* On Tue, May 10, 2011 at 10:29:57AM -0500, James Bottomley wrote: >On Tue, 2011-05-10 at 15:35 +0100, Mel Gorman wrote: >> On Tue, May 10, 2011 at 09:01:04AM -0500, James Bottomley wrote: >> > On Tue, 2011-05-10 at 11:21 +0100, Mel Gorman wrote: >> > > I really would like to hear if the fix makes a big difference or >> > > if we need to consider forcing SLUB high-order allocations bailing >> > > at the first sign of trouble (e.g. by masking out __GFP_WAIT in >> > > allocate_slab). Even with the fix applied, kswapd might be waking up >> > > less but processes will still be getting stalled in direct compaction >> > > and direct reclaim so it would still be jittery. >> > "the fix" being this >> > https://lkml.org/lkml/2011/3/5/121 >> Drop this for the moment. It was a long shot at best and there is little >> evidence the problem is in this area. >> I'm attaching two patches. The first is the NO_KSWAPD one to stop >> kswapd being woken up by SLUB using speculative high-orders. The second >> one is more drastic and prevents slub entering direct reclaim or >> compaction. It applies on top of patch 1. These are both untested and >> afraid are a bit rushed as well :( > >Preliminary results with both patches applied still show kswapd >periodically going up to 99% but it doesn't stay there, it comes back >down again (and, obviously, the system doesn't hang). > >This is sysrq-M from a couple of times when it went up there: > >[ 426.736958] SysRq : Show Memory >[ 426.736974] Mem-Info: >[ 426.736977] Node 0 DMA per-cpu: >[ 426.736983] CPU 0: hi: 0, btch: 1 usd: 0 >[ 426.736986] CPU 1: hi: 0, btch: 1 usd: 0 >[ 426.736989] CPU 2: hi: 0, btch: 1 usd: 0 >[ 426.736993] CPU 3: hi: 0, btch: 1 usd: 0 >[ 426.736996] Node 0 DMA32 per-cpu: >[ 426.737002] CPU 0: hi: 186, btch: 31 usd: 169 >[ 426.737005] CPU 1: hi: 186, btch: 31 usd: 40 >[ 426.737009] CPU 2: hi: 186, btch: 31 usd: 166 >[ 426.737012] CPU 3: hi: 186, btch: 31 usd: 168 >[ 426.737015] Node 0 Normal per-cpu: >[ 426.737020] CPU 0: hi: 0, btch: 1 usd: 0 >[ 426.737024] CPU 1: hi: 0, btch: 1 usd: 0 >[ 426.737027] CPU 2: hi: 0, btch: 1 usd: 0 >[ 426.737030] CPU 3: hi: 0, btch: 1 usd: 0 >[ 426.737036] active_anon:108658 inactive_anon:37031 isolated_anon:0 >[ 426.737037] active_file:32006 inactive_file:41051 isolated_file:32 >[ 426.737038] unevictable:8 dirty:41202 writeback:204 unstable:0 >[ 426.737039] free:191520 slab_reclaimable:8490 slab_unreclaimable:27477 >[ 426.737039] mapped:9176 shmem:26412 pagetables:5427 bounce:0 >[ 426.737051] Node 0 DMA free:8140kB min:548kB low:684kB high:820kB active_anon:0kB inactive_anon:12kB active_file:240kB inactive_file:7280kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15676kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:180kB slab_unreclaimable:16kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no >[ 426.737064] lowmem_reserve[]: 0 1856 1862 1862 >[ 426.737078] Node 0 DMA32 free:757892kB min:66820kB low:83524kB high:100228kB active_anon:434632kB inactive_anon:148112kB active_file:127784kB inactive_file:156924kB unevictable:32kB isolated(anon):0kB isolated(file):0kB present:1901408kB mlocked:32kB dirty:164808kB writeback:816kB mapped:36704kB shmem:105648kB slab_reclaimable:33676kB slab_unreclaimable:108372kB kernel_stack:2304kB pagetables:21708kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:160 all_unreclaimable? no >[ 426.737092] lowmem_reserve[]: 0 0 5 5 >[ 426.737106] Node 0 Normal free:48kB min:212kB low:264kB high:316kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:6060kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:104kB slab_unreclaimable:1520kB kernel_stack:176kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes >[ 426.737119] lowmem_reserve[]: 0 0 0 0 >[ 426.737132] Node 0 DMA: 3*4kB 2*8kB 1*16kB 1*32kB 2*64kB 2*128kB 2*256kB 2*512kB 2*1024kB 2*2048kB 0*4096kB = 8140kB >[ 426.737174] Node 0 DMA32: 945*4kB 585*8kB 6469*16kB 4871*32kB 3189*64kB 1338*128kB 228*256kB 58*512kB 24*1024kB 1*2048kB 0*4096kB = 757884kB >[ 426.737227] Node 0 Normal: 2*4kB 5*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 48kB >[ 426.737257] 99595 total pagecache pages >[ 426.737260] 0 pages in swap cache >[ 426.737263] Swap cache stats: add 0, delete 0, find 0/0 >[ 426.737266] Free swap = 3768316kB >[ 426.737268] Total swap = 3768316kB >[ 426.744603] 525808 pages RAM >[ 426.744612] 57618 pages reserved >[ 426.744614] 141551 pages shared >[ 426.744617] 186065 pages non-shared >[ 472.301810] SysRq : Show Memory >[ 472.301826] Mem-Info: >[ 472.301829] Node 0 DMA per-cpu: >[ 472.301835] CPU 0: hi: 0, btch: 1 usd: 0 >[ 472.301839] CPU 1: hi: 0, btch: 1 usd: 0 >[ 472.301842] CPU 2: hi: 0, btch: 1 usd: 0 >[ 472.301845] CPU 3: hi: 0, btch: 1 usd: 0 >[ 472.301848] Node 0 DMA32 per-cpu: >[ 472.301854] CPU 0: hi: 186, btch: 31 usd: 184 >[ 472.301857] CPU 1: hi: 186, btch: 31 usd: 46 >[ 472.301860] CPU 2: hi: 186, btch: 31 usd: 158 >[ 472.301863] CPU 3: hi: 186, btch: 31 usd: 163 >[ 472.301866] Node 0 Normal per-cpu: >[ 472.301871] CPU 0: hi: 0, btch: 1 usd: 0 >[ 472.301874] CPU 1: hi: 0, btch: 1 usd: 0 >[ 472.301878] CPU 2: hi: 0, btch: 1 usd: 0 >[ 472.301881] CPU 3: hi: 0, btch: 1 usd: 0 >[ 472.301886] active_anon:107673 inactive_anon:37031 isolated_anon:0 >[ 472.301887] active_file:31533 inactive_file:33323 isolated_file:32 >[ 472.301888] unevictable:8 dirty:26256 writeback:6475 unstable:0 >[ 472.301889] free:198742 slab_reclaimable:9347 slab_unreclaimable:28647 >[ 472.301889] mapped:8307 shmem:26412 pagetables:5427 bounce:0 >[ 472.301901] Node 0 DMA free:8140kB min:548kB low:684kB high:820kB active_anon:0kB inactive_anon:12kB active_file:240kB inactive_file:7280kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15676kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:180kB slab_unreclaimable:16kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no >[ 472.301915] lowmem_reserve[]: 0 1856 1862 1862 >[ 472.301928] Node 0 DMA32 free:786780kB min:66820kB low:83524kB high:100228kB active_anon:430692kB inactive_anon:148112kB active_file:125892kB inactive_file:126012kB unevictable:32kB isolated(anon):0kB isolated(file):128kB present:1901408kB mlocked:32kB dirty:105024kB writeback:25900kB mapped:33228kB shmem:105648kB slab_reclaimable:37104kB slab_unreclaimable:113052kB kernel_stack:2288kB pagetables:21708kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:3196 all_unreclaimable? no >[ 472.301943] lowmem_reserve[]: 0 0 5 5 >[ 472.301956] Node 0 Normal free:48kB min:212kB low:264kB high:316kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:6060kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:104kB slab_unreclaimable:1520kB kernel_stack:176kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes >[ 472.301968] lowmem_reserve[]: 0 0 0 0 >[ 472.301982] Node 0 DMA: 3*4kB 2*8kB 1*16kB 1*32kB 2*64kB 2*128kB 2*256kB 2*512kB 2*1024kB 2*2048kB 0*4096kB = 8140kB >[ 472.302015] Node 0 DMA32: 6121*4kB 1912*8kB 5094*16kB 4920*32kB 3168*64kB 1381*128kB 262*256kB 68*512kB 24*1024kB 1*2048kB 0*4096kB = 786756kB >[ 472.302048] Node 0 Normal: 2*4kB 5*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 48kB >[ 472.302090] 91312 total pagecache pages >[ 472.302093] 0 pages in swap cache >[ 472.302096] Swap cache stats: add 0, delete 0, find 0/0 >[ 472.302099] Free swap = 3768316kB >[ 472.302102] Total swap = 3768316kB >[ 472.309521] 525808 pages RAM >[ 472.309529] 57618 pages reserved >[ 472.309548] 142496 pages shared >[ 472.309551] 177182 pages non-shared > >I'll finish off this verification, and then re-run with the watch-highorder script running. > >James Hi, I saw similar lockups while doing a heavy copy routine (basically copying an entire partition). I don't think this may be related to ext4, since the source and destination filesystems were btrfs and xfs. =============================================================================================================== 9 00:04:58 localhost kernel: [39824.230679] INFO: task kswapd0:528 blocked for more than 120 seconds. May 9 00:04:58 localhost kernel: [39824.230684] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. May 9 00:04:58 localhost kernel: [39824.230690] kswapd0 D ffff8800bb90d740 0 528 2 0x00000000 May 9 00:04:58 localhost kernel: [39824.230699] ffff88013f6a3750 0000000000000046 0000000000000246 ffff88013b290040 May 9 00:04:58 localhost kernel: [39824.230708] ffff88013b290000 0000000000000001 ffff88013f6ea210 ffff88013f6a3fd8 May 9 00:04:58 localhost kernel: [39824.230716] ffff88013f6a3fd8 ffff88013f6a3fd8 0000000000000004 ffff88013f6ea470 May 9 00:04:58 localhost kernel: [39824.230724] Call Trace: May 9 00:04:58 localhost kernel: [39824.230738] [] io_schedule+0x73/0xc0 May 9 00:04:58 localhost kernel: [39824.230747] [] get_request_wait+0xdb/0x1e0 May 9 00:04:58 localhost kernel: [39824.230757] [] ? autoremove_wake_function+0x0/0x40 May 9 00:05:22 localhost kernel: [39824.230766] [] __make_request+0x76/0x560 May 9 00:05:22 localhost kernel: [39824.230774] [] ? account_page_writeback+0x28/0x30 May 9 00:05:22 localhost kernel: [39824.230782] [] generic_make_request+0x28e/0x560 May 9 00:05:22 localhost kernel: [39824.230790] [] submit_bio+0x85/0x110 May 9 00:05:22 localhost kernel: [39824.230797] [] ? bio_alloc_bioset+0xb2/0xf0 May 9 00:05:22 localhost kernel: [39824.230806] [] xfs_submit_ioend_bio.isra.11+0x57/0x80 May 9 00:05:22 localhost kernel: [39824.230816] [] xfs_submit_ioend+0xbb/0x110 May 9 00:05:22 localhost kernel: [39824.230818] [] xfs_vm_writepage+0x3f7/0x540 May 9 00:05:22 localhost kernel: [39824.230821] [] shrink_page_list+0x650/0x8f0 May 9 00:05:22 localhost kernel: [39824.230823] [] shrink_inactive_list+0x178/0x410 May 9 00:05:22 localhost kernel: [39824.230826] [] ? del_timer_sync+0x3a/0x60 May 9 00:05:22 localhost kernel: [39824.230828] [] shrink_zone+0x47e/0x540 May 9 00:05:22 localhost kernel: [39824.230831] [] ? shrink_slab+0x145/0x180 *May 9 00:05:22 localhost kernel: [39824.230833] [] kswapd+0x68d/0xa20 *May 9 00:05:22 localhost kernel: [39824.230835] [] ? kswapd+0x0/0xa20 May 9 00:05:22 localhost kernel: [39824.230837] [] kthread+0x8c/0xa0 May 9 00:05:22 localhost kernel: [39824.230841] [] ? schedule_tail+0x4c/0xf0 May 9 00:05:22 localhost kernel: [39824.230843] [] kernel_thread_helper+0x4/0x10 May 9 00:05:22 localhost kernel: [39824.230846] [] ? kthread+0x0/0xa0 May 9 00:05:22 localhost kernel: [39824.230848] [] ? kernel_thread_helper+0x0/0x10 May 9 00:05:22 localhost kernel: [39824.230853] INFO: task xfsbufd/sda9:3757 blocked for more than 120 seconds. May 9 00:05:22 localhost kernel: [39824.230854] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. May 9 00:05:22 localhost kernel: [39824.230856] xfsbufd/sda9 D ffff8800bb84d740 0 3757 2 0x00000000 May 9 00:05:22 localhost kernel: [39824.230858] ffff88013b12fb10 0000000000000046 0000000000000246 ffff88013f6736c0 May 9 00:05:22 localhost kernel: [39824.230861] ffff88013f673680 0000000000000001 ffff88013cec2210 ffff88013b12ffd8 May 9 00:05:22 localhost kernel: [39824.230863] ffff88013b12ffd8 ffff88013b12ffd8 0000000000000001 ffff88013cec2470 May 9 00:05:22 localhost kernel: [39824.230866] Call Trace: May 9 00:05:22 localhost kernel: [39824.230868] [] io_schedule+0x73/0xc0 May 9 00:05:22 localhost kernel: [39824.230870] [] get_request_wait+0xdb/0x1e0 May 9 00:05:22 localhost kernel: [39824.230873] [] ? autoremove_wake_function+0x0/0x40 May 9 00:05:22 localhost kernel: [39824.230875] [] __make_request+0x76/0x560 May 9 00:05:22 localhost kernel: [39824.230878] [] ? resched_best_mask.isra.60+0x114/0x130 May 9 00:05:22 localhost kernel: [39824.230880] [] generic_make_request+0x28e/0x560 May 9 00:05:22 localhost kernel: [39824.230883] [] ? update_cpu_clock+0x19c/0x3d0 May 9 00:05:22 localhost kernel: [39824.230885] [] submit_bio+0x85/0x110 May 9 00:05:22 localhost kernel: [39824.230887] [] ? bio_alloc_bioset+0x5a/0xf0 May 9 00:05:22 localhost kernel: [39824.230889] [] _xfs_buf_ioapply+0x19c/0x300 May 9 00:05:22 localhost kernel: [39824.230892] [] ? xfs_bdstrat_cb+0x5d/0x100 May 9 00:05:22 localhost kernel: [39824.230894] [] xfs_buf_iorequest+0x5e/0x140 May 9 00:05:22 localhost kernel: [39824.230896] [] xfs_bdstrat_cb+0x5d/0x100 May 9 00:05:22 localhost kernel: [39824.230899] [] xfsbufd+0x106/0x180 May 9 00:05:22 localhost kernel: [39824.230901] [] ? xfsbufd+0x0/0x180 May 9 00:05:22 localhost kernel: [39824.230903] [] kthread+0x8c/0xa0 May 9 00:05:22 localhost kernel: [39824.230905] [] ? schedule_tail+0x4c/0xf0 May 9 00:05:22 localhost kernel: [39824.230907] [] kernel_thread_helper+0x4/0x10 May 9 00:05:22 localhost kernel: [39824.230909] [] ? kthread+0x0/0xa0 May 9 00:05:22 localhost kernel: [39824.230911] [] ? kernel_thread_helper+0x0/0x10 May 9 00:05:22 localhost kernel: [39824.230913] INFO: task xfsbufd/sda11:3769 blocked for more than 120 seconds. May 9 00:05:22 localhost kernel: [39824.230914] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. May 9 00:05:22 localhost kernel: [39824.230915] xfsbufd/sda11 D ffff8800bb84d740 0 3769 2 0x00000000 May 9 00:05:22 localhost kernel: [39824.230918] ffff88013b183b10 0000000000000046 0000000000000246 ffff88013f6736c0 May 9 00:05:22 localhost kernel: [39824.230920] ffff88013f673680 0000000000000001 ffff88013b299b40 ffff88013b183fd8 May 9 00:05:22 localhost kernel: [39824.230923] ffff88013b183fd8 ffff88013b183fd8 0000000000000001 ffff88013b299da0 May 9 00:05:22 localhost kernel: [39824.230925] Call Trace: May 9 00:05:22 localhost kernel: [39824.230928] [] io_schedule+0x73/0xc0 May 9 00:05:22 localhost kernel: [39824.230930] [] get_request_wait+0xdb/0x1e0 May 9 00:05:22 localhost kernel: [39824.230932] [] ? autoremove_wake_function+0x0/0x40 May 9 00:05:22 localhost kernel: [39824.230935] [] __make_request+0x76/0x560 May 9 00:05:22 localhost kernel: [39824.230938] [] ? __sg_alloc_table+0x7f/0x140 May 9 00:05:22 localhost kernel: [39824.230941] [] generic_make_request+0x28e/0x560 May 9 00:05:22 localhost kernel: [39824.230943] [] ? update_cpu_clock+0x19c/0x3d0 May 9 00:05:22 localhost kernel: [39824.230946] [] ? ata_scsi_rw_xlat+0x0/0x210 May 9 00:05:22 localhost kernel: [39824.230948] [] submit_bio+0x85/0x110 May 9 00:05:22 localhost kernel: [39824.230950] [] ? bio_alloc_bioset+0x5a/0xf0 May 9 00:05:22 localhost kernel: [39824.230953] [] _xfs_buf_ioapply+0x19c/0x300 May 9 00:05:22 localhost kernel: [39824.230955] [] ? xfs_bdstrat_cb+0x5d/0x100 May 9 00:05:22 localhost kernel: [39824.230957] [] xfs_buf_iorequest+0x5e/0x140 May 9 00:05:22 localhost kernel: [39824.230959] [] xfs_bdstrat_cb+0x5d/0x100 May 9 00:05:22 localhost kernel: [39824.230962] [] xfsbufd+0x106/0x180 May 9 00:05:22 localhost kernel: [39824.230964] [] ? xfsbufd+0x0/0x180 May 9 00:05:22 localhost kernel: [39824.230966] [] kthread+0x8c/0xa0 May 9 00:05:22 localhost kernel: [39824.230968] [] ? schedule_tail+0x4c/0xf0 May 9 00:05:22 localhost kernel: [39824.230970] [] kernel_thread_helper+0x4/0x10 May 9 00:05:22 localhost kernel: [39824.230972] [] ? kthread+0x0/0xa0 May 9 00:05:22 localhost kernel: [39824.230974] [] ? kernel_thread_helper+0x0/0x10 May 9 00:05:22 localhost kernel: [39824.230989] INFO: task logrotate:1749 blocked for more than 120 seconds. May 9 00:05:22 localhost kernel: [39824.230990] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. May 9 00:05:22 localhost kernel: [39824.230992] logrotate D ffff8800bb90d740 0 1749 1748 0x00000000 May 9 00:05:22 localhost kernel: [39824.230994] ffff88000c6f3788 0000000000000082 ffff88000c6f3738 ffff88013f475890 May 9 00:05:22 localhost kernel: [39824.230997] 0000000000000001 0000000000000001 0000000000000001 ffff88000c6f3fd8 May 9 00:05:22 localhost kernel: [39824.230999] ffff88000c6f3fd8 ffff88000c6f3fd8 0000000000000004 ffff88013f475af0 May 9 00:05:22 localhost kernel: [39824.231002] Call Trace: May 9 00:05:22 localhost kernel: [39824.231004] [] io_schedule+0x73/0xc0 May 9 00:05:22 localhost kernel: [39824.231006] [] get_request_wait+0xdb/0x1e0 May 9 00:05:22 localhost kernel: [39824.231008] [] ? autoremove_wake_function+0x0/0x40 May 9 00:05:22 localhost kernel: [39824.231011] [] __make_request+0x76/0x560 May 9 00:05:22 localhost kernel: [39824.231014] [] ? __getblk+0x24/0x280 May 9 00:05:22 localhost kernel: [39824.231016] [] generic_make_request+0x28e/0x560 May 9 00:05:22 localhost kernel: [39824.231020] [] ? ext4_mark_iloc_dirty+0x39c/0x5a0 May 9 00:05:22 localhost kernel: [39824.231022] [] submit_bio+0x85/0x110 May 9 00:05:22 localhost kernel: [39824.231024] [] ? bio_alloc_bioset+0x5a/0xf0 May 9 00:05:22 localhost kernel: [39824.231027] [] submit_bh+0xeb/0x120 May 9 00:05:22 localhost kernel: [39824.231029] [] __block_write_full_page+0x210/0x390 May 9 00:05:22 localhost kernel: [39824.231031] [] ? wake_up_bit+0x2e/0x40 May 9 00:05:22 localhost kernel: [39824.231034] [] ? end_buffer_async_write+0x0/0x200 May 9 00:05:22 localhost kernel: [39824.231036] [] ? noalloc_get_block_write+0x0/0x30 May 9 00:05:22 localhost kernel: [39824.231038] [] ? end_buffer_async_write+0x0/0x200 May 9 00:05:22 localhost kernel: [39824.231041] [] block_write_full_page_endio+0xf5/0x140 May 9 00:05:22 localhost kernel: [39824.231043] [] ? noalloc_get_block_write+0x0/0x30 May 9 00:05:22 localhost kernel: [39824.231045] [] block_write_full_page+0x15/0x20 May 9 00:05:22 localhost kernel: [39824.231048] [] mpage_da_submit_io+0x451/0x510 May 9 00:05:22 localhost kernel: [39824.231050] [] ? ext4_mark_iloc_dirty+0x39c/0x5a0 May 9 00:05:22 localhost kernel: [39824.231053] [] ? ext4_mark_inode_dirty+0x82/0x230 May 9 00:05:22 localhost kernel: [39824.231055] [] mpage_da_map_and_submit+0x1d6/0x410 May 9 00:05:22 localhost kernel: [39824.231059] [] ? jbd2_journal_start+0x13/0x20 May 9 00:05:22 localhost kernel: [39824.231061] [] ext4_da_writepages+0x3e1/0x750 May 9 00:05:22 localhost kernel: [39824.231064] [] do_writepages+0x21/0x40 May 9 00:05:22 localhost kernel: [39824.231066] [] __filemap_fdatawrite_range+0x5b/0x60 May 9 00:05:22 localhost kernel: [39824.231068] [] filemap_flush+0x1c/0x20 May 9 00:05:22 localhost kernel: [39824.231070] [] ext4_alloc_da_blocks+0x4c/0xe0 May 9 00:05:22 localhost kernel: [39824.231073] [] ext4_release_file+0x79/0xc0 May 9 00:05:22 localhost kernel: [39824.231075] [] fput+0xda/0x200 May 9 00:05:22 localhost kernel: [39824.231077] [] filp_close+0x55/0x80 May 9 00:05:22 localhost kernel: [39824.231079] [] sys_close+0xb6/0x120 May 9 00:05:22 localhost kernel: [39824.231082] [] system_call_fastpath+0x16/0x1b =========================================================================================================================================================== The mv was basically frozen though after sometime it resumed. I also noticed that levels of dirty data were really high (=~ 1G) which I presumed may have caused this. The kernel is ======================================================== Linux Xye 2.6.39-rc6 #78 SMP PREEMPT Mon May 9 14:38:17 IST 2011 x86_64 Intel(R) Core(TM) i7 CPU Q 740 @ 1.73GHz GenuineIntel GNU/Linux ====================================================== Also, I am not using cgroups or systemd at the moment. Also, this is not a Fedora system. (Arch linux). This happened only once. After which it has been fine, though I have not done such high throughput copying after that. --------------------- Raghavendra D Prabhu