Messages in this thread Patch in this message | | | Date | Sun, 22 Jan 2006 02:22:33 +0900 | From | Tejun Heo <> | Subject | [PATCH] BLOCK: use disk_stat_add instead of __disk_stat_add in __end_that_request_first |
| |
Unlike end_that_request_last, caller is supposed to own the request when it calls __end_that_request_first and thus allowed to call from any context without any locking. When SCSI EH completes requests, it calls __end_that_request_first from kernel thread context without holding any lock and none of preemption/bh/irq disabled. This results in the following warning.
BUG: using smp_processor_id() in preemptible [00000001] code: scsi_eh_6/927 caller is __end_that_request_first+0xbf/0x500 [<c01046e3>] show_trace+0x13/0x20 [<c010470e>] dump_stack+0x1e/0x20 [<c02231c8>] debug_smp_processor_id+0xa8/0xb0 [<c021167f>] __end_that_request_first+0xbf/0x500 [<c0211ad1>] end_that_request_chunk+0x11/0x20 [<c03360b2>] scsi_end_request+0x32/0x110 -- snip --
This patch makes __end_that_request_first() use undashed disk_stat_add() which doesn't assume preemption is disabled.
Signed-off-by: Tejun Heo <htejun@gmail.com>
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 8e27d0a..eb0473b 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -3153,7 +3153,7 @@ static int __end_that_request_first(stru if (blk_fs_request(req) && req->rq_disk) { const int rw = rq_data_dir(req); - __disk_stat_add(req->rq_disk, sectors[rw], nr_bytes >> 9); + disk_stat_add(req->rq_disk, sectors[rw], nr_bytes >> 9); } total_bytes = bio_nbytes = 0; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |