brendangregg

5 ms·

1.
by brendangregg 7mo ago
I'm hoping for more Troughton too some day. And speaking of Jamie: https://www.brendangregg.com/blog/images/2025/brendan_hines....
2.
by brendangregg 8mo ago
Thanks, I never saw the Tech Crunch parodies before. I also didn't use the words "make/making the world a better place". I actually said "it's about saving the planet" based on all the environmentally worr
3.
by brendangregg 8mo ago
Given the widely reported issue of AI environmental cost, and being among the top people in the world who can fix it, I don't feel comfortable with _inaction_. I can reduce datacenter sizes, so I'll do that. As a performance engin
4.
by brendangregg 8mo ago
No, that's not what they say.
5.
by brendangregg 8mo ago
When did I say I don't think comp is important?
6.
by brendangregg 8mo ago
As an engineer I can't comment on future company predictions. It sounds like a question for Sam Altman, as he has discussed risks in the past. My wife was paying for ChatGPT before I joined. I didn't ask Mia. I probably have three
7.
by brendangregg 8mo ago
Again, many comments here saying I only care about the money, and while comp is an important factor I think it characterizes me as someone I'm not, and forgets what I've been doing for the past two decades. I've spent thousan
8.
by brendangregg 8mo ago
To answer a few people at once: I did mention compensation as a factor in the post, but I didn't elaborate details, so easy to miss. Comp is important of course, but so are the other factors. It feels like I can't go for a day wit
9.
by brendangregg 9mo ago
Funny to see this fixed in 2023 and the side effects. Back in 2004, before I focused on performance, I did some security work including inter-keystroke latency analysis of captured SSH sessions to estimate the commands typed: https:/&
10.
by brendangregg 10mo ago
Yeah, different numbers, 110 customer meetings, the other post tracked 1-6am meetings. I'm glad I tracked 1-6am meetings since I've shared that number when people think that remote workers aren't making an effort.
11.
by brendangregg 10mo ago
Right, laser 300 was called the VZ300 here. I'm out of desk space so I had to put the VZ300 on a stand above my C64C. Maybe AI can finally help me code some C64 and VZ games. :-)
12.
by brendangregg 10mo ago
I like to measure things. In real life and on computers. But I also have a couple of work reasons for it: As a remote worker, I'm under extra pressure to prove that remoteness works. As a senior employee, I'm also under pressure t
13.
by brendangregg 1y ago
I actually only just got the C64C and was surprised I could get it to fit on my desk. C64Cs are massive. Now to connect it to some display...
14.
by brendangregg 1y ago
Right, this kind of job can improve, and should improve. But right now there's talk of ending remote work entirely, without considering that people have been making the effort for years, hence sharing an anecdote. The bigger point is t
15.
by brendangregg 1y ago
Thanks, glad it's useful!
16.
by brendangregg 1y ago
To everyone building these things: Please add a disclaimer to say something like: "This is not a vulnerability: eBPF currently requires root access to do this. Also, eBPF makes this easy but does not make it possible, as debuggers, int
17.
by brendangregg 1y ago
I could just regenerate these heat maps with 60 rows instead of 50. I'm limited by the sampling rate that was captured in the profile data file. To provide even more resolution (so you had many samples within a game frame) I'd nee
18.
by brendangregg 1y ago
The origin problem for flame graphs was MySQL server performance involving dozens of threads: as a timeline view you need dozens of timelines, one for each thread, since if you render it on one (I know this is probably obvious) then you hav
19.
by brendangregg 1y ago
Nice tool. Looks like it uses what we now call a "flame chart" (not a flame graph). I don't know if it ever had an original name, but I've seen these in tools from at least the 1990's.
20.
by brendangregg 1y ago
The answer has always been in the source of flamegraph.pl: # This was inspired by Neelakanth Nadgir's excellent function_call_graph.rb # program, which visualized function entry and return trace events. As Neel # wrote: "
21.
by brendangregg 2y ago
Microsoft have been driving the work to make eBPF an IETF industry standard.
22.
by brendangregg 2y ago
Yes, we know eBPF must attach to equivalent events to Linux, but given there are already many event sources and consumers in Windows, the work is to make eBPF another consumer -- not to invent instrumentation frameworks from scratch. Just t
23.
by brendangregg 2y ago
Right, and we wanted to talk about all security solutions and not make this about one company. We also wanted to avoid shaming since they have been seriously working on eBPF adoption, so in that regard they are at the forefront of doing the
24.
by brendangregg 2y ago
Right; disabling eBPF doesn't solve this. And the bigger point is that this kind of eBPF is still super-user only. Apart from the more exotic facilities, the critical facilities that would be hard to disable include LD_PRELOAD for inte
25.
by brendangregg 3y ago
My preference is tools that give a rolling output as it let you capture the time-based pattern and share it with others, including in JIRA tickets and SRE chatrooms, whereas top's generally clear the screen. atop by default also sets u
26.
by brendangregg 3y ago
strace is ok as a last resort, but "perf trace" and bpf tracing tools are the production-safe alternative. https://www.brendangregg.com/blog/2014-05-11/strace-wow-much...
27.
by brendangregg 3y ago
It's not ridiculous at all. Who are you? You are backing away from your other positions, for example: > I fail to understand the reasoning of it "being simple" or "microbenchmarkey". It's far from the truth
28.
by brendangregg 3y ago
I didn't pull this argument out of nowhere, please read the direct comment I was replying to. Your position is also completely untenable: this benchmark was obsoleted by its creators 29 years ago, who very clearly say it is obsolete, a
29.
by brendangregg 3y ago
I think you missed the context of what I was responding to, which was about whether databases could even have micro-benchmarks. You also missed the word "Obsolete" splattered all over the website you sent me, and the text that TPC
30.
by brendangregg 3y ago
For a busy 64-CPU production JVM, I tested Google's Java symbol logging agent that just logged timestamp, symbol, address, size. The c2 compiler was so busy, constantly, that the overhead of this was too high to be practical (beyond st

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