October 2019 - Talk - lists.gtalug.org

rr: debugging using replays
by D. Hugh Redelmeier 10 Oct '19

10 Oct '19

[I previously sent this to the libreswan developers list.] I don't use gdb much. Consequently I'm clumsy using it. Consequently I don't use gdb much. This tool looks like it might make gdb a lot more useful: <https://rr-project.org/> It is a Mozilla research project. But at this point it just works. Have a look at the videos on that page. Idea: (with limitation) you run a program under rr to record that run. When it is captured, you can replay it (forward and back!) as many times as you want, from within GDB. Breakpoints and all work. It supports multithreaded programs, but it only allows one core to be used. (I have no idea whether it supports fork.) For a non-deterministic bug, you keep rerunning the recording step until you observe the problem. You can replay that execution as much as you want without the non-determinism shifting on you. Some kinds of output are lost: in demos of debugging Firefox, Firefox windows were not created during replay. But anything that the program actually examines comes from the recording. The overhead comes in two parts: - run time during recording. That seems fine: less than a factor of two. - RAM requirements. That can get large. It mostly records everything that passes into and out of each system call. If they can debug Firefox with this, I imagine that we could debug even large programs.

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LibrePlanet Canada 2020 (Satellite Edition)
by Stephen Paul Weber 09 Oct '19

09 Oct '19

Hello LUGers! Next year, in 2020, I will be facilitating bringing LibrePlanet as a "satellite edition" to Ontario! LibrePlanet is an annual conference about software freedom, user rights, philosophy and technology. Main talks will still be in Boston, being streamed in to a local venue along with local hallway track, swag, etc. For more information see <https://2020.libreplanet.ca/> or contact me directly if you're interested in helping. Additionally if your employer, or some other place you have contact with might be interested in sponsoring, I'd be happy to hear about that as we're still actively seeking sponsors (the event will go forward without them, but we can make it so much more awesome with them!)

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"Discovering Hard Disk Physical Geometry through Microbenchmarking"
by D. Hugh Redelmeier 08 Oct '19

08 Oct '19

This goes quite deeply into HDD geometry. Probably a waste of time for most people, but I found it facinating. <http://blog.stuffedcow.net/2019/09/hard-disk-geometry-microbenchmarking/>

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X270 for $559
by William Park 08 Oct '19

08 Oct '19

FYI, https://www.lenovo.com/ca/en/laptops/thinkpad/thinkpad-x/ThinkPad-X270/p/20… I bought similar spec'ed refurbished T450 for $315, but this one is new. -- William Park <opengeometry(a)yahoo.ca>

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[GTALUG-Announce] Meeting on Tuesday, October 08 at 07:30 PM
by hi＠gtalug.org 07 Oct '19

07 Oct '19

<https://gtalug.org/meeting/2019-10/> # The state of Mozilla with Mike Hoye and AGM Mike Hoye will be joining us to talk where Firefox, Mozilla and the Web are today, and where they're going. The second part of the meeting will be GTALUG's Annual general meeting. * Members run and vote for directors of the board. * Annual financial report. ## Location George Vari Engineering and Computing Centre 245 Church Street, Room 203 Ryerson University <https://goo.gl/maps/16oJ2> <https://www.openstreetmap.org/way/23447525> ## Schedule * 6:00 pm - Please discuss on the general mailing list (i.e. <talk(a)gtalug.org>) where you want to go for dinner. * 7:30 pm - Meeting and presentation. * 9:00 pm - After each meeting, a group of GTALUGers move to The Imperial Pub (54 Dundas St East) for refreshments and more socialising. # Code of Conduct We want a productive happy community that can welcome new ideas, improve every process every year, and foster collaboration between individuals with differing needs, interests and skills. We gain strength from diversity, and actively seek participation from those who enhance it. This code of conduct exists to ensure that diverse groups collaborate to mutual advantage and enjoyment. We will challenge prejudice that could jeopardise the participation of any person in the community. The Code of Conduct governs how we behave in public or in private whenever the Linux community will be judged by our actions. We expect it to be honoured by everyone who represents the community officially or informally, claims affiliation or participates directly. It applies to activities online or offline. We invite anybody to participate. Our community is open. Please read more about the GTALUG Code of Conduct here: <https://gtalug.org/about/code-of-conduct/>. If you have any questions, comments, or concerns about the GTALUG Code of Conduct please contact the GTALUG Board @ <board(a)gtalug.org>. --- GTALUG Announce mailing list announce(a)gtalug.org https://gtalug.org/mailman/listinfo/announce

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getting Firefox to exploit GPU
by D. Hugh Redelmeier 04 Oct '19

04 Oct '19

By default, on Linux, Firefox does not use the GPU for rendering web pages. You can enable this by a setting in about:config gfx.webrender.all Change that from false to true I don't actually know that much about the performance impact. Apparently Mozilla leaves this off just to minimize support problems. It isn't that the Firefox code is buggy. There have been times where there were problems with some components the Linux graphics stack. I'm trying this with my notebook now. Why? I learned about this by asking a Mozilla guy before a meeting and it was easier and quicker to change my browser setting than it was to write a note. I'd love to hear any experience with this setting.

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Economist article on open source
by Evan Leibovitch 04 Oct '19

04 Oct '19

Hi all. Here's a nicely-done (and very positive) article on the global influence of open source and the emergence of open hardware: https://www.economist.com/leaders/2019/10/05/the-rise-of-open-source-comput… -- Evan Leibovitch, Toronto Canada @evanleibovitch or @el56

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Running Dell branded Nvidia gtx 1060 in non-dell system
by Alex Volkov 03 Oct '19

03 Oct '19

Hey everyone, I'm looking to buy used Nvidia GeForce GXT 1060 to run some ML tutorials. I got a good deal on Dell OEM one. Are there any pitfalls in running one in a non-dell system? More specifically nothing even close to that i.e amd fx CPU and AMD 970 chipset. Alex. -- Sent from my Android device with K-9 Mail. Please excuse my brevity.

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[GTALUG-Announce] Meeting on Tuesday, October 08 at 07:30 PM
by hi＠gtalug.org 02 Oct '19

02 Oct '19

<https://gtalug.org/meeting/2019-10/> # The state of Mozilla with Mike Hoye and AGM Mike Hoye will be joining us to talk where Firefox, Mozilla and the Web are today, and where they're going. The second part of the meeting will be GTALUG's Annual general meeting. * Members run and vote for directors of the board. * Annual financial report. ## Location George Vari Engineering and Computing Centre 245 Church Street, Room 203 Ryerson University <https://goo.gl/maps/16oJ2> <https://www.openstreetmap.org/way/23447525> ## Schedule * 6:00 pm - Please discuss on the general mailing list (i.e. <talk(a)gtalug.org>) where you want to go for dinner. * 7:30 pm - Meeting and presentation. * 9:00 pm - After each meeting, a group of GTALUGers move to The Imperial Pub (54 Dundas St East) for refreshments and more socialising. # Code of Conduct We want a productive happy community that can welcome new ideas, improve every process every year, and foster collaboration between individuals with differing needs, interests and skills. We gain strength from diversity, and actively seek participation from those who enhance it. This code of conduct exists to ensure that diverse groups collaborate to mutual advantage and enjoyment. We will challenge prejudice that could jeopardise the participation of any person in the community. The Code of Conduct governs how we behave in public or in private whenever the Linux community will be judged by our actions. We expect it to be honoured by everyone who represents the community officially or informally, claims affiliation or participates directly. It applies to activities online or offline. We invite anybody to participate. Our community is open. Please read more about the GTALUG Code of Conduct here: <https://gtalug.org/about/code-of-conduct/>. If you have any questions, comments, or concerns about the GTALUG Code of Conduct please contact the GTALUG Board @ <board(a)gtalug.org>. --- GTALUG Announce mailing list announce(a)gtalug.org https://gtalug.org/mailman/listinfo/announce

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some USB sticks are slow!
by D. Hugh Redelmeier 02 Oct '19

02 Oct '19

I bought some inexpensive SanDisk Cruzer Glide 16GB USB sticks from Walmart last year. Cheap. Today I copied the CentOS 8 installation image onto one. time sudo dd if=CentOS-8-x86_64-1905-dvd1.iso of=/dev/sdg oflag=direct bs=16M (I used a USB 3 port on my dessktop.) It seemed to take a long time, so I did this to see if anything was happening (the dd process' PID was 29047): sudo kill -s USER1 29047 Yes, there was progress, but not as much as I would expect. The final statistics were: 425+1 records in 425+1 records out 7135559680 bytes (7.1 GB, 6.6 GiB) copied, 1560.63 s, 4.6 MB/s real 26m4.152s user 0m0.072s sys 0m4.706s This amounts to about 4.56 MB/s. That's even less than the poor Average Sustained Write Speed 7.64 MB/s reported here: <https://usb.userbenchmark.com/SpeedTest/2718/SanDisk-Cruzer-Glide> Note: this stick hasn't been written to often. It should not be near the end of its life (that could slow down a flash device).

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