Ted Ts'o wrote: > Most files won't, but consider a postinstall script which needs to > scan/index a documentation file, or simply run one or more binaries > that was just installed. I can definitely imagine situations where > using POSIX_FADV_DONTNEED could actually hurt performance.
Hmm. Maybe file triggers could suppress DONTNEED. A nice side-effect might be to encourage use of file triggers. :) > If you are only installing a one or a few packages, and/or you can > somehow divine the user's intention that they will very shortly use > the file --- for example, if dpkg is being launched via packagekit to > install some font or codec, then using POSIX_FADV_DONTNEED is probably > the wrong answer. Even then, documentation extracted to /usr/share/doc doesn't need to be cached. I suppose some timing and tweaking would be needed. The cases to optimize most for imho are 1) initial installation (would use --force-unsafe-io) 2) apt-get dist-upgrade; xterm 3) apt-get install openoffice.org; oowriter 4) apt-get build-dep <anything>; dpkg-buildpackage since these are the most painful when they are slow. So I agree, this is not cut and dry. But being able to use the same function and have it (hopefully) do something roughly sane on a variety of kernels is very appealing. Jonathan -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20101129160613.gd8...@burratino
