4 ms·

Linux perf rides the rocket

101 points by akerl_ 12y ago

kosinus 12y ago
Relevant Ubuntu bug: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1317811 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1317811 Relevant upstream discussion: http://www.spinics.net/lists/netdev/msg282340.html http://www.spinics.net/lists/netdev/msg282340.html
kazinator 12y ago
> This is pretty amazing. perf shows line numbers of those that can be instrumented directly, and those that can't in blue. That looks like it just came from debugging info. I.e. the numbered lines correspond to places where a debugger could put a breakpoint.
pyvpx 12y ago
is anyone aware of similar articles for any of the BSD flavors or other operating systems?
- wmf 12y ago
  Brendan Gregg has written many articles and a few books about DTrace which is included in FreeBSD.
- brendangregg 12y ago
  Depends how similar. This article was specifically about kernel line number and local variable tracing, which I've only seen Linux do. If you mean general kernel debugging, then my book on DTrace covers multiple operating systems including FreeBSD, and has around a thousand pages of examples. It would be nice if DTrace could add kernel line number and local variable tracing. Recently I've seen FreeBSD kernel builds where inlining has become more common than I've seen in the past, and missing kernel functions is becoming a bit of a nuisance. It's generally possible to work around it, but it would be nice to just trace lines and variables if needed.
derefr 12y ago
I see these most often on a EC2 PV instance's console when I'm watching it during instance termination. Apparently the (Ubuntu 14.04) kernel does something the xennet driver really doesn't like while shutting down.
toothrot 12y ago
"Rides the Rocket" is a reference to Quake. It's a pretty crude joke about getting shot by a rocket launcher in the classic Quake deathmatch. It's likely there because of the similar, "frags", which is what they called kills, gruesomely short for the same "fragmentation"

101 points by akerl_ 12y ago

Relevant Ubuntu bug: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1317811 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1317811 Relevant upstream discussion: http://www.spinics.net/lists/netdev/msg282340.html http://www.spinics.net/lists/netdev/msg282340.html

kazinator 12y ago

> This is pretty amazing. perf shows line numbers of those that can be instrumented directly, and those that can't in blue. That looks like it just came from debugging info. I.e. the numbered lines correspond to places where a debugger could put a breakpoint.

pyvpx 12y ago

is anyone aware of similar articles for any of the BSD flavors or other operating systems?

wmf 12y ago
Brendan Gregg has written many articles and a few books about DTrace which is included in FreeBSD.
brendangregg 12y ago
Depends how similar. This article was specifically about kernel line number and local variable tracing, which I've only seen Linux do. If you mean general kernel debugging, then my book on DTrace covers multiple operating systems including FreeBSD, and has around a thousand pages of examples. It would be nice if DTrace could add kernel line number and local variable tracing. Recently I've seen FreeBSD kernel builds where inlining has become more common than I've seen in the past, and missing kernel functions is becoming a bit of a nuisance. It's generally possible to work around it, but it would be nice to just trace lines and variables if needed.

derefr 12y ago

I see these most often on a EC2 PV instance's console when I'm watching it during instance termination. Apparently the (Ubuntu 14.04) kernel does something the xennet driver really doesn't like while shutting down.

toothrot 12y ago

"Rides the Rocket" is a reference to Quake. It's a pretty crude joke about getting shot by a rocket launcher in the classic Quake deathmatch. It's likely there because of the similar, "frags", which is what they called kills, gruesomely short for the same "fragmentation"