Hi, I'm using a mmap-intensive file server on a Dell Machine with 2.6.35.13. The partition is a RAID-0 mounted with ext4 and noatime. After a while using (about an hour) I get a lot of: INFO: task flush-8:16:6650 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. flush-8:16 D 0000000000000000 0 6650 2 0x00000000 ffff880400b0d980 0000000000000046 0000000000012500 ffff880400b0dfd8 ffff880400b0dfd8 ffff880418b34830 0000000000012500 0000000000012500 0000000000012500 ffff880418b34830 ffffffff81a11020 ffff880418b34ad8 Call Trace: [<ffffffff8151c837>] io_schedule+0x7b/0xc2 [<ffffffff8108fceb>] sync_page+0x41/0x45 [<ffffffff8151cb15>] __wait_on_bit_lock+0x45/0x8c [<ffffffff8108fcaa>] ? sync_page+0x0/0x45 [<ffffffff8108fc96>] __lock_page+0x63/0x6a [<ffffffff8104ed1c>] ? wake_bit_function+0x0/0x2a [<ffffffff8108fd88>] ? unlock_page+0x22/0x27 [<ffffffff81122f43>] ext4_da_writepages+0x516/0x8e1 [<ffffffff8103233f>] ? find_busiest_group+0x2e9/0x900 [<ffffffff81096720>] do_writepages+0x1c/0x25 [<ffffffff810df4d6>] writeback_single_inode+0xe8/0x329 [<ffffffff810dfaa9>] writeback_sb_inodes+0x14e/0x225 [<ffffffff810e02e1>] writeback_inodes_wb+0x146/0x156 [<ffffffff810e04a1>] wb_writeback+0x1b0/0x232 [<ffffffff81035288>] ? get_parent_ip+0x11/0x41 [<ffffffff810e065c>] wb_do_writeback+0x139/0x14f [<ffffffff810e06b0>] bdi_writeback_task+0x3e/0x112 [<ffffffff8104ec02>] ? bit_waitqueue+0x12/0xa3 [<ffffffff810a1800>] ? bdi_start_fn+0x0/0xd2 [<ffffffff810a1871>] bdi_start_fn+0x71/0xd2 [<ffffffff810a1800>] ? bdi_start_fn+0x0/0xd2 [<ffffffff8104e892>] kthread+0x7d/0x85 [<ffffffff810037d4>] kernel_thread_helper+0x4/0x10 [<ffffffff8104e815>] ? kthread+0x0/0x85 [<ffffffff810037d0>] ? kernel_thread_helper+0x0/0x10 The hardware is: 02:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1068E PCI-Express Fusion-MPT SAS (rev 08) The machine is RAID-0 with 2 450GB SAS 15K RPM hard drives. sd 0:2:1:0: [sdb] 1755840512 512-byte logical blocks: (898 GB/837 GiB) sd 0:2:1:0: [sdb] Write Protect is off sd 0:2:1:0: [sdb] Mode Sense: 1f 00 00 08 scsi 0:0:32:0: Attached scsi generic sg0 type 13 sd 0:2:1:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA sd 0:2:0:0: Attached scsi generic sg1 type 0 sd 0:2:1:0: Attached scsi generic sg2 type 0 Is there any other info I can provide you to help track this bug down? Cheers, -- Felipe Wilhelms Damasio TAGHOS - Tecnologia Rua Prof. Alvaro Alvim, 211 Porto Alegre - RS - (51) 3239-3180 www.taghos.com.br <http://www.taghos.com.br/> -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html