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: Wed, 26 Mar 2008 16:40:26 -0500 (CDT) From: Alan Mayer <ajm@....com> To: Ingo Molnar <mingo@...e.hu> Cc: Alan Mayer <ajm@....com>, torvalds@...ux-foundation.org, linux-kernel list <linux-kernel@...r.kernel.org>, Robin Holt <holt@....com>, Jack Steiner <steiner@....com>, Russ Anderson <rja@....com> Subject: Re: [PATCH] x86_64: resize NR_IRQS for large machines (re-submit) On Wed, 26 Mar 2008, Ingo Molnar wrote: > > * Alan Mayer <ajm@....com> wrote: > > > On machines with very large numbers of cpus, tables that are > > dimensioned by NR_IRQS get very large, especially the irq_desc table. > > They are also very sparsely used. When the cpu count is > > > MAX_IO_APICS, use MAX_IO_APICS to set NR_IRQS, otherwise use NR_CPUS. > > thanks Alan, applied this in place of the other patch. > > this bit is still ugly: > > > -#define NR_IRQS (NR_VECTORS + (32 *NR_CPUS)) > > +#if NR_CPUS < MAX_IO_APICS > > +#define NR_IRQS (NR_VECTORS + (32 * NR_CPUS)) > > +#else > > +#define NR_IRQS (NR_VECTORS + (32 * MAX_IO_APICS)) > > +#endif > > #define NR_IRQ_VECTORS NR_IRQS > > but it doesnt really depart from the current status quo of huge > [NR_IRQS] arrays either. Patches that make NR_IRQS a variable are > welcome :) > > Ingo > Good luck with that. If i come up with something that's elegant enough to make it worth the risk, I'll let you know. Changing NR_IRQS to a variable touches every arch and a lot of drivers. Someone is bound to choke on it, so it has to be something worth fighting for. --ajm Lately it occurs to me, What a long, strange trip it's been. -- Alan J. Mayer SGI ajm@....com WORK: 651-683-3131 HOME: 651-407-0134 -- -- 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