Re: [OOPS] 2.6.21-rc6-git5 in cfq_dispatch_insert

From: Brad Campbell
Date: Wed Apr 25 2007 - 06:06:31 EST


Neil Brown wrote:


You could test this theory by putting a
WARN_ON(cfqq->next_rq == NULL);
at the end of cfq_reposition_rq_rb, just after the cfq_add_rq_rb call.



[ 756.311074] BUG: at block/cfq-iosched.c:543 cfq_reposition_rq_rb()
[ 756.329615] [<c0204fa1>] cfq_merged_request+0x71/0x80
[ 756.345046] [<c0204f30>] cfq_merged_request+0x0/0x80
[ 756.360216] [<c01fb4ae>] elv_merged_request+0x4e/0x50
[ 756.375647] [<c01ff1a7>] __make_request+0x1a7/0x2f0
[ 756.390557] [<c01ff497>] generic_make_request+0x127/0x190
[ 756.407025] [<c02bb011>] chunk_aligned_read+0x111/0x1c0
[ 756.422974] [<c01ff497>] generic_make_request+0x127/0x190
[ 756.439443] [<c02bb448>] make_request+0x388/0x3b0
[ 756.453834] [<c016e027>] __bio_add_page+0x147/0x1c0
[ 756.468742] [<c016dbff>] bio_alloc_bioset+0x7f/0x150
[ 756.483913] [<c02bac50>] raid5_mergeable_bvec+0x0/0x90
[ 756.499604] [<c016e107>] bio_add_page+0x37/0x50
[ 756.513473] [<c01ff497>] generic_make_request+0x127/0x190
[ 756.529943] [<c013586a>] mempool_free+0x2a/0x60
[ 756.543812] [<c016dadd>] bio_free+0x1d/0x40
[ 756.556645] [<c01ff546>] submit_bio+0x46/0xc0
[ 756.571389] [<c020a396>] radix_tree_node_alloc+0x16/0x60
[ 756.587610] [<c020a5c2>] radix_tree_insert+0xe2/0x130
[ 756.603039] [<c0139575>] __pagevec_lru_add+0x75/0x80
[ 756.618207] [<c0171971>] mpage_bio_submit+0x11/0x20
[ 756.633117] [<c01720e0>] mpage_readpages+0x100/0x140
[ 756.648287] [<c0187d50>] ext3_get_block+0x0/0xe0
[ 756.662419] [<c026fc0b>] scsi_end_request+0x9b/0xc0
[ 756.677329] [<c026dd2b>] scsi_delete_timer+0xb/0x20
[ 756.692240] [<c0188ae0>] ext3_readpages+0x0/0x20
[ 756.706369] [<c0138ac1>] read_pages+0xd1/0xe0
[ 756.719719] [<c0187d50>] ext3_get_block+0x0/0xe0
[ 756.733853] [<c0136e24>] __alloc_pages+0x54/0x2d0
[ 756.748242] [<c02704ff>] scsi_softirq_done+0x6f/0xe0
[ 756.763413] [<c02861a1>] sil_interrupt+0x81/0x90
[ 756.777544] [<c01ffa78>] blk_done_softirq+0x58/0x70
[ 756.792454] [<c0138b78>] __do_page_cache_readahead+0xa8/0x110
[ 756.809961] [<c0138d21>] blockable_page_cache_readahead+0x51/0xd0
[ 756.828508] [<c0138e14>] make_ahead_window+0x74/0xc0
[ 756.843679] [<c0138efa>] page_cache_readahead+0x9a/0x180
[ 756.859886] [<c0133704>] file_read_actor+0xc4/0xd0
[ 756.874537] [<c0133637>] do_generic_mapping_read+0x467/0x470
[ 756.891786] [<c0133893>] generic_file_aio_read+0x183/0x1c0
[ 756.908514] [<c0133640>] file_read_actor+0x0/0xd0
[ 756.922903] [<c026fb20>] scsi_next_command+0x30/0x50
[ 756.938073] [<c014e250>] do_sync_read+0xc0/0x100
[ 756.952204] [<c0124120>] autoremove_wake_function+0x0/0x50
[ 756.968934] [<c026bf00>] scsi_finish_command+0x40/0x60
[ 756.984622] [<c03319a5>] schedule+0x2e5/0x590
[ 756.997972] [<c014e316>] vfs_read+0x86/0x110
[ 757.011065] [<c014e5f7>] sys_read+0x47/0x80
[ 757.023897] [<c0102894>] syscall_call+0x7/0xb
[ 757.037250] =======================


I know this is late given a fix has been issued, but just got this in the logs with no other debug info at all. This kernel has *all* Jens debugging patches + the snippet from Neil above.

I'll apply the fix now and run it for a couple of days.

Brad
--
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