2015-05-20 1:01 GMT+08:00 Martin Pitt <martin.p...@ubuntu.com>: > Hey cee1, > > cee1 [2015-05-18 23:52 +0800]: >> At the first glance, I find ureadahead has some difference compared >> with the readahead once in systemd, IIRC: > > Yes, for sure. systemd's was improved quite a bit. ureadahead is > mostly unmaintained, but it works well enough so we didn't bother to > put work into it until someone actually complains :-) > >> 1. ureadahead.service is in default.target, which means ureadahead >> starts later than systemd's? > > That mostly means that it's not started with e. g. emergency or > rescue. It still starts early (DefaultDependencies=false). > >> 2. The original systemd readahead has "collect" and "replay" two >> services, and these are done in ureadahead.service? > > Yes. > >> 3. IIRC, The original systemd readahead uses madvise(); ureadahead >> uses readahead() >> 4. The original systemd readahead uses fanotify() to get the list of >> accessed files; ureadahead use fsnotify > > I haven't verified these, but this sounds correct. ureadahead is > really old, presumably the newer features like fanotify weren't > available back then.
I tried ureadahead, but got following error: """write(2, "ureadahead: Error while tracing:"..., 59ureadahead: Error while tracing: No such file or directory""" Needs an out-of-tree kernel patch? -- Regards, - cee1 _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
