Hi list - Getting sporadic page allocation failures in btrfs send. This happened once several weeks ago but was fine after a reboot; yesterday I did not reboot, but had the failure back-to-back trying to send two different snapshots. These are full sends, not incremental, of a bit over 600G of data. Test machine has 32G of RAM, with 21G of it free (not including cache): root@gwa-virt1:/data/images/.snapshots# free -m total used free shared buffers cached Mem: 32159 31789 369 0 0 21276 -/+ buffers/cache: 10513 21646 Swap: 0 0 0 In both cases (all three, really) the btrfs send failed a bit more than half of the way through the send (somewhere around the 380GB mark). Kern log snippets follow: Jan 12 14:05:36 gwa-virt1 kernel: [535523.627611] btrfs: page allocation failure: order:6, mode:0x104050 Jan 12 14:05:36 gwa-virt1 kernel: [535523.627622] CPU: 6 PID: 9642 Comm: btrfs Not tainted 3.13.0-031300rc7-generic #201401041835 Jan 12 14:05:36 gwa-virt1 kernel: [535523.627773] [<ffffffffa0142214>] ? btrfs_get_token_64+0x64/0xf0 [btrfs] Jan 12 14:05:36 gwa-virt1 kernel: [535523.627818] [<ffffffffa01876dd>] ? ulist_add_merge+0xcd/0x270 [btrfs] Jan 12 14:05:36 gwa-virt1 kernel: [535523.627860] [<ffffffffa01876dd>] ulist_add_merge+0xcd/0x270 [btrfs] Jan 12 14:05:36 gwa-virt1 kernel: [535523.627894] [<ffffffffa018615c>] find_parent_nodes+0x50c/0x6f0 [btrf ] Jan 12 14:05:36 gwa-virt1 kernel: [535523.627930] [<ffffffffa018e550>] ? compare_refs.isra.23+0x130/0x130 btrfs] Jan 12 14:05:36 gwa-virt1 kernel: [535523.627965] [<ffffffffa0187019>] iterate_extent_inodes+0xf9/0x270 [btrfs] Jan 12 14:05:36 gwa-virt1 kernel: [535523.628003] [<ffffffffa014b7a5>] ? free_extent_buffer+0x35/0x40 [btrfs] Jan 12 14:05:36 gwa-virt1 kernel: [535523.628037] [<ffffffffa018dc9d>] find_extent_clone.isra.26+0x26d/0x340 [btrfs] Jan 12 14:05:36 gwa-virt1 kernel: [535523.628072] [<ffffffffa0191207>] process_extent+0xd7/0x180 [btrfs] Jan 12 14:05:36 gwa-virt1 kernel: [535523.628107] [<ffffffffa01918ff>] changed_cb+0xdf/0x170 [btrfs] Jan 12 14:05:36 gwa-virt1 kernel: [535523.628141] [<ffffffffa0191ad2>] full_send_tree+0x142/0x280 [btrfs] Jan 12 14:05:36 gwa-virt1 kernel: [535523.628174] [<ffffffffa0191ccc>] ? send_subvol_begin+0xbc/0x2b0 [btrfs] Jan 12 14:05:36 gwa-virt1 kernel: [535523.628209] [<ffffffffa0191fa0>] send_subvol+0xe0/0xf0 [btrfs] Jan 12 14:05:36 gwa-virt1 kernel: [535523.628244] [<ffffffffa01922f1>] btrfs_ioctl_send+0x341/0x520 [btrfs] Jan 12 14:05:36 gwa-virt1 kernel: [535523.628279] [<ffffffffa01606d3>] btrfs_ioctl+0x953/0xac0 [btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016512] btrfs: page allocation failure: order:5, mode:0x104050 Jan 12 21:34:00 gwa-virt1 kernel: [562448.016518] CPU: 4 PID: 18689 Comm: btrfs Not tainted 3.13.0-031300rc7-generic #201401041835 Jan 12 21:34:00 gwa-virt1 kernel: [562448.016597] [<ffffffffa0142214>] ? btrfs_get_token_64+0x64/0xf0 [btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016617] [<ffffffffa01876dd>] ? ulist_add_merge+0xcd/0x270 [btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016637] [<ffffffffa01876dd>] ulist_add_merge+0xcd/0x270 [btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016653] [<ffffffffa018615c>] find_parent_nodes+0x50c/0x6f0 [btrf ] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016669] [<ffffffffa018e550>] ? compare_refs.isra.23+0x130/0x130 btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016684] [<ffffffffa0187019>] iterate_extent_inodes+0xf9/0x270 [btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016700] [<ffffffffa014b7a5>] ? free_extent_buffer+0x35/0x40 [btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016716] [<ffffffffa018dc9d>] find_extent_clone.isra.26+0x26d/0x340 [btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016732] [<ffffffffa0191207>] process_extent+0xd7/0x180 [btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016747] [<ffffffffa01918ff>] changed_cb+0xdf/0x170 [btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016763] [<ffffffffa0191ad2>] full_send_tree+0x142/0x280 [btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016778] [<ffffffffa0191ccc>] ? send_subvol_begin+0xbc/0x2b0 [btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016794] [<ffffffffa0191fa0>] send_subvol+0xe0/0xf0 [btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016810] [<ffffffffa01922f1>] btrfs_ioctl_send+0x341/0x520 [btrfs] Jan 12 21:34:00 gwa-virt1 kernel: [562448.016826] [<ffffffffa01606d3>] btrfs_ioctl+0x953/0xac0 [btrfs] -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html