On Wed, 2015-10-14 at 12:20 -0400, shrybman wrote: > All 3.4-rc kernels I have tried displayed this issue.
> This report looks similar https://lkml.org/lkml/2015/9/26/165. > I also have a Core 2 cpu on a Asus P5B (not deluxe) board. > ... > ACPI: Core revision 20150818 > ACPI: 1 ACPI AML tables successfully acquired and loaded > Mount-cache hash table entries: 8192 (order: 4, 65536 bytes) > Mountpoint-cache hash table entries: 8192 (order: 4, 65536 bytes) > CPU: Physical Processor ID: 0 > CPU: Processor Core ID: 0 > mce: CPU supports 6 MCE banks > CPU0: Thermal monitoring enabled (TM2) > process: using mwait in idle threads > Last level iTLB entries: 4KB 128, 2MB 4, 4MB 4 > Last level dTLB entries: 4KB 256, 2MB 0, 4MB 32, 1GB 0 > Freeing SMP alternatives memory: 20K (ffffffff819b5000 - ffffffff819ba000) > ftrace: allocating 18583 entries in 73 pages > ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1 > smpboot: CPU0: Intel(R) Core(TM)2 CPU 6400 @ 2.13GHz (fam: 06, > model: 0f, stepping: 06) > Performance Events: PEBS fmt0-, 4-deep LBR, Core2 events, Intel PMU driver. > perf_event_intel: PEBS disabled due to CPU errata > ... version: 2 > ... bit width: 40 > ... generic registers: 2 > ... value mask: 000000ffffffffff > ... max period: 000000007fffffff > ... fixed-purpose events: 3 > ... event mask: 0000000700000003 > x86: Booting SMP configuration: > .... node #0, CPUs: #1 > smpboot: do_boot_cpu failed(-1) to wakeup CPU#1 > x86: Booted up 1 node, 1 CPUs > smpboot: Total of 1 processors activated (4272.42 BogoMIPS) > devtmpfs: initialized > I took a guess and got lucky. > Reverting "x86/smpboot: Remove APIC.wait_for_init_deassert and atomic > init_deasserted" resolved the issue. As a followup, I updated compiler to gcc-5.2 (no help or change). I also tried suggested /vmlinuz-4.3.0-rc3 parameter in grub: "cpu_init_udelay=10000" which did not help getting missing CPU back online. So all linux-4.3.0-rc[15] lose the second CPU core. Don -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
