On Mon, Jul 26, 2021 at 02:23:20PM -0700, Matt Turner wrote: > On Mon, Jul 26, 2021 at 1:06 PM Mike Rapoport <rppt@xxxxxxxxxxxxx> wrote: > > > > Hi Matt, > > > > On Mon, Jul 26, 2021 at 12:27:50PM -0700, Matt Turner wrote: > > > Reply-To: > > > > > > Hi Mike! > > > > > > Since commit fa3354e4ea39 (mm: free_area_init: use maximal zone PFNs rather > > > than zone sizes), I get the following BUG on Alpha (an AlphaServer ES47 Marvel) > > > and loading userspace leads to a segfault: > > > > > > (I didn't notice this for a long time because of other unrelated regressions, > > > the pandemic, changing jobs, ...) > > > > I suspect there will be more surprises down the road :) > > > > > BUG: Bad page state in process swapper pfn:2ffc53 > > > page:fffffc000ecf14c0 refcount:0 mapcount:1 mapping:0000000000000000 index:0x0 > > > flags: 0x0() > > > raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > > > raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > > > page dumped because: nonzero mapcount Modules linked in: > > > CPU: 0 PID: 0 Comm: swapper Not tainted 5.7.0-03841-gfa3354e4ea39-dirty #26 > > > fffffc0001b5bd68 fffffc0001b5be80 fffffc00011cd148 fffffc000ecf14c0 > > > fffffc00019803df fffffc0001b5be80 fffffc00011ce340 fffffc000ecf14c0 > > > 0000000000000000 fffffc0001b5be80 fffffc0001b482c0 fffffc00027d6618 > > > fffffc00027da7d0 00000000002ff97a 0000000000000000 fffffc0001b5be80 > > > fffffc00011d1abc fffffc000ecf14c0 fffffc0002d00000 fffffc0001b5be80 > > > fffffc0001b2350c 0000000000300000 fffffc0001b48298 fffffc0001b482c0 > > > Trace: > > > [<fffffc00011cd148>] bad_page+0x168/0x1b0 > > > [<fffffc00011ce340>] free_pcp_prepare+0x1e0/0x290 > > > [<fffffc00011d1abc>] free_unref_page+0x2c/0xa0 > > > [<fffffc00014ee5f0>] cmp_ex_sort+0x0/0x30 > > > [<fffffc00014ee5f0>] cmp_ex_sort+0x0/0x30 > > > [<fffffc000101001c>] _stext+0x1c/0x20 > > > > > > I haven't tried reproducing this on other machines or QEMU, but I'd be glad to > > > if that helps. > > > > If it's reproducible on QEMU I can debug it locally. > > > > > Any ideas? > > > > It seems like memory map is not properly initialized. Can you enable > > CONFIG_DEBUG_MEMORY_INIT and add mminit_debug=4 to the command line. The > > interesting part of the log would be before "Memory: xK/yK available ..." > > line. > > > > Hopefully it'll give some clues. > > Sure thing. Please find attached. > aboot: loading uncompressed vmlinuz-5.7.0-03841-gfa3354e4ea39-dirty... > aboot: loading compressed vmlinuz-5.7.0-03841-gfa3354e4ea39-dirty... > aboot: PHDR 0 vaddr 0xfffffc0001010000 offset 0xc0 size 0x17c5ae0 > aboot: bss at 0xfffffc00027d5ae0, size 0xe4ea0 > aboot: zero-filling 937632 bytes at 0xfffffc00027d5ae0 > aboot: loading initrd (5965252 bytes/5825 blocks) at 0xfffffc05ff2cc000 > aboot: starting kernel vmlinuz-5.7.0-03841-gfa3354e4ea39-dirty with arguments ro panic=5 domdadm root=/dev/md1 console=srm mminit_debug=4 > Linux version 5.7.0-03841-gfa3354e4ea39-dirty (mattst88@ivybridge) (gcc version 11.1.0 (Gentoo 11.1.0-r2 p3), GNU ld (Gentoo 2.36.1 p3) 2.36.1) #26 SMP Sun Jul 25 18:20:06 PDT 2021 > printk: bootconsole [srm0] enabled > Booting on Marvel variation Marvel/EV7 using machine vector MARVEL/EV7 from SRM > Major Options: SMP EV67 VERBOSE_MCHECK DEBUG_SPINLOCK MAGIC_SYSRQ > Command line: ro panic=5 domdadm root=/dev/md1 console=srm mminit_debug=4 > memcluster 0, usage 1, start 0, end 1984 > memcluster 1, usage 0, start 1984, end 1048576 > memcluster 2, usage 1, start 2097152, end 2097224 > memcluster 3, usage 0, start 2097224, end 3145728 > Initial ramdisk at: 0x(____ptrval____) (5965252 bytes) > Found an IO7 at PID 0 > Initializing IO7 at PID 0 > FIXME: disabling master aborts > FIXME: disabling master aborts > FIXME: disabling master aborts > FIXME: disabling master aborts > SMP: 2 CPUs probed -- cpu_present_mask = 3 > Zone ranges: > DMA [mem 0x0000000000f80000-0x00000fffffffdfff] > Normal empty > Movable zone start for each node > Early memory node ranges > node 0: [mem 0x0000000000f80000-0x00000001ffffffff] > node 0: [mem 0x0000000400090000-0x00000005ffffffff] I think that the issue is that memory marked as used in memcluster is never added to memblock and it skews node/zone sizing calculations. Can you try this patch: diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c index 7d56c217b235..b4fbbba30aa2 100644 --- a/arch/alpha/kernel/setup.c +++ b/arch/alpha/kernel/setup.c @@ -319,18 +319,19 @@ setup_memory(void *kernel_end) i, cluster->usage, cluster->start_pfn, cluster->start_pfn + cluster->numpages); - /* Bit 0 is console/PALcode reserved. Bit 1 is - non-volatile memory -- we might want to mark - this for later. */ - if (cluster->usage & 3) - continue; - end = cluster->start_pfn + cluster->numpages; if (end > max_low_pfn) max_low_pfn = end; memblock_add(PFN_PHYS(cluster->start_pfn), cluster->numpages << PAGE_SHIFT); + + /* Bit 0 is console/PALcode reserved. Bit 1 is + non-volatile memory -- we might want to mark + this for later. */ + if (cluster->usage & 3) + memblock_reserve(PFN_PHYS(cluster->start_pfn), + cluster->numpages << PAGE_SHIFT); } /* > Initmem setup node 0 [mem 0x0000000000f80000-0x00000005ffffffff] > percpu: Embedded 8 pages/cpu s27648 r8192 d29696 u65536 > Built 1 zonelists, mobility grouping on. Total pages: 2070535 > Kernel command line: ro panic=5 domdadm root=/dev/md1 console=srm mminit_debug=4 > Dentry cache hash table entries: 2097152 (order: 11, 16777216 bytes, linear) > Inode-cache hash table entries: 1048576 (order: 10, 8388608 bytes, linear) > Sorting __ex_table... > mem auto-init: stack:off, heap alloc:off, heap free:off > BUG: Bad page state in process swapper pfn:2ffc3f > page:fffffc000ecf0fc0 refcount:0 mapcount:1 mapping:0000000000000000 index:0x0 > flags: 0x0() > raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > page dumped because: nonzero mapcount > Modules linked in: > CPU: 0 PID: 0 Comm: swapper Not tainted 5.7.0-03841-gfa3354e4ea39-dirty #26 > fffffc0001b5bd68 fffffc0001b5be80 fffffc00011cd148 fffffc000ecf0fc0 > fffffc00019803df fffffc0001b5be80 fffffc00011ce340 fffffc000ecf0fc0 > 0000000000000000 fffffc0001b5be80 fffffc0001b482c0 fffffc00027d6618 > fffffc00027da7d0 00000000002ff966 0000000000000000 fffffc0001b5be80 > fffffc00011d1abc fffffc000ecf0fc0 fffffc0002d00000 fffffc0001b5be80 > fffffc0001b2350c 0000000000300000 fffffc0001b48298 fffffc0001b482c0 > Trace: > [<fffffc00011cd148>] bad_page+0x168/0x1b0 > [<fffffc00011ce340>] free_pcp_prepare+0x1e0/0x290 > [<fffffc00011d1abc>] free_unref_page+0x2c/0xa0 > [<fffffc00014ee5f0>] cmp_ex_sort+0x0/0x30 > [<fffffc00014ee5f0>] cmp_ex_sort+0x0/0x30 > [<fffffc000101001c>] _stext+0x1c/0x20 ... > Memory: 16496504K/16760768K available (8698K kernel code, 12790K rwdata, 2544K rodata, 304K init, 915K bss, 256576K reserved, 0K cma-reserved) -- Sincerely yours, Mike.
