Very very slow buffer switching

[nick rothwell]

It takes 2 or 3 seconds to switch from one buffer to another. That's a lot
of CPU cycles. Any idea what's going on? It might be Clojure/cider-related,
but it's slow even switching between README files. It's been slow for a
while, but this latest beta seems to have made it worse.

I'm on BETA27, Emacs 24.5.1 (MacPorts).

[Sean Corfield]

I’ve only seen this happen (with 1.0beta27) if I’ve a) had Emacs open for several days and b) been doing a _lot_ of magit operations across multiple branches. Usually I notice magit operations getting slower first, then gradually most things get slower. M-x kill-emacs and a restart cures it.

Do you see memory usage increase over time for Emacs?

Is it fast when you first start it up? i.e., does it slow down over time?

Sean

It takes 2 or 3 seconds to switch from one buffer to another. That's a lot of CPU cycles. Any idea what's going on? It might be Clojure/cider-related, but it's slow even switching between README files. It's been slow for a while, but this latest beta seems to have made it worse.
I'm on BETA27, Emacs 24.5.1 (MacPorts).

[nick rothwell]

OK - yes, seems fast on a restart; will keep an eye on it. I've been
suspecting magit as well.

I was seeing a two-second CPU spike on buffer change, suggesting it's not a
memory problem directly (unlikely with 16GB of RAM and an SSD), but will
keep an eye on memory usage as well.