On Tue, 2019-08-06 at 21:32 +1000, Michael Ellerman wrote: > Chris Packham <chris.pack...@alliedtelesis.co.nz> writes: > > > > On Mon, 2019-08-05 at 14:06 +1200, Chris Packham wrote: > > > > > > Hi All, > > > > > > I have a custom board that uses the Freescale/NXP T2080 SoC. > > > > > > The board boots fine using v4.19.60 but when I use v5.1.21 it > > > locks > > > up > > > waiting for the other CPUs to come online (earlyprintk output > > > below). > > > If I set maxcpus=0 then the system boots all the way through to > > > userland. The same thing happens with 5.3-rc2. > > > > > > The defconfig I'm using is > > > https://gist.github.com/cpackham/f24d0b426f3 > > > de0eaaba17b82c3528a9d it was updated from the working v4.19.60 > > > defconfig using make olddefconfig. > > > > > > Does this ring any bells for anyone? > > > > > > I haven't dug into the differences between the working an non- > > > working > > > versions yet. I'll start looking now. > > I've bisected this to the following commit > Thanks that's super helpful. > > > > > commit ed1cd6deb013a11959d17a94e35ce159197632da > > Author: Christophe Leroy <christophe.le...@c-s.fr> > > Date: Thu Jan 31 10:08:58 2019 +0000 > > > > powerpc: Activate CONFIG_THREAD_INFO_IN_TASK > > > > This patch activates CONFIG_THREAD_INFO_IN_TASK which > > moves the thread_info into task_struct. > > > > I'll be the first to admit this is well beyond my area of knowledge > > so > > I'm unsure what about this patch is problematic but I can be fairly > > sure that a build immediately before this patch works while a build > > with this patch hangs. > It makes a pretty fundamental change to the way the kernel stores > some > information about each task, moving it off the stack and into the > task > struct. > > It definitely has the potential to break things, but I thought we had > reasonable test coverage of the Book3E platforms, I have a p5020ds > (e5500) that I boot as part of my CI. > > Aha. If I take your config and try to boot it on my p5020ds I get the > same behaviour, stuck at SMP bringup. So it seems it's something in > your > config vs corenet64_smp_defconfig that is triggering the bug. > > Can you try bisecting what in the config triggers it? > > To do that you checkout ed1cd6deb013a11959d17a94e35ce159197632da, > then > you build/boot with corenet64_smp_defconfig to confirm it works. Then > you use tools/testing/ktest/config-bisect.pl to bisect the changes in > the .config. > > cheers >
The difference between a working and non working defconfig is CONFIG_PREEMPT specifically CONFIG_PREEMPT=y makes my system hang at boot. Is that now intentionally prohibited on 64-bit powerpc? > > > > > > > > Booting... > > > MMU: Supported page sizes > > > 4 KB as direct > > > 2048 KB as direct & indirect > > > 4096 KB as direct > > > 16384 KB as direct > > > 65536 KB as direct > > > 262144 KB as direct > > > 1048576 KB as direct > > > MMU: Book3E HW tablewalk enabled > > > Linux version 5.1.21-at1+ (@chrisp-dl) (gcc version 4.9.3 > > > (crosstool- > > > NG > > > crosstool-ng-1.22.0)) #24 SMP PREEMPT Mon Aug 5 01:42:00 UTC 2019 > > > Found initrd at 0xc00000002f045000:0xc000000030000000 > > > Using CoreNet Generic machine description > > > Found legacy serial port 0 for /soc@ffe000000/serial@11c500 > > > mem=ffe11c500, taddr=ffe11c500, irq=0, clk=300000000, speed=0 > > > Found legacy serial port 1 for /soc@ffe000000/serial@11c600 > > > mem=ffe11c600, taddr=ffe11c600, irq=0, clk=300000000, speed=0 > > > Found legacy serial port 2 for /soc@ffe000000/serial@11d500 > > > mem=ffe11d500, taddr=ffe11d500, irq=0, clk=300000000, speed=0 > > > Found legacy serial port 3 for /soc@ffe000000/serial@11d600 > > > mem=ffe11d600, taddr=ffe11d600, irq=0, clk=300000000, speed=0 > > > printk: bootconsole [udbg0] enabled > > > CPU maps initialized for 2 threads per core > > > (thread shift is 1) > > > Allocated 1856 bytes for 8 pacas > > > ----------------------------------------------------- > > > phys_mem_size = 0x100000000 > > > dcache_bsize = 0x40 > > > icache_bsize = 0x40 > > > cpu_features = 0x00000003009003b6 > > > possible = 0x00000003009003b6 > > > always = 0x00000003008003b4 > > > cpu_user_features = 0xdc008000 0x08000000 > > > mmu_features = 0x000a0010 > > > firmware_features = 0x0000000000000000 > > > ----------------------------------------------------- > > > CoreNet Generic board > > > barrier-nospec: using isync; sync as speculation barrier > > > barrier-nospec: patched 412 locations > > > Top of RAM: 0x100000000, Total RAM: 0x100000000 > > > Memory hole size: 0MB > > > Zone ranges: > > > DMA [mem 0x0000000000000000-0x000000007fffefff] > > > Normal [mem 0x000000007ffff000-0x00000000ffffffff] > > > Movable zone start for each node > > > Early memory node ranges > > > node 0: [mem 0x0000000000000000-0x00000000ffffffff] > > > Initmem setup node 0 [mem 0x0000000000000000-0x00000000ffffffff] > > > On node 0 totalpages: 1048576 > > > DMA zone: 7168 pages used for memmap > > > DMA zone: 0 pages reserved > > > DMA zone: 524287 pages, LIFO batch:63 > > > Normal zone: 7169 pages used for memmap > > > Normal zone: 524289 pages, LIFO batch:63 > > > MMU: Allocated 2112 bytes of context maps for 255 contexts > > > percpu: Embedded 22 pages/cpu s49304 r0 d40808 u131072 > > > pcpu-alloc: s49304 r0 d40808 u131072 alloc=1*1048576 > > > pcpu-alloc: [0] 0 1 2 3 4 5 6 7 > > > Built 1 zonelists, mobility grouping on. Total pages: 1034239 > > > Kernel command line: console=ttyS0,115200 root=/dev/ram0 > > > releasefile=linuxbox_ppc64_e6500mc-tb233.rel bootversion=6.2.7 > > > loglevel=8 mtdoops.mtddev=errlog > > > mtdparts=fff800000.flash:4088M(user),8M(errlog) > > > earlyprintk=ttyS0,115200 real_init= > > > /bin/sh securitylevel=1 reladdr=0x1000000,1522523 > > > printk: log_buf_len individual max cpu contribution: 4096 bytes > > > printk: log_buf_len total cpu_extra contributions: 28672 bytes > > > printk: log_buf_len min size: 16384 bytes > > > printk: log_buf_len: 65536 bytes > > > printk: early log buf free: 12412(75%) > > > Dentry cache hash table entries: 524288 (order: 10, 4194304 > > > bytes) > > > Inode-cache hash table entries: 262144 (order: 9, 2097152 bytes) > > > Memory: 3979284K/4194304K available (8704K kernel code, 1584K > > > rwdata, > > > 2496K rodata, 472K init, 299K bss, 215020K reserved, 0K cma- > > > reserved) > > > SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=8, Nodes=1 > > > rcu: Preemptible hierarchical RCU implementation. > > > rcu: RCU event tracing is enabled. > > > Tasks RCU enabled. > > > rcu: RCU calculated value of scheduler-enlistment delay is 25 > > > jiffies. > > > NR_IRQS: 512, nr_irqs: 512, preallocated irqs: 16 > > > mpic: Setting up MPIC " OpenPIC " version 1.2 at ffe040000, max > > > 8 > > > CPUs > > > mpic: ISU size: 512, shift: 9, mask: 1ff > > > mpic: Initializing for 512 sources > > > time_init: decrementer frequency = 37.500000 MHz > > > time_init: processor frequency = 1500.000000 MHz > > > clocksource: timebase: mask: 0xffffffffffffffff max_cycles: > > > 0x8a60dd6a9, max_idle_ns: 440795204056 ns > > > clocksource: timebase mult[1aaaaaab] shift[24] registered > > > clockevent: decrementer mult[999999a] shift[32] cpu[0] > > > pid_max: default: 32768 minimum: 301 > > > Mount-cache hash table entries: 8192 (order: 4, 65536 bytes) > > > Mountpoint-cache hash table entries: 8192 (order: 4, 65536 bytes) > > > e6500 family performance monitor hardware support registered > > > rcu: Hierarchical SRCU implementation. > > > smp: Bringing up secondary CPUs ...
