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, 20 May 2008 18:14:58 -0700 From: Max Krasnyanskiy <maxk@...lcomm.com> To: Paul Jackson <pj@....com> CC: Peter Zijlstra <a.p.zijlstra@...llo.nl>, menage@...gle.com, mingo@...e.hu, linux-kernel@...r.kernel.org Subject: Re: IRQ affinities Paul Jackson wrote: > Peter wrote: >> That's a new feature; and its quite common that new features require >> code changes. > > It's common for new features to require code changes to take advantage > of the new features. > > It's less desirable that taking advantage of such new features breaks > existing, basically unrelated, code. > > My gut sense is that, in a misguided effort to find a "simple" answer > to irq distribution, we (well, y'all) are trying to attach this > feature to cpusets or cgroups. > > Let me ask a different question: > > What solutions would you (Max, Peter, Ingo, lurkers, ...) be > suggesting for this 'IRQ affinity' problem if cpusets and > cgroups didn't exist in any form whatsoever? As Peter explained I'm focusing on the "CPU isolation" aspect. ie Shielding a CPU (or a set of CPUs) from various kernel activities (load balancing, soft and hard irq handling, workqueues, etc). For the IRQs specifically all I need is to be able to tell the kernel to not route IRQs to certain CPUs. That's mostly works already via /proc/irq/N/smp_affinity, the problem is dynamically allocated irqs because /proc/irq/N directory does not exist until those IRQs are allocated/enabled. Originally I introduced global cpu_isolated_map. IRQ code was using that map to exclude CPU(s) from IRQ routing. What I realized now is that all I need is /proc/irq/default_smp_affinity. In other words I just need to export default mask used by the IRQ layer. I think this makes sense regardless of what cpuset based solution we'll come up with. Max -- 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