Scaling of FreeBSD and Linux on 8 CPU systems

[V13]

On Monday 26 February 2007 13:31, Giorgos Keramidas wrote:
> [ Επειδή έχουμε καιρό να "πλακωθούμε" σε flames, και με τα καινούρια
>   "φρούτα" της λίστας δεν ψήνομαι ιδιαίτερα... ]
>
> Το παρακάτω κείμενο είναι ενδιαφέρον για το SMP support του FreeBSD,
> και τη σύγκριση που κάνει με το Linux:
>
>     http://people.freebsd.org/~kris/scaling/mysql.html

  An katalaba kala ayto ofeiletai sto oti afairethike to 'Giant Lock', to 
opoio prepei na'nai antistoixo me to 'Big Kernel Lock' (BKL) poy exei to 
linux kai epeidi metriastike h xrisi kapoion allon locks. To BKL den 
poly-xrisimopoieitai edo kai arketo kairo, eno ta ypoloipa locks toy linux 
einai per subsystem kai ginetai synexhs prospatheia na metriastoyn...

  Pera apo ayto, AFAIK to linux aksiopoiei arketa kala tis CPUs mias kai exei 
per-cpu kernel threads gia diafora asynxrona yposystimata (otidipote sygxrono 
enoeitai oti paei per-cpu, afoy kaleitai amesa apo to kathe process) kai sta 
opoia to locking metriazetai arketa kala... Apo tote poy egine o preemptive 
linux kernel, tetoia problimata beltiothikan arketa.

  Yparxei kapoio antistoixo sygkritiko gia alla themata pera ths MySQL, h 
opoia <flame> os gnoston den einai kai oti sobarotero yparxei </flame>? Opos 
edeikse kai o madf, h postgres einai poly kalyterh gia tetoia tests.

  Enalaktika tha mporoyses na xrisimopoieis 8+ diaforetika instances ths 
mysql, oste na apofygeis problimata apo xrisi semaphores kai na anagkazeis to 
systima na'nai se full forto.

  Telos, exo tin entyposi oti den anaferei poythena pos akribos itan o linux 
kernel. Preemptive? I/O scheduler? Ayta ta 2 mporoyn na kanoyn terastia 
diafora, eidika se kakogrameno software...

> Γιώργος
<<V13>>