Emacs 24.1 performance regression.
 

Hi! I've run an emacs test (kind of), using, for example, file /usr/src/linux/crypto/testmgr.h (actually problem reproducible on other "large files" (several K of lines).

Steps to reproduce:
1. open file
2. push C-v (or PgDn) and do not release it till EOF reached
3. stuttering occurs (screen stops refreshing).

Actually in previous versions of Emacs i never seen such behaviour (in 23.1 i'm 100% confident).
If i open same file in vim, for example, it scrolls till EOF smoothly, never stutters.
Somebody, close to emacs development, has to check this out. I just tried it on latest 24.1.50 - problem persists, and -Q option gives same result.

Oh, nevermind. I've figured how to tweak it.

M-x customize-option
Customize variable: jit-lock-chunk-size