* John Magolske <listm...@b79.net> [120525 17:13]: > For a while now I've been experiencing a strange behavior where there > are frequent and regular "freezes" when typing or issuing commands > in the shell. All of a sudden I'll find myself "blind-typing" for 3 > seconds or so before a backlog of characters burst onto the screen.
Ok, so I opened up htop to look up & kill off non-essential daemons, adjusted vm.dirty_ratio and vm.dirty_background_ratio [1], tried changing and tuning the IO scheduler [2] (switched from cfq to deadline) ... all to no avail, still these infernal 3-second freezes. Although I mentioned in my last email this behavior showed up while plugged into AC power, it turns out that was the one rare exception. By and large, I only see these freezes while running on battery. And it does seem to correlate with the hard disk spinning up. But why should, for example, scrolling the selector bar up in Mutt require the hard disk to spin up first? (eg, hold down up-arrow key, nothing happens, hard disk spins up, THEN the selector bar jumps up 5 lines or so after a 3-second pause). I'm thinking this must have to do with the graphics somehow. I'm often listening to music during all this and I *never* hear the audio skip. As per `hwinfo --gfxcard` : Model: "Intel Mobile 4 Series Chipset Integrated Graphics Controller" Vendor: pci 0x8086 "Intel Corporation" Device: pci 0x2a42 "Mobile 4 Series Chipset Integrated Graphics Controller" Driver: "i915" Driver Modules: "drm" Driver Info #0: Driver Status: i915 is active Driver Activation Cmd: "modprobe i915" Even in doing something as simple as moving the text cursor around while holding down an arrow key, there'll be these periodic 3-4 second freezes, after which the cursor will jump ahead the distance it would've traveled in that time. I'm beginning to wonder if this is just normal behavior that everyone puts up with, but I find that hard to believe. I have laptop-mode enabled...maybe try messing around with the settings in laptop-mode.conf next? Any suggestions would be greatly appreciated. [1] An older message about an older kernel (I'm on 3.2.0-2-686-pae), but the description sounds a lot like what I'm seeing: http://forum.soft32.com/linux/multi-freezes-current-GIT-ftopict344063.html tried looking at these too: http://www.linuxinsight.com/proc_sys_vm_hierarchy.html http://www.sysxperts.com/home/announce/vmdirtyratioandvmdirtybackgroundratio http://rackerhacker.com/2008/08/07/reduce-disk-io-for-small-reads-using-memory/ [2] This is about dealing with the interactive performance when booting from a flash drive (I'm running off a spinning disk), but has some interesting discussion re tuning the scheduler: http://hardware.slashdot.org/comments.pl?sid=582327&threshold=-1&commentsort=0&mode=nested&no_d2=1&cid=23778109 Regards, John -- John Magolske http://B79.net/contact -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20120601161142.ga18...@s70206.gridserver.com