| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Tue, 7 Nov 2006 21:26:14 +0000 From: Pavel Machek <pavel@....cz> To: Mikulas Patocka <mikulas@...ax.karlin.mff.cuni.cz> Cc: Albert Cahalan <acahalan@...il.com>, linux-kernel@...r.kernel.org Subject: Re: 2048 CPUs [was: Re: New filesystem for Linux] Hi! > >The SGI Altix can have 2048 CPUs. > > And does it run one image of Linux? Or more images each > on few cpus? > > How do they solve problem with spinlock livelocks? > > If time-spent-outside-spinlock/time-spent-in-spinlock < > number-of-cpus, the spinlock livelock may happen --- > this condition is not true normally with 2 or 4 cpus, > but for that high amount of cpus, there is a danger. Lets say time-spent-outside-spinlock == time-spent-in-spinlock and number-of-cpus == 2. 1 < 2 , so it should livelock according to you... ...but afaict this should work okay. Even if spinlocks are very unfair, as long as time-outside and time-inside comes in big chunks, it should work. If you are unlucky, one cpu may stall for a while, but... I see no livelock. -- Thanks for all the (sleeping) penguins. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists