August 04, 2016


@signal_vs_noise on Twitter

I am an engineer at Google in Madison, WI, where I work on the Andromeda software defined network (NSDI 2018). Prior to this, I worked on the virtual machine monitor powering Google Compute Engine and as a committer on the DragonFly BSD project. My professional interests include operating systems and performance analysis & optimization.

This is my personal weblog. All writing here reflects my opinions alone, not those of my employer or any other affiliations.

In the summer of 2018 I will be attending Recurse Center, a self-directed & collaborative learning project in New York City. I will study discrete event simulation & queuing theory, following Lazowska's Quantitative System Performance and Harchol-Balter's Performance Modeling books. I will write blog posts with simulations & visualizations here - Recurse Center posts. If you're in or near New York City between July and October and want to cross paths, please reach out!

In the summer of 2012 I cycled from Baltimore, MD, to Portland, OR with the 4K for Cancer. The 4K was a unique experience in my life; I met amazing folks and saw such kindness across the country that I had never dreamed of. I recorded and photographed a small part of our journey and of 4K journeys after in an online journal, please take a look to follow along!

May 12, 2018 is a source code cross-reference I'm hosting for the Linux kernel and DPDK packet processing libraries. The cross-reference has both git history and tag information for indexed projects. It is running the opengrok indexer from Sun, originally for Solaris.

You can access annotation and revision tag information from the history tab of a particular source file, for example: linux/net/core/dev.c.

March 21, 2018

Organizations I'm supporting in 2018

Early in 2017, I committed to support a number of nonprofits and civil society organizations; I wrote about the organizations I planned to support and why: Organizations I'm supporting this year - broadly I planned to focus on civic and environmental groups. Last December, I looked back at the year and where I followed or deviated from plan: Organizations I've supported in 2017.

This year, I continue to support a broad set of nonprofits/organizations, primarily in civic and environmental sectors. New this year, I have added nuclear nonproliferation and science & society organizations (ex: Federation of American Scientists, Bulletin of Atomic Scientists) and the Center for Civilians in Conflict. Through the year, I plan to support the organizations below proportionally and to highlight specific work each/any does (such as policy papers/testimony/etc) that I think is important.


Union of Concerned Scientists15%
American Civil Liberties Union12%
Pro Publica8%Nonprofit newsroom; also serves as a resource for traditional news organizations
Environmental Defense Fund7%
Brennan Center for Justice5%
National Immigration Law Center4%
Natural Resource Defense Council4%
Northwest Immigrant Rights Project4%
Ploughshares Fund4%Grant-making nonprofit, focused on nuclear nonproliferation
University of Washington Climate Impacts Group, various4%
Rocky Mountain Institute4%Studies & writes on climate change, energy, and decarbonization
Center for Arms Control & Non-proliferation2%
Center for Democracy and Technology2%
Center for Civilians in Conflict2%
Federation of American Scientists2%Runs extraordinary Government Secrecy Project; provided recent comments on autonomous weapon systems
International Refugee Assistance Project2%
United to Protect Democracy2%
...17 others, <= 1%...

This does not include donations to candidates for office / PACs, raw data for those contributions are available on the FEC website. This does not include my carbon offset purchases at scale either.

I think public lists & commitments valuable to cast lights on work at civic nonprofits and to mobilize further support. If you know of any interesting civic, nonproliferation, or climate change nonprofits doing good work, I'd be interested to hear!

December 28, 2017

Organizations I've supported in 2017

"I have a little hope that America’s amazingly robust and wealthy civil society, which is unlike any other civil society in the world, ever, will change the situation, or will make it progress differently." - Masha Gessen, Apr 2017

Early in 2017, I committed to supporting a number of nonprofits; I wrote about the organizations I planned to support and why. I focused on civil society and on climate change organizations, with a bias towards legal groups. (I was inspired by DJ Capelis's post earlier).

2017 brought disruptions, natural triggers were amplified into logistic and human disasters. 2017 brought old fears into new focus - nuclear proliferation, civil-military relationship strains, use and control of force questions. Progress addressing climate change (emissions and decarbonization) has been disappointing. I found it difficult to sustain attention and focus on particular problems.

I did not foresee how 2017 would and did proceed.

The year also brought the incredible strength and depth of our civil society and their role in the public sphere into focus - legal organizations via lawsuits as expected, but policy and journalism organizations to educate and focus attention too. I did not know about whole classes of organizations in the policy and public education spaces just ten months ago, now I am deeply grateful for their works.

Breaking down my donations ---
By "area": image2.png
By organization: image1.png Top organizations:

Union of Concerned Scientists13.6%
Natural Resource Defense Council9.3%
Pro Publica5.6%
Electronic Frontier Foundation5.0%
Ploughshares Fund4.9%
American Civil Liberties Union4.9%
National Immigration Law Center4.5%
World Food Program3.6%
Global Zero3.0%
University of Washington Climate Impacts Group2.9%
Environmental Defense Fund2.75%
Northwest Immigrant Rights Project2.6%
International Medical Corps2.5%
Rocky Mountain Institute2.2%
International Rescue Committee1.9%
Freedom of the Press Foundation (Signal)1.6%
Team Rubicon1.3%
International Refugee Assistance Program1.25%
Brennan Center for Justice1.2%
Medicines Sans Frontieres0.9%
Mercy Corps0.9%
World Resources Institute0.9%
Let America Vote0.6%
Washington National Parks Fund0.6%

For the most part, I donated to the organizations I committed to. Standout differences --

  • I did not expect to have to think about weapons control and nonproliferation; and I did not know about the work of Ploughshares or Global Zero at the start of the year
  • I did not know about smaller "think-tank" environmental organizations, such as Rocky Mountain Institute (RMI), Resources for the Future, Ceres, etc. at the start of the year

I did not include donations to political candidates or organizations above.

I also began purchasing carbon offsets this year in bulk, as a direct means to mitigate unavoidable personal emissions and in excess of what zeroth-order calculators claim. I purchased 110 metric tons of offsets from the Bonneville Environmental Foundation, from cooleffects, from the Colorado Carbon Fund, and from a private provider. (Not included above). I am not sure about the effectiveness of carbon offsets to in bulk to mitigate climate change and would appreciate any data or arguments either way. Without additional arguments, I plan to purchase offsets for ~1000 metric tons through the end of 2018.

March 21, 2017

Detect. Transmit.

2017 is the 40th anniversary of the launch of the twin Voyager spacecraft. I found this essay about Voyager on the Internet years ago - I don't remember where and I can't find any breadcrumbs. I'm sharing it, lightly edited, as one of the finest space program essays I've ever found.

Voyager sketch
Voyager sketch by @TychoGirl

To imagine what being the Voyager probe would be like, consider the following:

Your life begins, conceived during the mid-60s golden years of the space program.

The core concepts of your design are settled during the first years of that decade, and refined for fifteen years as different attempts are made to extend the reach of man's knowledge first to the skies, then to our nearest neighbors.

Your idea forms in an era of slide-rules and pencils, as astronomical calculations reveal a particularly fortuitous alignment of the outer planets in the coming decade, one that will slingshot you to the outer reaches of the solar system, hopping from planet to planet.

Continue reading "Detect. Transmit."

February 12, 2017

Organizations I'm supporting this year

(updated 3/05)

I was inspired by DJ Capelis's post to discuss the nonprofits and funds I'm supporting this year and the reasons behind my choices.

A few themes -

  1. Nonprofits are an important part of society in that they bring together people who have been thinking about and working on specific problems for a long time.

    However - Nonprofits are not the answer to every problem and are not going to be able to right or even mitigate every harm. This is not the computer networking - there is no "routing around" damage here and now.

  2. A focus on legal organizations - Legal organizations (like the ACLU and EarthJustice) work through litigation, lobbying, and comment on rulemaking.

    Legal victories do not stand alone; at best they can buy space and time for public action and consensus to cement rulings or rules into the society.

  3. Allocation - Approximately half my donations are to civil organizations and half are to Environmental/Climate Change organizations

Civil Organizations
  • The American Civil Liberties Union - The ACLU is a traditional bulwark in defense of civil liberties. The organization is large and capable and there are legal fights only they can sustain.

    Of note - the ACLU is actually two organizations, a 501c4 (The American Civil Liberties Union) and a 501c3 (The American Civil Liberties Union Foundation). The 501c4 can spend on lobbying where the Foundation cannot, so I give to them.

  • Pro Publica is a news organization focused on investigative journalism and long-form stories. The series "Killing the Colorado" (river) was deeply interesting and supporting investigative journalism is important to me.
  • Brennan Center for Justice - a law-advocacy organization at NYU; has an ongoing project dedicated to Voting Rights and ballot access
  • Let America Vote - a new 501c4 organization focused on access to the ballot. I donated mainly because of the nature of the problem and the track record of its founders (Jason Kander).
  • National Immigration Law Center
  • Northwest Immigrant Rights Project
Environmental/Climate Change Organizations

I consider climate change to be a unique, grave threat. Environmental systems have complex dynamics and momentum - delayed intervention has been and will be much more expensive than earlier intervention and may be limited to mitigation. May 12, 2018
Organizations I'm supporting in 2018 March 21, 2018
Organizations I've supported in 2017 December 28, 2017
Detect. Transmit. March 21, 2017
Organizations I'm supporting this year February 12, 2017
4K for Cancer 2015 - Seattle, WA August 14, 2015
4K for Cancer Portland 2014 - Portland, OR August 16, 2014
A couple of days with 4K Portland 2014 July 31, 2014
4K for Cancer 2014 Sendoff & Day 1 June 08, 2014
Trust Fall June 06, 2014
4K for Cancer Seattle 2013 - Seattle, WA August 26, 2013
4K for Cancer Portland 2013 - Cannon Beach August 25, 2013
Baltimore to Portland September 29, 2012
Blink and life flies by. August 03, 2012
Day 68 -- Tillamook to August 02, 2012
Day 67 -- Corvallis to August 01, 2012
Halfway to Corvallis. After that, July 31, 2012
Before riding to Corvallis, Team July 31, 2012
Day 66 -- Eugene to July 31, 2012
Day 64 -- Rest day July 29, 2012
Crossing Country and Catching Up, part 1 July 18, 2012
In Denver, CO. Veiled mountain July 03, 2012
Something is hidden in the July 03, 2012
@4KPortland 200mi in 2 days, July 01, 2012
Welcome to Colorful Colorado! July 01, 2012
The country from Franklin, NE June 28, 2012
#4kportland Cheers from Arapahoe, NE!! June 28, 2012
#4kportland Day 33 -- To June 28, 2012
#4kportland Iowa is not flat!! June 23, 2012
#4kportland Day 28 -- Atlantic, June 23, 2012
#4kportland Day 25 -- Wheatland June 20, 2012
#4kportland Day 24 -- Iowa June 19, 2012
#4kportland Day 23 -- 120mile+ June 18, 2012
@4kportland Day 21 -- Chicago June 16, 2012
@4kportland winning June 09, 2012
#4kportland -- Cincinnati to Lexington, June 08, 2012
Intro & Twelve Days June 07, 2012
First week of #4kportland!! (@4KPortland) June 03, 2012
#4kportland Day 8 -- Canton, June 03, 2012
#4kportland at the host in June 02, 2012
#4kportland Day 7 -- Youngstown June 02, 2012
Reached host in Youngstown! _So_ June 01, 2012
#4kportland Day 6 -- Pittsburgh, June 01, 2012
#4kportland Day 4 -- Ligionier, May 30, 2012
4K day 2: Waking up May 28, 2012
@4KPortland group 4 is in May 27, 2012
My last night in Baltimore. May 27, 2012
An alumni's thoughts on 4K; May 18, 2012
IOCCC Korn 1987 August 04, 2007

May 2018
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December 2017
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August 2013
September 2012
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August 2007