Top all-time · #66
Brendan Gregg
Personal blog · brendangregg.com · on HN as brendangreggsystemsprogramming
Brendan Gregg's personal blog at brendangregg.com covers systems and programming. Since 2010, 450 different Hacker News readers have linked it 698 times, most often “Linux Performance”. It is still writing: the last post was on 2026-02-06, and you can follow it by feed.
Sometimes recommended · 13 of 40 sampled comments recommend it?
Why HN links it
HN readers link Brendan Gregg's blog and site for Linux and BPF performance tools, flame graphs and the USE method, usually to cite specific techniques or recommend his talks and book.
- Recommended for · 13 comments
- Called "excellent", "good" and "useful"; talks and book recommended; "totally worth your time".
Summarised by Claude from a sample of 40 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Brendan Gregg's homepage: I use this site to share various things, mostly my work with computers, specifically, computer performance analysis and methodology.
Most-linked posts?
- Linux Performance22 people · 24 mentions · first linked 2014-02-25
- Flame Graphs17 people · 17 mentions · first linked 2022-05-12
- /12 people · 12 mentions · first linked 2015-06-30
- Flame Graphs (2014)12 people · 12 mentions · first linked 2015-08-20
- Linux Performance Observability Tools11 people · 11 mentions · first linked 2021-09-27
- Linux Load Averages: Solving the Mystery9 people · 9 mentions · first linked 2017-08-08
- BPF Performance Tools Book8 people · 10 mentions · first linked 2019-09-27
- AWS EC2 Virtualization 2017: Including Nitro8 people · 9 mentions · first linked 2017-11-30
- Perf Examples8 people · 9 mentions · first linked 2014-04-13
- Linux EBPF Tracing Tools8 people · 8 mentions · first linked 2017-02-20
What Hacker News says?
It definitely (obviously?) wasn't me. I had introduced Brendan to DTrace in 2004 (over e-mail) when I discovered his earlier psio work[0] (which was based on TNF, a tracing facility that predated DTrace that was better than nothing -- but not by much). I knew that he was going to be very excited to learn about DTrace, and it wasn't long before he was delighting us with some really creative scripts. (His shellsnoop.d…
Comment linking /DTrace/shellsnoop.d
on “An Unbelievable Demo”Submitted An Unbelievable Demo as a story · 2339 points
HN discussionServerless doesn't make sense for every workload, and it may not be a good fit here, but there's a few issues with this article and the setups discussed on both the serverless and regular setups. I'll start with the initial setup: We can see m1 and t1 instances in there, as well as an m3. These first two are almost certainly running paravirtualized AMIs, and there is a chance the m3 is as well. PV AMIs are going to…
Comment linking /blog/2017-11-29/aws-ec2-virtualization-2017.html
on “Serverless: slower and more expensive”Submitted The return of the frame pointers as a story · 684 points
HN discussionBPF link: http://www.brendangregg.com/blog/2019-12-02/bpf-a-new-type-o...
Comment linking /blog/2019-12-02/bpf-a-new-type-of-software.html
on “The Lesson to Unlearn”Submitted CPU Utilization is Wrong as a story · 624 points
HN discussion"eBPF is the New Linux" http://www.brendangregg.com/bpf-performance-tools-book.html
Comment linking /bpf-performance-tools-book.html
on “Ask HN: What Skills to Acquire in 2020?”Submitted Linux Load Averages: Solving the Mystery as a story · 623 points
HN discussionIn this case you'd want to discover a network bottleneck by looking at network utilization directly using a command like `sar n DEV 1`. (from http://www.brendangregg.com/Articles/Netflix_Linux_Perf_Anal... ) It's generally possible to go 3x-10x faster than Linux if you make some tradeoffs like dedicating cores to polling. See https://www.usenix.org/node/186147 and https://wiki.fd.io/view/VPP/What_is_VPP%3F Moore's…
Comment linking /Articles/Netflix_Linux_Perf_Analysis_60s.pdf
on “Making the Tokio scheduler 10x faster”Submitted BPF: A New Type of Software as a story · 603 points
HN discussiontl;dr: * Netflix had a bug in their code. * But Express.js should throw an error when multiple route handlers are given identical paths. * Also, Express.js should use a different data structure to store route handlers. EDIT: HN commentors disagree. * node.js CPU Flame Graphs ( http://www.brendangregg.com/blog/2014-09-17/node-flame-graph... ) are awesome!
Comment linking /blog/2014-09-17/node-flame-graphs-on-linux.html
on “Node.js in Flame Graphs”Submitted Linux Crisis Tools as a story · 596 points
HN discussionFor Linux, look at the eBPF tools - they're really useful[0]. I've used them to troubleshoot annoying problems before, and they're far more practical to use than the usual `strace -f ./program` dance. Troubleshooting system issues can also be done with SystemTap[1], which looks cool, but I haven't personally tried it yet. [0]: A cool example of using them is https://www.brendangregg.com/blog/2021-08-27/slack-crashes…
Comment linking /blog/2021-08-27/slack-crashes-secret-stderr.html
on “New(ish) command line tools”Submitted Linux Performance as a story · 536 points
HN discussionBrendan Gregg's talks on Linux performance. Scroll down to "Talks": http://www.brendangregg.com/linuxperf.html
Comment linking /linuxperf.html
on “Ask HN: What are some of the best technical talks you've heard?”Submitted DTrace for Linux 2016 as a story · 482 points
HN discussion> The people actually doing the work don’t have time to talk about it and the people spending all their time talking about it aren’t doing the work. I think that's a really sad and cynical view. I assume you don't spend 16 hours a day writing code. I assume you have hobbies and other interests. For some people, educating others about their favorite topics is their hobby. Writing about their projects is their hobby.…
Comment linking /
on “Most tech content is bullshit”Submitted No More Blue Fridays as a story · 481 points
HN discussionYes. It's the default output for "perf report". I recommend reading this: https://www.brendangregg.com/perf.html However, the short 2-line way to get that output is the following: perf record -F99 -g --pid $(pidof consul) # Wait a few seconds and hit ctrl-c perf report You'll get similar output to what they show if you have consul running with a similar load :)
Comment linking /perf.html
on “Roblox October Outage Postmortem”Submitted Solaris to Linux Migration 2017 as a story · 440 points
HN discussionNB: Post author here. We've been meaning to add IQR as an accessor function for these, may have to go back and do it...the frequency trails [1] stuff from Brendan Gregg also goes into some of this and it's really cool as a visualization. [1]: https://www.brendangregg.com/FrequencyTrails/mean.html
Comment linking /FrequencyTrails/mean.html
on “How percentile approximation works and why it's more useful than averages”Submitted Brendan at Intel.com as a story · 397 points
HN discussionAWS re:Invent 2019: BPF performance analysis at Netflix (OPN303-R1) Youtube video: https://www.youtube.com/watch?v=16slh29iN1g Blog post: http://www.brendangregg.com/blog/2019-12-22/bpf-theremin.htm... Why? Brendan presents news tools and new flows that can be used to analyse performance bottlenecks. He get you in the demo and you stay to receive more and more information. It seems to be a talk that he has been impr…
Comment linking /blog/2019-12-22/bpf-theremin.html
on “Ask HN: Best Talks of 2019?”Submitted Leaving Intel as a story · 338 points
HN discussionHe's got some creds: http://www.brendangregg.com/
Comment linking /
on “Writing a book: is it worth it?”Submitted Working at Netflix as a story · 337 points
HN discussionbrendangregg is clearly trying to educate people who may not be aware of the difference between "CPU is busy" and "CPU is doing useful work." You already know this, and that's okay! You're not the target audience. I concede his title was slightly on the side of "I'm going to say something simple and catchy, then walk it back a bit with a nuanced explanation", but I'm willing to give him slack considering his numerou…
Comment linking /portfolio.html
on “CPU Utilization is Wrong”Submitted ZFS is mysteriously eating my CPU as a story · 332 points
HN discussionBy clicking through some links on the article I found this: http://www.brendangregg.com/blog/2014-10-31/cpi-flame-graphs... Now I wonder how easy and manual work it would be to do these combined flamegraphs with CPI/IPC information? My cursory search didn't find nary a mention after 2015... Perhaps this is still hard and complicated. To me it seems really useful to know why a function takes so long to work (waiting…
Comment linking /blog/2014-10-31/cpi-flame-graphs.html
on “CPU Utilization is Wrong”Submitted Why Don't You Use as a story · 326 points
HN discussion
