > > patch was showing when nothing was really isolated from the LRU lists
> > > > (both for shrink_{in}active_list.
> > >
> > > in my debugging session too. LRU_ACTIVE_FILE was empty, so there is nothing to
> > > isolate even if shrink_active_list() is (wrongly called) with nr_to_scan != 0.
> > > LRU_INACTIVE_FILE is not empty but it is not scanned because nr_to_scan == 0.
> > >
> > > But I am afraid I misunderstood you, and you meant something else.
> >
> > What I wanted to say is that my debugging hasn't shown a single case
> > when nothing would be isolated. Which seems to be the case for you.
>
> Ah, got it, thanks. Yes, I see that there is no "nothing scanned" in
> oom-test.qcow_serial.log.gz from http://marc.info/?l=linux-kernel&m=146417822608902
> you sent. I applied this patch and I do see "nothing scanned".
>
> But, unlike you, I do not see the messages from free-pages... perhaps you
> have more active tasks. To remind, I tested this with the single user-space
> process, /bin/sh running with pid==1, then I did "while true; do ./oom; done".
Well, I was booting into a standard init which will have a couple of
processes. So yes this would make a slight difference.
> So of course I do not know if you see another issue or the same, but now I am
> wondering if the change in get_scan_count() above fixes the problem for you.
I have played with it but the interfering freed pages just ruined the
whole zone_reclaimable expectations.
> Probably not, but the fact you do not see "nothing scanned" can't prove this,
> it is possible that shrink_*_list() was not called because vm_stat == 0 but
> zone_reclaimable() sees the per-cpu counter. In this case 0db2cb8da89d can
> make a difference, but see below.
>
> > > > But I am thinking whether we should simply revert 0db2cb8da89d ("mm,
> > > > vmscan: make zone_reclaimable_pages more precise") in 4.6 stable tree.
> > > > Does that help as well?
> > >
> > > I'll test this tomorrow,
>
> So it doesn't help.
OK, so we at least know this is not a regression.
> > but even if it helps I am not sure... Yes, this
> > > way zone_reclaimable() and get_scan_count() will see the same numbers, but
> > > how this can help to make zone_reclaimable() == F at the end?
> >
> > It won't in some cases.
>
> And unless I am notally confused hit exactly this case.
>
> > And that has been the case for ages so I do not
> > think we need any steps for the stable.
>
> OK, agreed.
>
> > What meant to address is a
> > potential regression caused by 0db2cb8da89d which would make this more
> > likely because of the mismatch
>
> Again, I can be easily wrong, but I do not see how 0db2cb8da89d could make
> the things worse...
>
> Unless both get_scan_count() and zone_reclaimable() use "snapshot" variant,
> we can't guarantee zone_reclaimable() becomes false. The fact that they see
> different numbers (after 0db2cb8da89d) doesn't really matter.
>
> Anyway, this was already fixed, so lets forget it ;)
Yes, especially as this doesn't seem to be a regression.
Thanks for your effort anyway.
--
Michal Hocko
SUSE Labs
^ permalink raw reply [flat|nested] 14+ messages in thread
end of thread, other threads:[~2016-06-02 15:11 UTC | newest]
Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-05-20 20:28 zone_reclaimable() leads to livelock in __alloc_pages_slowpath() Oleg Nesterov
2016-05-21 4:07 ` Tetsuo Handa
2016-05-22 21:17 ` Oleg Nesterov
2016-05-23 7:29 ` Michal Hocko
2016-05-23 15:14 ` Oleg Nesterov
2016-05-24 7:16 ` Michal Hocko
2016-05-24 22:43 ` Oleg Nesterov
2016-05-25 12:09 ` Michal Hocko
2016-05-29 21:25 ` Oleg Nesterov
2016-05-31 12:52 ` Michal Hocko
2016-05-31 23:56 ` Oleg Nesterov
2016-06-01 10:00 ` Michal Hocko
2016-06-01 21:38 ` Oleg Nesterov
2016-06-02 15:11 ` Michal Hocko
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