Messages in this thread | | | Subject | Re: [2.6.35-rc1 BUG]: Calling sched_clock causes stack trace with DEBUG_PREEMPT | From | Steven Rostedt <> | Date | Wed, 02 Jun 2010 22:25:09 -0400 |
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On Wed, 2010-06-02 at 18:13 +0530, David John wrote: > On 06/01/2010 03:53 PM, Jens Axboe wrote: > > On Tue, Jun 01 2010, David John wrote: > >> On 06/01/2010 12:15 PM, David John wrote: > >>> Hi, > >>> > >>> I get stack traces like the following: > >>> > >>> BUG: using smp_processor_id() in preemptible [00000000] code: init/1 > >>> caller is native_sched_clock+0x37/0x6d > >>> Pid: 1, comm: init Not tainted 2.6.35-rc1 #99 > >>> Call Trace: > >>> [<ffffffff811c422b>] debug_smp_processor_id+0xd3/0xec > >>> [<ffffffff81008a1e>] native_sched_clock+0x37/0x6d > >>> [<ffffffff811a7bfd>] blk_rq_init+0x92/0x9e > >>> [<ffffffff811a7f2e>] get_request+0x1c8/0x27e > >>> [<ffffffff811a8011>] get_request_wait+0x2d/0x13c > >>> [<ffffffff810306ee>] ? get_parent_ip+0x11/0x42 > >>> [<ffffffff81411ea6>] ? add_preempt_count+0xad/0xb1 > >>> [<ffffffff811a83b3>] __make_request+0x293/0x3b8 > >>> [<ffffffff81099737>] ? mempool_alloc_slab+0x10/0x12 > >>> [<ffffffff811a6bc4>] generic_make_request+0x187/0x1ea > >>> [<ffffffff810306ee>] ? get_parent_ip+0x11/0x42 > >>> [<ffffffff811a6ce5>] submit_bio+0xbe/0xc7 > >>> [<ffffffff810f1f37>] submit_bh+0xef/0x111 > >>> [<ffffffff810f4865>] block_read_full_page+0x1ec/0x20c > >>> [<ffffffff810f6815>] ? blkdev_get_block+0x0/0x5e > >>> [<ffffffff81411de6>] ? sub_preempt_count+0x92/0xa5 > >>> [<ffffffff810a0500>] ? __lru_cache_add+0x73/0x93 > >>> [<ffffffff810f6e81>] blkdev_readpage+0x13/0x15 > >>> [<ffffffff8109f981>] __do_page_cache_readahead+0x161/0x194 > >>> [<ffffffff8109f9d0>] ra_submit+0x1c/0x20 > >>> [<ffffffff8109fc5f>] ondemand_readahead+0x1bb/0x1ce > >>> [<ffffffff810973c9>] ? rcu_read_unlock+0xe/0x29 > >>> [<ffffffff8109fd46>] page_cache_sync_readahead+0x38/0x3a > >>> [<ffffffff810993c2>] generic_file_aio_read+0x24d/0x57f > >>> [<ffffffff810cf973>] ? __mem_cgroup_try_charge+0x78/0x46c > >>> [<ffffffff810d2aa0>] do_sync_read+0xc6/0x103 > >>> [<ffffffff810306ee>] ? get_parent_ip+0x11/0x42 > >>> [<ffffffff810adca5>] ? handle_mm_fault+0x7cb/0x7e5 > >>> [<ffffffff810f69c5>] ? block_ioctl+0x32/0x36 > >>> [<ffffffff81189fcc>] ? selinux_file_permission+0x57/0xae > >>> [<ffffffff81184524>] ? security_file_permission+0x11/0x13 > >>> [<ffffffff810d34af>] vfs_read+0xa6/0x103 > >>> [<ffffffff810d35c2>] sys_read+0x45/0x69 > >>> [<ffffffff810029ab>] system_call_fastpath+0x16/0x1b > >>> > >>> Since with commit 9195291e you call 'set_start_time_ns' from > >>> 'blk_rq_init' which in turn calls 'sched_clock' with preempt enabled. > >>> There are other calls to sched_clock in blk-cgroup.c. Maybe they should > >>> be checked as well? > >>> > >>> Regards, > >>> David. > >>> > >> > >> I see this has been reported. Never mind. > > > > This should fix it for now, if you have time to test, then that would > > not hurt. > > Yes, this works.
I had the same issue, and this patch fixed it for me too.
-- Steve
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