Brendan Gregg
Computer performance engineer working on datacenter performance at OpenAI, previously Netflix and Sun/Joyent. Author of Systems Performance and BPF Performance Tools, and creator of flame graphs.
Brendan Gregg did not write this page. ppll compiled it from their own words, each linked to the source. Is this you? · Report a mistake
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What they believe
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AI datacenter growth makes performance engineering critical for saving the planet, not just cutting costs.
The staggering and fast-growing cost of AI datacenters is a call for performance engineering like no other in history; it's not just about saving costs - it's about saving the planet.
brendangregg.comSaid 6 Feb 2026This on korrents
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AI agents trained on an expert's published work can only automate a small fraction of that expert's actual job.
These would only automate about 15% of what I do as a performance engineer, and will go out of date if I'm not training it to follow industry changes.
brendangregg.comSaid 27 Nov 2025This on korrents
The bold line is korrents’ wording; the quote is theirs. These 2: what they wrote before what they said aloud, one per source, newest first.
Feed
As its own page →Hiding
13 March
7 February
6 February
From one piece Why I joined OpenAI 3 beliefs · brendangregg.com
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korrents.com
eBPF, Ftrace, and hardware performance counters are proven tools for finding datacenter performance wins.Their words
given those technologies are proven for finding datacenter performance wins, it seems likely
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Their words
I've realized that performance engineering as we know it may not be enough - I'm thinking of new engineering methods so that we can find bigger optimizations than we have before, and find them faster.
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korrents.com
AI datacenter growth makes performance engineering critical for saving the planet, not just cutting costs.Their words
The staggering and fast-growing cost of AI datacenters is a call for performance engineering like no other in history; it's not just about saving costs - it's about saving the planet.
5 December 2025
4 December 2025
27 November 2025
From one piece On "AI Brendans" or "Virtual Brendans" 3 beliefs · brendangregg.com
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korrents.com
Widespread AI-driven performance tuning agents will meaningfully reduce global energy waste.Their words
In future there will be AI performance agents that can be run on everything, helping to save the planet by reducing energy usage.
-
korrents.com
Relying on AI to replace performance engineers reduces an organization's overall technical expertise over time.Their words
If a company spends less on performance engineers as it's considered AI'd, it will reduce the company's effective "performance IQ."
-
korrents.com
AI agents trained on an expert's published work can only automate a small fraction of that expert's actual job.Their words
These would only automate about 15% of what I do as a performance engineer, and will go out of date if I'm not training it to follow industry changes.
21 November 2025
From one piece Intel is listening, don't waste your shot 2 beliefs · brendangregg.com
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Their words
It isn't easy dealing with peer pressure and a room of warm and friendly staff begging you say something, anything nice about their terrible product for fear of losing their jobs -- and realizing you must be brutal to their faces otherwise you're not helping the vendor or your own company.
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Their words
If you are in regular meetings with a hardware vendor as a customer (or potential customer) you can accomplish a lot by providing firm and tough feedback, particularly with Intel today.
16 November 2025
From one piece Third Stage Engineering 2 beliefs · brendangregg.com
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korrents.com
Fair hardware benchmarks must use the best software and tuning for each hardware option, not hardware specs alone.Their words
The most accurate and realistic evaluation for HW involves selecting the best software and then tuning it, and doing this for all HW options.
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korrents.com
Computer hardware performance depends on hardware, software, and tuning together, not hardware alone.Their words
You need all three stages to reach the highest, and most competitive, performance.
4 August 2025
3 August 2025
From one piece When to Hire a Computer Performance Engineering Team (2025) part 1 of 2 3 beliefs · brendangregg.com
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korrents.com
A performance test without an explanation of its limiting factor should be treated as unanalyzed and possibly bogus.Their words
Any performance test should be accompanied by an explanation of the limiting factor, since no explanation will reveal the test wasn't analyzed and the result may be bogus.
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korrents.com
Monitoring tools that do periodic work can themselves cause the latency outliers they were installed to diagnose.Their words
One performance anti-pattern is when a company, to debug one performance problem, installs a monitoring tool that periodically does work and causes application latency outliers.
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Their words
A new performance team can likely find enough optimizations to halve infrastructure spend in their first couple of years, even for companies that have been using commercial performance or observability tools.
14 July 2025
24 May 2025
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The Cuckoo's EggTheir words
The Cuckoo's Egg - Cliff Stoll (Gallery, 2005)
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CryptonomiconTheir words
Cryptonomicon - Neal Stephenson
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Applied CryptographyTheir words
Applied Cryptography - Bruce Schneier (Wiley, 1996)
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The Art of Unix ProgrammingTheir words
The Art of Unix Programming - Eric S. Raymond (Addison-Wesley, 2003)
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The Practice of ProgrammingTheir words
The Practice of Programming - Brian Kernighan, Rob Pike (Addison-Wesley, 1999)
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The Mythical Man-MonthTheir words
The Mythical Man-Month - Frederick P. Brooks (Addison-Wesley, 1995/1975)
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Expert C ProgrammingTheir words
Expert C Programming - Peter van der Linden (Prentice Hall, 1994)
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The C Programming Language, 2nd Ed.Their words
The C Programming Language 2nd Ed. - Brian W. Kernighan, Dennis M. Ritchie (Prentice Hall, 1988)
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The AWK Programming LanguageTheir words
The AWK Programming Language - Alfred V. Aho, Brian W. Kernighan, Peter J. Weinberger (Addison Wesley, 1988)
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UNIX: A History and a Memoir - Brian W Kernighan (independent, 2019)
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Just For Fun - Linus Torvalds (Harper, 2002)
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Where Wizards Stay Up Late - Katie Hafner, Matthew Lyon (Simon & Schuster, 1998)
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The No Asshole RuleTheir words
The No Asshole Rule - Robert I. Sutton (Business Plus, 2010)
22 May 2025
21 May 2025
From one piece 3 Years of Extremely Remote Work 2 beliefs · brendangregg.com
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korrents.com
Giving local staff authority over more-qualified remote workers reduces a company's competitivenessTheir words
there's a power imbalance: the local worker is in charge and doesn't have to listen. This reduces company competitiveness.
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korrents.com
Remote workers are often passed over for opportunities in favor of less-qualified local colleaguesTheir words
Opportunities can be given to local workers despite the remote worker being more qualified, or even number one in the world in that area.
30 April 2025
3 March 2025
2 March 2025
30 October 2024
28 October 2024
20 October 2024
16 August 2024
22 July 2024
21 July 2024
30 April 2024
24 March 2024
17 March 2024
10 March 2024
22 November 2023
21 September 2023
29 July 2023
16 April 2022
14 December 2021
6 October 2021
21 August 2021
15 August 2021
29 July 2020
5 April 2020
12 January 2020
22 December 2019
19 February 2019
Nothing matches.
Beliefs
Korrents What they believe 17 beliefs — each backed by an exact quote.
Each is a — compiled by korrents.com, not by them: the one-line wordings are korrents', the quotes are theirs.
Recent
AI datacenter growth makes performance engineering critical for saving the planet, not just cutting costs.
The staggering and fast-growing cost of AI datacenters is a call for performance engineering like no other in history; it's not just about saving costs - it's about saving the planet.
Why I joined OpenAI Said 6 Feb 2026
Traditional performance engineering methods are insufficient for the scale of modern AI datacenters and need new approaches.
I've realized that performance engineering as we know it may not be enough - I'm thinking of new engineering methods so that we can find bigger optimizations than we have before, and find them faster.
Why I joined OpenAI Said 6 Feb 2026
eBPF, Ftrace, and hardware performance counters are proven tools for finding datacenter performance wins.
given those technologies are proven for finding datacenter performance wins, it seems likely
Why I joined OpenAI Said 6 Feb 2026
Show 14 more
AI agents trained on an expert's published work can only automate a small fraction of that expert's actual job.
These would only automate about 15% of what I do as a performance engineer, and will go out of date if I'm not training it to follow industry changes.
On "AI Brendans" or "Virtual Brendans" Said 27 Nov 2025
Relying on AI to replace performance engineers reduces an organization's overall technical expertise over time.
If a company spends less on performance engineers as it's considered AI'd, it will reduce the company's effective "performance IQ."
On "AI Brendans" or "Virtual Brendans" Said 27 Nov 2025
Widespread AI-driven performance tuning agents will meaningfully reduce global energy waste.
In future there will be AI performance agents that can be run on everything, helping to save the planet by reducing energy usage.
On "AI Brendans" or "Virtual Brendans" Said 27 Nov 2025
Customers who give hardware vendors firm, tough feedback accomplish more with them
If you are in regular meetings with a hardware vendor as a customer (or potential customer) you can accomplish a lot by providing firm and tough feedback, particularly with Intel today.
Intel is listening, don't waste your shot Said 21 Nov 2025
Giving a vendor brutally honest feedback helps the vendor and the customer's own company more than polite praise given out of fear
It isn't easy dealing with peer pressure and a room of warm and friendly staff begging you say something, anything nice about their terrible product for fear of losing their jobs -- and realizing you must be brutal to their faces otherwise you're not helping the vendor or your own company.
Intel is listening, don't waste your shot Said 21 Nov 2025
Computer hardware performance depends on hardware, software, and tuning together, not hardware alone.
You need all three stages to reach the highest, and most competitive, performance.
Third Stage Engineering Said 16 Nov 2025
Fair hardware benchmarks must use the best software and tuning for each hardware option, not hardware specs alone.
The most accurate and realistic evaluation for HW involves selecting the best software and then tuning it, and doing this for all HW options.
Third Stage Engineering Said 16 Nov 2025
A new performance engineering team can typically halve a company's infrastructure spend within its first couple of years.
A new performance team can likely find enough optimizations to halve infrastructure spend in their first couple of years, even for companies that have been using commercial performance or observability tools.
When to Hire a Computer Performance Engineering Team (2025) part 1 of 2 Said 3 Aug 2025
Monitoring tools that do periodic work can themselves cause the latency outliers they were installed to diagnose.
One performance anti-pattern is when a company, to debug one performance problem, installs a monitoring tool that periodically does work and causes application latency outliers.
When to Hire a Computer Performance Engineering Team (2025) part 1 of 2 Said 3 Aug 2025
A performance test without an explanation of its limiting factor should be treated as unanalyzed and possibly bogus.
Any performance test should be accompanied by an explanation of the limiting factor, since no explanation will reveal the test wasn't analyzed and the result may be bogus.
When to Hire a Computer Performance Engineering Team (2025) part 1 of 2 Said 3 Aug 2025
Remote workers are often passed over for opportunities in favor of less-qualified local colleagues
Opportunities can be given to local workers despite the remote worker being more qualified, or even number one in the world in that area.
3 Years of Extremely Remote Work Said 21 May 2025
Giving local staff authority over more-qualified remote workers reduces a company's competitiveness
there's a power imbalance: the local worker is in charge and doesn't have to listen. This reduces company competitiveness.
3 Years of Extremely Remote Work Said 21 May 2025
NVIDIA's Nsight Graphics GPU flame graphs are shallow and cumbersome to use compared to full-stack profiling tools
They do have flame graphs in Nsight Graphics for GPU workloads, although their flame graphs are currently shallow as it is GPU code only, and onerous to use as I believe it requires an interposer; on the plus side they have click-to-source.
Doom GPU Flame Graphs Said 30 Apr 2025
Major Linux distributions are increasingly shipping system libraries with frame pointers enabled by default
This is getting easier in the lastest versions of Fedora and Ubuntu (e.g., Ubuntu 24.04 LTS) which are shipping system libraries with frame pointers by default.
Doom GPU Flame Graphs Said 30 Apr 2025
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Recommends rcmnd
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Compiled by rcmnd.app, not by them: the quotes are theirs, and each links to the post it was copied from.
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brendangregg.com 24 May 2025
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Recommends The C Programming Language, 2nd Ed.
The C Programming Language 2nd Ed. - Brian W. Kernighan, Dennis M. Ritchie (Prentice Hall, 1988)
brendangregg.com 24 May 2025
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Recommends Expert C Programming
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Recommends The Mythical Man-Month
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Recommends The Design of the Unix Operating System
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What others say about The Design of the Unix Operating System →
Recommends Understanding the Linux Kernel, 3rd Ed.
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brendangregg.com 24 May 2025
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What others say about Understanding the Linux Kernel, 3rd Ed. →
Recommends Linux Kernel Development, 3rd Ed.
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Recommends The Practical Performance Analyst
The Practical Performance Analyst - Neil Gunther (McGraw Hill, 1997)
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Recommends The Art of Capacity Planning
The Art of Capacity Planning - John Allspaw (O'Reilly, 2008)
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Recommends BPF Performance Tools
Recommends Systems Performance, 2nd edition
Systems Performance 2nd edition - Brendan Gregg (Addison-Wesley, 2021)
brendangregg.com 24 May 2025
their own
Where they publish
Site brendangregg.com His personal site: performance methodologies, eBPF/BPF tools, flame graphs and his book list.
Link verified 4 Sept 2026.
Blog Brendan Gregg's Blog His personal blog, separate from the reference pages on the same site.
Recent
- Why I joined OpenAI 6 Feb 2026 The staggering and fast-growing cost of AI datacenters is a call for performance engineering like no other in history; it's not just about saving costs – it's about saving the planet. I have joined OpenAI to work…
- Leaving Intel 4 Dec 2025 InnovatiON 2022 AI Flame Graphs GPU Flame Scope Harshad Sane SREcon APAC Cloud strategy Last day I've resigned from Intel and accepted a new opportunity. If you are an Intel employee, you might have seen my fairly long…
- On "AI Brendans" or "Virtual Brendans" 27 Nov 2025 There are now multiple AI performance engineering agents that use or are trained on my work. Some are helper agents that interpret flame graphs or eBPF metrics, sometimes privately called AI Brendan; others have trained…
Show 7 more
- Intel is listening, don't waste your shot 21 Nov 2025 Intel's new CEO, Lip-Bu Tan, has made listening to customers a top priority, saying at Intel Vision earlier this year: "Please be brutally honest with us. This is what I expect of you this week, and I believe harsh feed…
- Third Stage Engineering 16 Nov 2025 The real performance of any computer hardware in production is the result of the hardware, software, and tuning; the investment and sequence of these efforts can be pictured as a three-stage rocket: I recently presented…
- When to Hire a Computer Performance Engineering Team (2025) part 1 of 2 3 Aug 2025 As a leader in computer performance I've been asked by companies about how (and why) to form a performance engineering team, and as this is broadly useful I'll share my advice here. Large tech companies in the US hire p…
- 3 Years of Extremely Remote Work 21 May 2025 In the last 3 years I've attended 77 meetings that began between 1am and 6am, roughly once every two weeks, followed by my usual 7am start, Monday to Saturday. I'm working remotely from Australia for a US firm (Intel) w…
- Doom GPU Flame Graphs 30 Apr 2025 AI Flame Graphs are now open source and include Intel Battlemage GPU support, which means it can also generate full-stack GPU flame graphs for providing new insights into gaming performance, especially when coupled with…
- AI Flame Graphs 28 Oct 2024 Imagine halving the resource costs of AI and what that could mean for the planet and the industry -- based on extreme estimates such savings could reduce the total US power usage by over 10% by 20301. At Intel we've bee…
- No More Blue Fridays 21 Jul 2024 In the future, computers will not crash due to bad software updates, even those updates that involve kernel code. In the future, these updates will push eBPF code. Friday July 19th provided an unprecedented example of t…
Link verified 4 Sept 2026. Recent items update automatically from the channel.
x.com @brendangregg Posts about systems performance and eBPF.
Recent
- Huge news for Doctor Who fans: DMP 1 & 3 found! 13 Mar 2026 bbc.com
- New blog post: Why I joined OpenAI 7 Feb 2026 brendangregg.com
- New post: Leaving Intel 5 Dec 2025 brendangregg.com
Show 16 more
- new post: When to Hire a Computer Performance Engineering Team (2025) part 1 of 2 4 Aug 2025
- Had a great time at #srenext Tokyo 14 Jul 2025
- new blog post: 3 Years of Extremely Remote Work 22 May 2025
- New blog post: Doom GPU Flame Graphs, a fun demo of AI/GPU Flame Graphs and FlameScope, now open source 30 Apr 2025
- My website is back online https://t.co/1cRpD64hyP after migrating to a different provider (and https works again) 3 Mar 2025
- My website is online as http at https://t.co/1cRpD64hyP, but I just broke the https links, sorry. If you delete the "s" then the links should still work. 2 Mar 2025
- AI Flame Graphs: Showing what's actually running on the HW and how we got there. Uses Intel EU stall profiling and eBPF. 30 Oct 2024
- WSJ covering the eBPF "super revolutionary technology" 16 Aug 2024 wsj.com
- New post: No More Blue Fridays: How eBPF is already being adopted to prevent kernel crashes 22 Jul 2024 brendangregg.com
- New blog post: Linux crisis tools 24 Mar 2024 brendangregg.com
- New blog post: The Return of the Frame Pointers (Fedora, Ubuntu) 17 Mar 2024
- New blog post: eBPF Documentary 10 Mar 2024 brendangregg.com
- USENIX @SREcon APAC is only 5 weeks away! See you in Singapore 9 May 2023 usenix.net
- new post: eBPF Observability Tools are not Security Tools 28 Apr 2023 brendangregg.com
- Slides and video from my SREcon22 APAC keynote on computing performance futures https://t.co/slq6CP2Ygy #SREcon @usenix 1 Mar 2023
- USENIX @SREcon APAC CFP is due in two weeks (March 2nd): 17 Feb 2023 brendangregg.com
Link verified 4 Sept 2026. Recent items update automatically from the channel.
Mastodon @brendangregg@aus.social His Mastodon account on aus.social.
Link verified 4 Sept 2026.
GitHub github.com/brendangregg FlameGraph, perf-tools, bpf-perf-tools-book and other performance tooling.
Recent
- FlameGraph — Stack trace visualizer 20 Oct 2024
- bpf-perf-tools-book — Official repository for the BPF Performance Tools book 30 Apr 2024
- perf-tools — Performance analysis tools based on Linux perf_events (aka perf) and ftrace 22 Nov 2023
Show 13 more
- GuessingGame — Guessing game written in many programming languages 21 Sept 2023
- BPF-tools — Performance Tools using Linux eBPF 29 Jul 2023
- FlameScope — coming soon 16 Apr 2022
- pmc-cloud-tools — PMC (Performance Monitoring Counter) tools for the cloud 14 Dec 2021
- HeatMap — Heat map generation tools 6 Oct 2021
- Chaosreader — An any-snarf program that processes application protocols (HTTP/FTP/...) from tcpdump or snoop files and stores session and file data 21 Aug 2021
- wss — Working Set Size tools 15 Aug 2021
- msr-cloud-tools — MSR Cloud Tools 29 Jul 2020
- bpf-perf-workshop 5 Apr 2020
- systemtap-lwtools — SystemTap Lightweight Tools 12 Jan 2020
- bpf-typewriter — BPF noisy typewriter (bpftrace) 22 Dec 2019
- Misc — Misc 19 Feb 2019
- wrmsrbench — WRMSR micro benchmark 19 Feb 2019
Link verified 4 Sept 2026. Recent items update automatically from the channel.
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Some people here publish in a language other than English. Where they do, this site shows a machine translation beneath the post, in this typeface — the site's own, not theirs.
The post itself is never changed, moved or hidden: what is set in the serif above is exactly what the person published, and it is what to quote them on. A translation can be wrong in ways that matter, especially about tone.
Only the post's own words are translated. A quoted post, a linked article and a belief on korrents.com are left in their original language.