Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1360554
| From | Thomas Gleixner <tglx@linutronix.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: 4.5.0+ panic when setup loop device |
| Date | 2016-03-18 13:00 +0100 |
| Message-ID | <re1eq-5aP-7@gated-at.bofh.it> (permalink) |
| References | <rddrk-53G-5@gated-at.bofh.it> <rdlyy-2jP-3@gated-at.bofh.it> <rdvod-yw-1@gated-at.bofh.it> <rdCSL-5Ht-39@gated-at.bofh.it> <rdU3g-vw-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Fri, 18 Mar 2016, Mike Galbraith wrote: > On Thu, 2016-03-17 at 10:52 +0100, Peter Zijlstra wrote: > > > Andreas; Borislav said to Cc you since you wrote all this. > > The issue is that Linux assumes: > > > > > nr_logical_cpus = nr_cores * nr_siblings > > It also seems to now assume that if SMT is possible, it's enabled. > > Below is my 8 socket DL980 G7, which has SMT turned off for RT testing, > booting NOPREEMPT master tuned for maximum bloat ala distro and getting > confused by me telling it (as always) nr_cpus=64. Bad juju ensues. :) Does the patch below fix the wreckage? diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 643dbdccf4bc..c5ac71276076 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -319,7 +319,7 @@ static void __init smp_init_package_map(void) * might change in the future.... */ ncpus = boot_cpu_data.x86_max_cores * smp_num_siblings; - __max_logical_packages = DIV_ROUND_UP(nr_cpu_ids, ncpus); + __max_logical_packages = DIV_ROUND_UP(total_cpus, ncpus); /* * Possibly larger than what we need as the number of apic ids per
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Re: 4.5.0+ panic when setup loop device Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-03-18 05:20 +0100
Re: 4.5.0+ panic when setup loop device Peter Zijlstra <peterz@infradead.org> - 2016-03-18 09:00 +0100
Re: 4.5.0+ panic when setup loop device Peter Zijlstra <peterz@infradead.org> - 2016-03-18 11:20 +0100
Re: 4.5.0+ panic when setup loop device Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-03-18 13:40 +0100
Re: 4.5.0+ panic when setup loop device Peter Zijlstra <peterz@infradead.org> - 2016-03-18 14:40 +0100
Re: 4.5.0+ panic when setup loop device Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-03-18 15:10 +0100
Re: 4.5.0+ panic when setup loop device Thomas Gleixner <tglx@linutronix.de> - 2016-03-18 13:00 +0100
Re: 4.5.0+ panic when setup loop device Mike Galbraith <umgwanakikbuti@gmail.com> - 2016-03-18 13:50 +0100
[tip:x86/urgent] x86/topology: Use total_cpus not nr_cpu_ids for logical packages tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-03-19 10:40 +0100
csiph-web