On Thu, May 27, 2021 at 10:33:13AM -0400, Qian Cai wrote: > > > On 5/27/2021 4:56 AM, Mike Rapoport wrote: > > Let's drop memblock=debug for now and add this instead: > > [ 0.000000][ T0] Booting Linux on physical CPU 0x0000000000 [0x503f0002] > [ 0.000000][ T0] Linux version 5.13.0-rc3-next-20210526+ (root@admin5) (gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0, GNU ld (GNU Binutils for Ubuntu) 2.34) #31 SMP Thu May 27 12:32:40 UTC 2021 > [ 0.000000][ T0] Inode-cache hash table entries: 4194304 (order: 9, 33554432 bytes, linear) > [ 0.000000][ T0] mem auto-init: stack:off, heap alloc:on, heap free:off > [ 0.000000][ T0] MEMBLOCK configuration: > [ 0.000000][ T0] memory size = 0x0000001ff0000000 reserved size = 0x0000000421e33ae8 > [ 0.000000][ T0] memory.cnt = 0xc > [ 0.000000][ T0] Memory: 777216K/133955584K available (17984K kernel code, 118722K rwdata, 4416K rodata, 6080K init, 67276K bss, 17379072K reserved, 0K cma-reserved) I still cannot understand where most of the memory disappeared, but it seems entirely different issue. > > Sorry, I've missed that the BUG is apparently triggered for pfn + i. Can > > you please try this instead: > > [ 259.216661][ T1417] test_pages_in_a_zone: pfn 8000 is not valid > [ 259.226547][ T1417] page:00000000f4aa8c5c is uninitialized and poisoned > [ 259.226560][ T1417] page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p)) Can you please try Anshuman's patch "arm64/mm: Drop HAVE_ARCH_PFN_VALID": https://lore.kernel.org/lkml/1621947349-25421-1-git-send-email-anshuman.khandual@xxxxxxx It seems to me that the check for memblock_is_memory() in arm64::pfn_valid() is what makes init_unavailable_range() to bail out for section parts that are not actually populated and then we have VM_BUG_ON_PAGE(PagePoisoned(p)) for these pages. -- Sincerely yours, Mike.
