Author Archives: lee

rtorrent sequential download

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Patch libtorrent

diff --git a/src/download/chunk_selector.cc b/src/download/chunk_selector.cc
index 850fec0f..248a29f9 100644
--- a/src/download/chunk_selector.cc
+++ b/src/download/chunk_selector.cc
@@ -82,7 +82,7 @@ ChunkSelector::update_priorities() {
   m_sharedQueue.clear();
 
   if (m_position == invalid_chunk)
-    m_position = random() % size();
+    m_position = 0;
 
   advance_position();
 }
@@ -100,14 +100,6 @@ ChunkSelector::find(PeerChunks* pc, __UNUSED bool highPriority) {
   // set.
   rak::partial_queue* queue = pc->is_seeder() ? &m_sharedQueue : pc->download_cache();
 
-  // Randomize position on average every 16 chunks to prevent
-  // inefficient distribution with a slow seed and fast peers
-  // all arriving at the same position.
-  if ((random() & 63) == 0) {
-    m_position = random() % size();
-    queue->clear();
-  }
-
   if (queue->is_enabled()) {
 
     // First check the cached queue.

Libvirt – Auto resize does not work on most linux guests

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It is left to the DM to resize after being informed by libvirt there has been a change. Many don’t.
Poor design decision IMHO. 

xrandr --output Virtual-1 --auto

Will resize to the window size you have chosen. The Virtual-1 part might need adjusting. You can find out by using

xrandr

on it’s own. In the case of a Manjero VM I just installed

$ xrandr
Screen 0: minimum 320 x 200, current 1256 x 869, maximum 8192 x 8192
Virtual-1 connected primary 1256x869+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1256x869      59.98*+
   2560x1600     59.99    59.97  ....................................

So it’s Virtual-1.

Make a script and link it to a hotkey and it’s less of an annoyance.

Note: spice-vdagent may need to be installed and running for this to work ?

Bezel correction and multiple displays with Nvidia driver on Linux – Metamode seems to be ignored

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In theory it should be as easy as using offsets in a ‘metamode’ line. in he screen section of xorg.conf eg.

	Option         "metamodes" "DP-0: 1920x1080_75 +0+0,DP-2: 1920x1080_75 +1962+0, DP-4: 1920x1080_75 +3924+0

Where +0+0 , +1962+0 and +3924+0 is adding 42 pixels between monitors to account for the size of my bezels. But it doesn’t work. The metamode line is ignored and the nvidia driver make it’s own metamode line, as seen in Xorg.log

[ 40517.093] (**) NVIDIA(0): Option "MetaModes" "DP-2: 1920x1080_75 +1920+0, DP-0: 1920x1080_75 +0+0, DP-4: 1920x1080_75 +3840+0"

I can change the absolute positions in the nvidia-settings GUI. Press apply and it works. I have my bezel correction. But then click ‘Save to Xconfig file’, Fire up an xserver with that .conf and it overrides the custom metamode again.

Work around:

Use nvidia-settings gui to position the displays with the offsets you want. Click apply.
On the command line
nvidia-settings –query Currentmetamode
Which gave me

Attribute ‘CurrentMetaMode’ (gent:1.0): id=50, switchable=no, source=nv-control :: DPY-3: 1920x1080_75 @1920x1080
+1962+0 {ViewPortIn=1920x1080, ViewPortOut=1920x1080+0+0}, DPY-0: 1920x1080_75 @1920x1080 +0+0
{ViewPortIn=1920x1080, ViewPortOut=1920x1080+0+0}, DPY-5: 1920x1080_75 @1920x1080 +3924+0 {ViewPortIn=1920x1080,
ViewPortOut=1920x1080+0+0}

You’ll need to clean up newlines and extra white space so its all on one line . Get rid of the “(gent:1.0): id=50, switchable=no, source=nv-control ::” bit (when I didn’t the command succeeded but I lost my middle display). Get rid of Attribute, put an = after ‘CurrentMetaMode’ and double quotes around every following, and nvidia-settings –assign at the start and you should be left with some thing like this

nvidia-settings --assign 'CurrentMetaMode'="DPY-3: 1920x1080_75 @1920x1080 +1962+0  {ViewPortIn=1920x1080, ViewPortOut=1920x1080+0+0}, DPY-0: 1920x1080_75 @1920x1080 +0+0 {ViewPortIn=1920x1080, ViewPortOut=1920x1080+0+0}, DPY-5: 1920x1080_75 @1920x1080 +3924+0 {ViewPortIn=1920x1080, ViewPortOut=1920x1080+0+0}"

So that command is run before playing a game where bezel correction is required. Run it again without the offsets to go back to normal.

Steam – Set launch option from command line

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Some games have various options when started from within Steam. For exmaple with F1 2019 you can choose dx12 or dx11.
This choice does not appear when you start the game from the command line in the form

steam steam://launch/928600

In the case of F1 2019 the dx12 exe will be started. which is no good on Linux. To set our choice to dx11 just append /option2 to the end of the command.

steam steam://launch/928600/option2

It does not work for the 

steam://rungameid/xxxxxx

form.

If you need to find which option number is the write one you can work it out within

~/.local/share/Steam/appcache/appinfo.vdf

(adjust if your Steam dir is elsewhere)
Not easy to read but try searching for the name of the executable you want to start and the correct option number should be close by. Or search for the games name.

compile gcc on odroid-u2 with mfpu=neon – Arch linux

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currently gcc 4.8.1 on Arch (07.10.13)

Flags in makepkg.conf

CPPFLAGS=""
CFLAGS="-O3 -pipe -march=armv7-a -mcpu=cortex-a9 -mfloat-abi=hard -mfpu=neon -fstack-protector --param=ssp-buffer-size=4"
CXXFLAGS="-O3 -pipe -march=armv7-a -mcpu=cortex-a9 -mfloat-abi=hard -mfpu=neon -fstack-protector --param=ssp-buffer-size=4"

PKGBUILD needs one patch adding (neon-update3.patch) and one removing (armhf-triplet-trunk.diff)
As it is patch will fail to find the file to be patched and you will have to supply the full path.
in my case

 /var/build/gcc/src/gcc-4.8-20130725/gcc/config/arm/neon.md

Also need to change flags pass to GCC by configure.

[[ $CARCH == "armv7h" ]] && CONFIGFLAG="--host=armv7l-unknown-linux-gnueabihf --build=armv7l-unknown-linux-gnueabihf --with-arch=armv7-a --with-float=hard --with-fpu=neon"

The PKGBUILD with the changes is attached as is neon-update3.patch

The original PKGBUILD is from https://github.com/archlinuxarm/PKGBUILDs/blob/master/core/gcc/PKGBUILD

neon-update3.patch is from http://gcc.1065356.n5.nabble.com/PATCH-ARM-Fix-unrecognizable-vector-comparisons-td947064.html

PKGBUILD.orig

PKGBUILD

neon-update3.patch

Force Mono (Black and White) with LPR

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In the below substitute HL4140CN with the printer name. (also the option names may difer, this is for a brother)

List the options with:

lpoptions -p HL4140CN -l

Add an “instance” of the printer with the option for Mono printing

lpoptions -p HL4140CN/bw -o BRMonoColor=Mono

Now the following will print Mono

lpr -P HL4140CN/bw any.txt

Disable Nvidia HDMI sound under Linux

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Sound under linux and KDE seems to able to get itself confused with its settings easily enough so their is no point adding to the confusion. I’m sure that HDMI is hugely useful to those that want it and use it but up to now I never have.
Among the issues I’ve noticed is that at seemingly random times the KDE mixer Kmix will revert to setting the Nvidia HDMI output as the master channel. Then I have to change it back which starts to get old fairly rapidly. Continue reading →