Phoronix vient de faire deux vidéos comparant les performances graphiques d'Ubuntu avec et sans l'application sur le noyau 2.6.37 d'un petit patch (un peu plus de 200 lignes) écrit par Mike Galbraith.
Comment ça marche ? Aucune idée, je ne mange pas de ce pain-là. Voici tout de même l'explication du monsieur :
Each task’s signal struct contains an inherited pointer to a refcounted autogroup struct containing a task group pointer, the default for all tasks pointing to the init_task_group. When a task calls __proc_set_tty(), the process wide reference to the default group is dropped, a new task group is created, and the process is moved into the new task group. Children thereafter inherit this task group, and increase it’s refcount. On exit, a reference to the current task group is dropped when the last reference to each signal struct is dropped. The task group is destroyed when the last signal struct referencing it is freed. At runqueue selection time, If a task has no cgroup assignment, it’s current autogroup is used.
Linus, quant à lui, trouve que c'est pas mal :
I'm also very happy with just what it does to interactive performance.
Admittedly, my "testcase" is really trivial (reading email in a
web-browser, scrolling around a bit, while doing a "make -j64" on the
kernel at the same time), but it's a test-case that is very relevant
for me. And it is a _huge_ improvement.
It's an improvement for things like smooth scrolling around, but what
I found more interesting was how it seems to really make web pages
load a lot faster. Maybe it shouldn't have been surprising, but I
always associated that with network performance. But there's clearly
enough of a CPU load when loading a new web page that if you have a
load average of 50+ at the same time, you _will_ be starved for CPU in
the loading process, and probably won't get all the http requests out
So I think this is firmly one of those "real improvement" patches.
Good job. Group scheduling goes from "useful for some specific server
loads" to "that's a killer feature".
J'imagine que ça va tomber dans un PPA quelconque d'ici pas longtemps. D'ailleurs, je bave un peu.
L'article de Phoronix : http://www.phoronix.com/scan.php?page=article&item=linux(...)
Et chez Korben : http://www.korben.info/un-patch-qui-boost-les-performances-d(...)