Re: Expensiveness of searching load-path

kkm> Some time ago, Martin Buchholz wrote... kkm> |+ kkm> | My XEmacs packages are installed on a Linux machine. kkm> | Those packages are used from both Linux and from Solaris. kkm> | The Linux NFS server is notoriously slow. kkm> | Each find-file of a C source file on Solaris was annoyingly slow. kkm> | I tracked it down to this ancient code in one of my cc-mode hooks: kkm> | kkm> | (ignore-errors (require 'cc-lobotomy) ...) kkm> | kkm> | There is no such .el file on my load-path, so a full load-path search kkm> | was performed for every find-file. kkm> I think that Fload may be hacked so it caches misses. If the cache kkm> is flushed on every redisplay, this is pretty safe, but would greatly kkm> help avoid problems like this. Maybe flushing may be done even more kkm> intelligently. The current caching algorithm is actually quite reasonable. It just degrades when the number of directories in the search path grows without bound. (length load-path) ==> 83 kkm> At all, stats on NFS are known to be very expensive. XEmacs probably kkm> needs some general filesystem caching mechanism. My main point is that many of our users will have to wait an extra 10 seconds at startup, or whenever searching for a lisp library that is not found. Neither is acceptable. Martin ObBench: Packages initialization adds 12 sec to XEmacs startup time. The sleep's below are for Solaris/Linux NFS caches to time out. $ repeat 10 time env EMACSPACKAGEPATH=/root ./xemacs -no-site-file -no-init-file -f kill-emacs && sleep 60 env EMACSPACKAGEPATH=/root ./xemacs -no-site-file -no-init-file -f kill-emacs 0.27s user 0.11s system 2% cpu 16.065 total env EMACSPACKAGEPATH=/root ./xemacs -no-site-file -no-init-file -f kill-emacs 0.32s user 0.06s system 2% cpu 13.674 total env EMACSPACKAGEPATH=/root ./xemacs -no-site-file -no-init-file -f kill-emacs 0.35s user 0.07s system 2% cpu 16.332 total env EMACSPACKAGEPATH=/root ./xemacs -no-site-file -no-init-file -f kill-emacs 0.31s user 0.09s system 2% cpu 17.360 total env EMACSPACKAGEPATH=/root ./xemacs -no-site-file -no-init-file -f kill-emacs 0.34s user 0.14s system 2% cpu 17.274 total env EMACSPACKAGEPATH=/root ./xemacs -no-site-file -no-init-file -f kill-emacs 0.52s user 0.19s system 4% cpu 15.611 total env EMACSPACKAGEPATH=/root ./xemacs -no-site-file -no-init-file -f kill-emacs 0.47s user 0.19s system 10% cpu 6.358 total env EMACSPACKAGEPATH=/root ./xemacs -no-site-file -no-init-file -f kill-emacs 0.28s user 0.10s system 2% cpu 15.424 total env EMACSPACKAGEPATH=/root ./xemacs -no-site-file -no-init-file -f kill-emacs 0.34s user 0.19s system 3% cpu 17.472 total $ repeat 10 time ./xemacs -no-site-file -no-init-file -f kill-emacs && sleep 60 ./xemacs -no-site-file -no-init-file -f kill-emacs 0.92s user 0.23s system 4% cpu 26.682 total ./xemacs -no-site-file -no-init-file -f kill-emacs 0.65s user 0.31s system 3% cpu 25.849 total ./xemacs -no-site-file -no-init-file -f kill-emacs 0.52s user 0.26s system 2% cpu 26.787 total ./xemacs -no-site-file -no-init-file -f kill-emacs 0.83s user 0.25s system 4% cpu 24.658 total ./xemacs -no-site-file -no-init-file -f kill-emacs 0.67s user 0.24s system 3% cpu 24.445 total ./xemacs -no-site-file -no-init-file -f kill-emacs 0.84s user 0.24s system 3% cpu 28.127 total ./xemacs -no-site-file -no-init-file -f kill-emacs 0.68s user 0.25s system 3% cpu 24.599 total ./xemacs -no-site-file -no-init-file -f kill-emacs 0.49s user 0.18s system 2% cpu 23.756 total ./xemacs -no-site-file -no-init-file -f kill-emacs 0.76s user 0.30s system 4% cpu 21.710 total