Comment 150 for bug 1518457

Dear Dan,

I am not sure you are mailing the right person. Anyway, the issue still
arises when copying large files from a FAT drive to an EXT one. kswapd uses
all available CPU power (but leaves much of the RAM unused) and copy
throughput declines.

Anyway, I solved the problem by transferring my external drive to an EXT4
filesystem, at the expense of interoperability.

Best

Le jeu. 26 oct. 2017 à 13:26, Dan Streetman <email address hidden> a
écrit :

> this bug is fix released. please open a new bug.
>
> note that you may just have been out of memory.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1518457
>
> Title:
> kswapd0 100% CPU usage
>
> Status in Linux:
> Unknown
> Status in linux package in Ubuntu:
> Fix Released
> Status in linux source package in Xenial:
> Fix Released
> Status in linux source package in Yakkety:
> Fix Released
>
> Bug description:
> As per bug 721896 and various others:
>
> I'm on an AWS t2.micro instance (Xeon E5-2670, 991MiB of memory).
> Occasionally (about once a day), kswapd0 falls into a busy loop and
> spins on 100% CPU usage indefinitely. This can be provoked by
> copying/writing large files (e.g. dding a 256MB file), but it happens
> occasionally otherwise. System memory usage (not including
> buffers/caches) currently sits at 36%, which is typical[1]. Initially
> I had no swap space configured; I've since tried enabling a 256MB swap
> file, but the problem continues to occur and no swap space is used.
> The system can be recovered with `echo 1 > /proc/sys/vm/drop_caches`.
>
> Happy to provide further information/take further debugging actions.
>
>
> [1] Full output from `free`:
> total used free shared buffers cached
> Mem: 1014936 483448 531488 28556 9756 112700
> -/+ buffers/cache: 360992 653944
> Swap: 262140 0 262140
>
> ProblemType: Bug
> DistroRelease: Ubuntu 15.10
> Package: linux-image-4.2.0-18-generic 4.2.0-18.22
> ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
> Uname: Linux 4.2.0-18-generic x86_64
> AlsaDevices:
> total 0
> crw-rw---- 1 root audio 116, 1 Nov 19 19:40 seq
> crw-rw---- 1 root audio 116, 33 Nov 19 19:40 timer
> AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
> ApportVersion: 2.19.1-0ubuntu5
> Architecture: amd64
> ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
> AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq',
> '/dev/snd/timer'] failed with exit code 1:
> CRDA: N/A
> Date: Fri Nov 20 20:44:30 2015
> Ec2AMI: ami-1c552a76
> Ec2AMIManifest: (unknown)
> Ec2AvailabilityZone: us-east-1d
> Ec2InstanceType: t2.micro
> Ec2Kernel: unavailable
> Ec2Ramdisk: unavailable
> IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
> Lsusb: Error: command ['lsusb'] failed with exit code 1: unable to
> initialize libusb: -99
> MachineType: Xen HVM domU
> PciMultimedia:
>
> ProcEnviron:
> TERM=screen
> PATH=(custom, no user)
> LANG=en_US.UTF-8
> SHELL=/bin/bash
> ProcFB: 0 xen
> ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic
> root=UUID=35bc01f4-4602-4823-976e-508edef899df ro console=tty1
> console=ttyS0 net.ifnames=0
> RelatedPackageVersions:
> linux-restricted-modules-4.2.0-18-generic N/A
> linux-backports-modules-4.2.0-18-generic N/A
> linux-firmware N/A
> RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
> SourcePackage: linux
> UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
> UpgradeStatus: No upgrade log present (probably fresh install)
> dmi.bios.date: 05/06/2015
> dmi.bios.vendor: Xen
> dmi.bios.version: 4.2.amazon
> dmi.chassis.type: 1
> dmi.chassis.vendor: Xen
> dmi.modalias:
> dmi:bvnXen:bvr4.2.amazon:bd05/06/2015:svnXen:pnHVMdomU:pvr4.2.amazon:cvnXen:ct1:cvr:
> dmi.product.name: HVM domU
> dmi.product.version: 4.2.amazon
> dmi.sys.vendor: Xen
>
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