GNOME Bugzilla – Bug 655850
Initial search in activities overview is slow due to I/O
Last modified: 2012-11-07 14:45:18 UTC
This is my biggest gripe with gnome-shell right now: on anything but the fastest machine with a solid state drive, on the first attempt you make at searching/launching an application or file, it will lag significantly for a few seconds. My guess is that it only parses all the application .desktop files at that moment when you run a search for the first time, with disastrous consequences in terms of reactivity. This may seem trivial, but many users get annoyed at this problem especially in cases where you logout/switch users often. I'm wondering if there would be some way of lazy-loading this stuff in a background process on startup (when the gnome session i/o is done), instead of waiting on the user to bump into this problem?
Another possible (maybe complementary) approach would be to discard searches of less than 3 characters (one could say the search results would be too many/imprecise anyway) thus preventing "hammering" the search system and also buying some time for it to do its I/O work.
Can you make sure it's due to IO? Does the disk light blink a ton? Otherwise, this is a dup of #647778.
I'm not sure. I just did some more testing, and the IO happens only on the first login (or 'echo 3 > /proc/sys/vm/drop_caches' and restart the shell). So, - there is IO - if you logout and relogin without dropping caches, the initial search slowdown will happen... so it looks like you might be right about this being a potential duplicate of bug #647778. I just find it a bit surprising that IO would not have anything to do with it.
Hm, I think my previous comment is unclear. - on a warm start, the initial search is slow but there is no IO - on a cold start, the initial search is slow and there is IO
I mentioned this in bug 655811 too, but how big is your ~/.local/share/recently-used.xbel? I notice search gets slow(er) when this file is large (and useless when files listed in there no longer exist, but that is bug 653064)
Hey John, somehow I missed your question. My recently-used.xbel file is not unusually large (to gnome standards): 360K. Still seeing this stuff on 3.2. Any netbook or older computer (with IDE hard drives/a slower GPU) will easily reproduce this.
From my tests, in 3.6 there is no more noticeable lag anymore when searching, even on a cold start. The only remaining lag is the very first time you open the Activities overview on a cold start, about 1-2 seconds, but I guess I can live with that.
Well, there's no more lag for searching, that's true. But the first time I open the Activities overview on my laptop, now the whole UI is unresponsive for about 7-10 seconds. :-| The system looks completely hanged.
Follow-up in bug #687849.