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: Sun, 26 Jan 2014 00:51:23 -0800 From: Yinghai Lu <yinghai@...nel.org> To: Ingo Molnar <mingo@...nel.org> Cc: David Rientjes <rientjes@...gle.com>, Dave Jones <davej@...hat.com>, "the arch/x86 maintainers" <x86@...nel.org>, Linux Kernel <linux-kernel@...r.kernel.org> Subject: Re: disabled APICs being counted as processors ? On Sun, Jan 26, 2014 at 12:36 AM, Ingo Molnar <mingo@...nel.org> wrote: > > No, this message is printed in prefill_possible_map() which > _generates_ cpu_possible_map, so '8' is the number of bits in > cpu_possible_map. > > So the problem is that the counting of disabled but hotpluggable CPUs > is over-eager. Since I haven't actually seen _true_ hotplug CPU > hardware yet, I'd argue we do the change below - allocating space for > never-present CPUs is stupid. If there's true hot-plug CPUs around > that could come online after we've booted, then we want to know about > them explicitly. > > > diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c > index a32da80..75a351a 100644 > --- a/arch/x86/kernel/smpboot.c > +++ b/arch/x86/kernel/smpboot.c > @@ -1223,10 +1223,7 @@ __init void prefill_possible_map(void) > i = setup_max_cpus ?: 1; > if (setup_possible_cpus == -1) { > possible = num_processors; > -#ifdef CONFIG_HOTPLUG_CPU > - if (setup_max_cpus) > - possible += disabled_cpus; > -#else > +#ifndef CONFIG_HOTPLUG_CPU > if (possible > i) > possible = i; > #endif Agreed. Most happens when one BIOS support different configuration. Like system support 10 cores cpu and 15 cores cpus or system could be configured with 4 sockets or 8 sockets Thanks Yinghai -- 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