[OE-core] page allocation failures

[Ryan Meulenkamp]

Hi y'all,

I get page allocation failures which are not correct as far as I can see. Only a single page is requested,
albeit atomically. But it fails even though there are, in this case, 48 single page fragments available.
Why does it still fail though? What could be going wrong here?

[19119.398437] java: page allocation failure: order:0, mode:0x2080020(GFP_ATOMIC)
[19119.398437] CPU: 0 PID: 19293 Comm: java Not tainted 4.9.28+ #1
[19119.398437] Hardware name: Atmel AT91SAM9G45
[19119.398437] [<c000fa64>] (unwind_backtrace) from [<c000d520>] (show_stack+0x10/0x14)
[19119.398437] [<c000d520>] (show_stack) from [<c0088468>] (warn_alloc+0xf0/0x118)
[19119.398437] [<c0088468>] (warn_alloc) from [<c00887a4>] (__alloc_pages_nodemask+0x27c/0xa9c)
[19119.398437] [<c00887a4>] (__alloc_pages_nodemask) from [<c00891c8>] (__alloc_page_frag+0x140/0x174)
[19119.398437] [<c00891c8>] (__alloc_page_frag) from [<c0346600>] (__netdev_alloc_skb+0x98/0x100)
[19119.398437] [<c0346600>] (__netdev_alloc_skb) from [<c02eb7f8>] (macb_rx+0xc4/0x38c)
[19119.398437] [<c02eb7f8>] (macb_rx) from [<c02ec6a8>] (macb_poll+0x50/0x114)
[19119.398437] [<c02ec6a8>] (macb_poll) from [<c0351c90>] (net_rx_action+0x1b0/0x2a8)
[19119.398437] [<c0351c90>] (net_rx_action) from [<c001bd24>] (__do_softirq+0x128/0x268)
[19119.398437] [<c001bd24>] (__do_softirq) from [<c001c15c>] (irq_exit+0xbc/0xe0)
[19119.398437] [<c001c15c>] (irq_exit) from [<c004979c>] (__handle_domain_irq+0x64/0xd4)
[19119.398437] [<c004979c>] (__handle_domain_irq) from [<c000dfbc>] (__irq_svc+0x5c/0x90)
[19119.398437] [<c000dfbc>] (__irq_svc) from [<c024cc1c>] (gpio_to_desc+0xb0/0x11c)
[19119.398437] [<c024cc1c>] (gpio_to_desc) from [<c02c47e4>] (atmel_nand_enable+0x14/0x20)
[19119.398437] [<c02c47e4>] (atmel_nand_enable) from [<c02c4838>] (atmel_nand_cmd_ctrl+0x28/0x64)
[19119.398437] [<c02c4838>] (atmel_nand_cmd_ctrl) from [<c02bf688>] (nand_command_lp+0x110/0x314)
[19119.398437] [<c02bf688>] (nand_command_lp) from [<c02beab4>] (nand_do_read_ops+0x16c/0x578)
[19119.398437] [<c02beab4>] (nand_do_read_ops) from [<c02bf234>] (nand_read+0x5c/0x7c)
[19119.398437] [<c02bf234>] (nand_read) from [<c02b4db0>] (part_read+0x4c/0x84)
[19119.398437] [<c02b4db0>] (part_read) from [<c02b2634>] (mtd_read+0x9c/0xcc)
[19119.398437] [<c02b2634>] (mtd_read) from [<c02d2224>] (ubi_io_read+0x9c/0x2f8)
[19119.398437] [<c02d2224>] (ubi_io_read) from [<c02cf8a0>] (ubi_eba_read_leb+0x94/0x4b4)
[19119.398437] [<c02cf8a0>] (ubi_eba_read_leb) from [<c02ce54c>] (ubi_leb_read+0x74/0xb4)
[19119.398437] [<c02ce54c>] (ubi_leb_read) from [<c01bb5a0>] (ubifs_leb_read+0x28/0x74)
[19119.398437] [<c01bb5a0>] (ubifs_leb_read) from [<c01be260>] (fallible_read_node+0x40/0x164)
[19119.398437] [<c01be260>] (fallible_read_node) from [<c01c04a0>] (ubifs_tnc_locate+0xf8/0x1c0)
[19119.398437] [<c01c04a0>] (ubifs_tnc_locate) from [<c01b2844>] (do_readpage+0x180/0x44c)
[19119.398437] [<c01b2844>] (do_readpage) from [<c01b3d2c>] (ubifs_readpage+0x38/0x50c)
[19119.398437] [<c01b3d2c>] (ubifs_readpage) from [<c0083040>] (filemap_fault+0x46c/0x618)
[19119.398437] [<c0083040>] (filemap_fault) from [<c00a42ac>] (__do_fault+0x6c/0x108)
[19119.398437] [<c00a42ac>] (__do_fault) from [<c00a7c30>] (handle_mm_fault+0xb00/0x1464)
[19119.398437] [<c00a7c30>] (handle_mm_fault) from [<c00118a4>] (do_page_fault+0x220/0x2ac)
[19119.398437] [<c00118a4>] (do_page_fault) from [<c0009418>] (do_PrefetchAbort+0x3c/0xa0)
[19119.398437] [<c0009418>] (do_PrefetchAbort) from [<c000e504>] (ret_from_exception+0x0/0x1c)
[19119.398437] Exception stack(0xc72adfb0 to 0xc72adff8)
[19119.398437] dfa0:                                     ae878e4c b6fa71a4 00000001 b6851904
[19119.398437] dfc0: ae878e4c b6d9c3c4 00000000 b0ef2c00 b0ef2c00 b191f0c8 00000001 ae878e24
[19119.398437] dfe0: 00000001 ae878cd8 b6d05c38 b6851904 60000010 ffffffff
[19119.398437] Mem-Info:
[19119.398437] active_anon:25949 inactive_anon:47 isolated_anon:0
[19119.398437]  active_file:760 inactive_file:542 isolated_file:4
[19119.398437]  unevictable:435 dirty:0 writeback:0 unstable:0
[19119.398437]  slab_reclaimable:255 slab_unreclaimable:1023
[19119.398437]  mapped:1694 shmem:80 pagetables:199 bounce:0
[19119.398437]  free:768 free_pcp:26 free_cma:0
[19119.398437] Node 0 active_anon:103796kB inactive_anon:188kB active_file:3040kB inactive_file:2168kB unevictable:1740kB isolated(anon):0kB isolated(file):16kB mapped:6776kB dirty:0kB writeback:0kB shmem:320kB writeback_tmp:0kB unstable:0kB pages_scanned:252 all_unreclaimable? no
[19119.398437] Normal free:3072kB min:1408kB low:1760kB high:2112kB active_anon:103796kB inactive_anon:188kB active_file:3040kB inactive_file:2168kB unevictable:1740kB writepending:0kB present:131072kB managed:124364kB mlocked:1740kB slab_reclaimable:1020kB slab_unreclaimable:4092kB kernel_stack:1312kB pagetables:796kB bounce:0kB free_pcp:104kB local_pcp:104kB free_cma:0kB
[19119.398437] lowmem_reserve[]: 0 0
[19119.398437] Normal: 48*4kB (H) 16*8kB (H) 8*16kB (H) 12*32kB (H) 5*64kB (H) 3*128kB (H) 2*256kB (H) 2*512kB (H) 0*1024kB 0*2048kB 0*4096kB = 3072kB
1743 total pagecache pages
[19119.398437] 32768 pages RAM
[19119.398437] 0 pages HighMem/MovableOnly
[19119.398437] 1677 pages reserved


Some background information:
- Kernel version: linux-at91 v4.9.28
- Relevant configs:
  - SLAB allocator
  - Compaction and migration turned on
  - Swap turned off

Thanks in advance!

Ryan Meulenkamp