Hi [ INFO: possible circular locking dependency detected ] 2.6.27-rc6-00034-gd1c6d2e #3 ------------------------------------------------------- nfsd/1766 is trying to acquire lock: (iprune_mutex){--..}, at: [<c01743fb>] shrink_icache_memory+0x38/0x1a8 but task is already holding lock: (&(&ip->i_iolock)->mr_lock){----}, at: [<c021134f>] xfs_ilock+0xa2/0xd6 I read files through nfs and saw delay for few seconds. System is x86_32, nfs, xfs. The last working kernel is 2.6.27-rc5, I do not know yet is it reproducible or not. the existing dependency chain (in reverse order) is: -> #1 (&(&ip->i_iolock)->mr_lock){----}: [<c0137b3f>] __lock_acquire+0x970/0xae8 [<c0137d12>] lock_acquire+0x5b/0x77 [<c012e803>] down_write_nested+0x35/0x6c [<c0211328>] xfs_ilock+0x7b/0xd6 [<c02114a1>] xfs_ireclaim+0x1d/0x59 [<c022e056>] xfs_finish_reclaim+0x12a/0x134 [<c022e1d8>] xfs_reclaim+0xbc/0x125 [<c023aba9>] xfs_fs_clear_inode+0x55/0x8e [<c01742aa>] clear_inode+0x7a/0xc9 [<c0174335>] dispose_list+0x3c/0xca [<c017453e>] shrink_icache_memory+0x17b/0x1a8 [<c014e5be>] shrink_slab+0xd3/0x12e [<c014e8e4>] kswapd+0x2cb/0x3ac [<c012b404>] kthread+0x39/0x5e [<c0103933>] kernel_thread_helper+0x7/0x10 [<ffffffff>] 0xffffffff -> #0 (iprune_mutex){--..}: [<c0137a14>] __lock_acquire+0x845/0xae8 [<c0137d12>] lock_acquire+0x5b/0x77 [<c037a03e>] __mutex_lock_common+0xa0/0x2d0 [<c037a2f7>] mutex_lock_nested+0x29/0x31 [<c01743fb>] shrink_icache_memory+0x38/0x1a8 [<c014e5be>] shrink_slab+0xd3/0x12e [<c014eded>] try_to_free_pages+0x1cf/0x287 [<c014a665>] __alloc_pages_internal+0x257/0x3c6 [<c014be50>] __do_page_cache_readahead+0xb7/0x16f [<c014c141>] ondemand_readahead+0x115/0x123 [<c014c1c6>] page_cache_sync_readahead+0x16/0x1c [<c017e7be>] __generic_file_splice_read+0xe0/0x3f7 [<c017eb3b>] generic_file_splice_read+0x66/0x80 [<c023914c>] xfs_splice_read+0x46/0x71 [<c0236573>] xfs_file_splice_read+0x24/0x29 [<c017d686>] do_splice_to+0x4e/0x5f [<c017da41>] splice_direct_to_actor+0xc1/0x185 [<c01d0e19>] nfsd_vfs_read+0x21d/0x310 [<c01d1387>] nfsd_read+0x84/0x9b [<c01d63e5>] nfsd3_proc_read+0xb9/0x104 [<c01cd1b7>] nfsd_dispatch+0xcf/0x1a2 [<c035f6d6>] svc_process+0x379/0x587 [<c01cd6db>] nfsd+0x106/0x153 [<c012b404>] kthread+0x39/0x5e [<c0103933>] kernel_thread_helper+0x7/0x10 [<ffffffff>] 0xffffffff other info that might help us debug this: 3 locks held by nfsd/1766: #0: (hash_sem){..--}, at: [<c01d3fbf>] exp_readlock+0xd/0xf #1: (&(&ip->i_iolock)->mr_lock){----}, at: [<c021134f>] xfs_ilock+0xa2/0xd6 #2: (shrinker_rwsem){----}, at: [<c014e50f>] shrink_slab+0x24/0x12e stack backtrace: Pid: 1766, comm: nfsd Not tainted 2.6.27-rc6-00034-gd1c6d2e #3 [<c03793b5>] ? printk+0xf/0x12 [<c0136fb8>] print_circular_bug_tail+0x5c/0x67 [<c0137a14>] __lock_acquire+0x845/0xae8 [<c0137d12>] lock_acquire+0x5b/0x77 [<c01743fb>] ? shrink_icache_memory+0x38/0x1a8 [<c037a03e>] __mutex_lock_common+0xa0/0x2d0 [<c01743fb>] ? shrink_icache_memory+0x38/0x1a8 [<c037a2f7>] mutex_lock_nested+0x29/0x31 [<c01743fb>] ? shrink_icache_memory+0x38/0x1a8 [<c01743fb>] shrink_icache_memory+0x38/0x1a8 [<c012e7c4>] ? down_read_trylock+0x38/0x42 [<c014e5be>] shrink_slab+0xd3/0x12e [<c014eded>] try_to_free_pages+0x1cf/0x287 [<c014d53f>] ? isolate_pages_global+0x0/0x3e [<c014a665>] __alloc_pages_internal+0x257/0x3c6 [<c0136bff>] ? trace_hardirqs_on_caller+0xe6/0x10d [<c014be50>] __do_page_cache_readahead+0xb7/0x16f [<c014c141>] ondemand_readahead+0x115/0x123 [<c014c1c6>] page_cache_sync_readahead+0x16/0x1c [<c017e7be>] __generic_file_splice_read+0xe0/0x3f7 [<c0135a86>] ? register_lock_class+0x17/0x26a [<c0137ca8>] ? __lock_acquire+0xad9/0xae8 [<c0135a86>] ? register_lock_class+0x17/0x26a [<c0137ca8>] ? __lock_acquire+0xad9/0xae8 [<c017d896>] ? spd_release_page+0x0/0xf [<c017eb3b>] generic_file_splice_read+0x66/0x80 [<c023914c>] xfs_splice_read+0x46/0x71 [<c0236573>] xfs_file_splice_read+0x24/0x29 [<c017d686>] do_splice_to+0x4e/0x5f [<c017da41>] splice_direct_to_actor+0xc1/0x185 [<c01d0f3c>] ? nfsd_direct_splice_actor+0x0/0xf [<c01d0e19>] nfsd_vfs_read+0x21d/0x310 [<c01d1387>] nfsd_read+0x84/0x9b [<c01d63e5>] nfsd3_proc_read+0xb9/0x104 [<c01cd1b7>] nfsd_dispatch+0xcf/0x1a2 [<c035f6d6>] svc_process+0x379/0x587 [<c01cd6db>] nfsd+0x106/0x153 [<c01cd5d5>] ? nfsd+0x0/0x153 [<c012b404>] kthread+0x39/0x5e [<c012b3cb>] ? kthread+0x0/0x5e [<c0103933>] kernel_thread_helper+0x7/0x10 ======================= e1000: eth0: e1000_clean_tx_irq: Detected Tx Unit Hang Tx Queue <0> TDH <86> TDT <86> next_to_use <86> next_to_clean <dc> buffer_info[next_to_clean] time_stamp <1f7dc5> next_to_watch <dc> jiffies <1f8034> next_to_watch.status <1> -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html