What's the value of `vm.dirty_writeback_centisecs` ?, ie. $ sysctl vm.dirty_writeback_centisecs
try setting it to 0 to disable it, ie. `$ sudo sysctl -w vm.dirty_writeback_centisecs=0` I found that this helps my network transfer not stall/stop at all(for a few seconds when that is =1000 for example) while some kinda of non- async `sync`(command)-like flushing is going on periodically while transferring GiB of data files from sftp to SSD!(via Midnight Commander, on a link limited to 10MiB per second) vm.dirty_writeback_centisecs is how often the pdflush/flush/kdmflush processes wake up and check to see if work needs to be done. Coupled with the above I've been using another value: `vm.dirty_expire_centisecs=1000` for both cases (when stall and not stall), so this one remained fixed to =1000. vm.dirty_expire_centisecs is how long something can be in cache before it needs to be written. In this case it's 1 seconds. When the pdflush/flush/kdmflush processes kick in they will check to see how old a dirty page is, and if it's older than this value it'll be written asynchronously to disk. Since holding a dirty page in memory is unsafe this is also a safeguard against data loss. Well, with the above, at least I'm not experiencing network stalls when copying GiB of data via Midnight Commander's sftp to my SSD until some kernel-caused sync-ing is completed in the background. I don't know if this will work for others, but if curious about any of my other (sysctl)settings, they should be available for perusing [here](https://github.com/howaboutsynergy/q1q/tree/0a2cd4ba658067140d3f0ae89a0897af54da52a4/OSes/archlinux/etc/sysctl.d) -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/595047 Title: Frequent swapping causes system to hang Status in Linux: Fix Released Status in linux package in Ubuntu: Incomplete Bug description: Periodically I notice my system slows to a near stand still, and the hard drive light is constantly going. This seems to be a massive amount of disk i/o and it lasts for a long time (lets say 30 mins to put a number on it). I installed and ran iotop (`iotop -a`) and it seems to point to jbd2. From what I can see jbd2 is related to ext4 journaling, but I cannot figure out how to kill this operation. It might even be a red herring because I have also stopped the disk activity by kill either chromium or firefox. I need to understand what else I can do to troubleshoot this. $ lsb_release -rd Description: Ubuntu maverick (development branch) Release: 10.10 Up-to-date as of 16th June 2010. --- AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23. AplayDevices: **** List of PLAYBACK Hardware Devices **** card 0: Intel [HDA Intel], device 0: ALC272X Analog [ALC272X Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 Architecture: i386 ArecordDevices: **** List of CAPTURE Hardware Devices **** card 0: Intel [HDA Intel], device 0: ALC272X Analog [ALC272X Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: pgoodall 1372 F.... pulseaudio CRDA: Error: [Errno 2] No such file or directory Card0.Amixer.info: Card hw:0 'Intel'/'HDA Intel at 0x56440000 irq 44' Mixer name : 'Realtek ALC272X' Components : 'HDA:10ec0272,1025022c,00100001' Controls : 14 Simple ctrls : 8 DistroRelease: Ubuntu 10.10 Frequency: Once a day. HibernationDevice: RESUME=UUID=145f27a9-859a-4987-8132-ac878c832747 InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Alpha i386 (20100602.2) MachineType: Acer AO531h Package: linux (not installed) ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.35-6-generic root=UUID=11f96f8b-5e04-4e20-a201-0fa5d0fc07fa ro quiet splash ProcEnviron: PATH=(custom, user) LANG=en_GB.utf8 SHELL=/bin/bash ProcVersionSignature: Ubuntu 2.6.35-6.9-generic 2.6.35-rc3 Regression: Yes RelatedPackageVersions: linux-firmware 1.37 Reproducible: No Tags: maverick ubuntu-une kconfig regression-potential needs-upstream-testing Uname: Linux 2.6.35-6-generic i686 UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare dmi.bios.date: 12/22/2009 dmi.bios.vendor: Acer dmi.bios.version: v0.3304 dmi.board.asset.tag: Base Board Asset Tag dmi.board.vendor: Acer dmi.board.version: Base Board Version dmi.chassis.type: 1 dmi.chassis.vendor: Chassis Manufacturer dmi.chassis.version: Chassis Version dmi.modalias: dmi:bvnAcer:bvrv0.3304:bd12/22/2009:svnAcer:pnAO531h:pvr1:rvnAcer:rn:rvrBaseBoardVersion:cvnChassisManufacturer:ct1:cvrChassisVersion: dmi.product.name: AO531h dmi.product.version: 1 dmi.sys.vendor: Acer To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/595047/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
