Hi Miklos, I'm running some tests with an NTFS formated USB 3.0 device. First, I flush any caches by running `echo 3 > /proc/sys/vm/drop_caches`. Next, I begin a copy of a 1.1 GB file to the device. I immediately attempt to hibernate the system, but the hibernate almost always fails. dmesg says: [ 170.410849] PM: Basic memory bitmaps created [ 170.410854] PM: Syncing filesystems ... done. [ 172.044468] Freezing user space processes ... [ 192.037863] Freezing of tasks failed after 20.00 seconds (1 tasks refusing to freeze, wq_busy=0): [ 192.037919] cp D 0000000000000000 0 2431 2332 0x00000004 [ 192.037930] ffff880139867bc8 0000000000000046 0000000000000286 ffff880142694ba0 [ 192.037944] ffff88013dbcdee0 ffff880139867fd8 ffff880139867fd8 ffff880139867fd8 [ 192.037957] ffff880148321fa0 ffff88013dbcdee0 ffff880139867bd8 ffff880142694ac0 [ 192.037971] Call Trace: [ 192.037981] [<ffffffff816f91d9>] schedule+0x29/0x70 [ 192.037988] [<ffffffff812e8d75>] fuse_request_send+0xe5/0x2c0 [ 192.037999] [<ffffffff8108d330>] ? __init_waitqueue_head+0x60/0x60 [ 192.038007] [<ffffffff812f167b>] fuse_send_write.isra.21+0xbb/0xd0 [ 192.038015] [<ffffffff812f2319>] fuse_perform_write+0x269/0x490 [ 192.038022] [<ffffffff812f283f>] fuse_file_aio_write+0x2ff/0x3b0 [ 192.038031] [<ffffffff811b9793>] do_sync_write+0xa3/0xe0 [ 192.038039] [<ffffffff811b9e43>] vfs_write+0xb3/0x180 [ 192.038045] [<ffffffff811ba182>] sys_write+0x52/0xa0 [ 192.038053] [<ffffffff81704219>] system_call_fastpath+0x16/0x1b [ 192.038059] [ 192.038062] Restarting tasks ... done. [ 192.039225] PM: Basic memory bitmaps freed Is this expected? I would hope that the filesystem sync would flush the write before userspace processes were frozen, so I expect the system to hibernate after any pending writes complete. After running `echo 3 > /proc/sys/vm/drop_caches`, time shows that the cp command completes after 16 seconds when the system isn't being hibernated. This is on 3.8-rc4, although I have also seen it on kernels since 3.6. Sarah Sharp -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
