Return-path: Received: from mx2.mail.elte.hu ([157.181.151.9]:56002 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753188Ab0FKIzu (ORCPT ); Fri, 11 Jun 2010 04:55:50 -0400 Date: Fri, 11 Jun 2010 10:55:20 +0200 From: Ingo Molnar To: Jens Axboe Cc: Linus Torvalds , "Rafael J. Wysocki" , Carl Worth , Eric Anholt , Venkatesh Pallipadi , Dave Airlie , Jesse Barnes , David H?rdeman , Mauro Carvalho Chehab , Eric Dumazet , Linux Kernel Mailing List , Maciej Rutecki , Andrew Morton , Kernel Testers List , Network Development , Linux ACPI , Linux PM List , Linux SCSI List , Linux Wireless List , DRI Subject: Re: 2.6.35-rc2-git2: Reported regressions from 2.6.34 Message-ID: <20100611085520.GA20218@elte.hu> References:

<4C0F4872.7090909@fusionio.com> <20100611083249.GA11143@elte.hu> <4C11F661.3070604@fusionio.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <4C11F661.3070604@fusionio.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: * Jens Axboe wrote: > On 2010-06-11 10:32, Ingo Molnar wrote: > > > > * Jens Axboe wrote: > > > >> On 2010-06-09 03:53, Linus Torvalds wrote: > >>>> Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=16129 > >>>> Subject : BUG: using smp_processor_id() in preemptible [00000000] code: jbd2/sda2 > >>>> Submitter : Jan Kreuzer > >>>> Date : 2010-06-05 06:15 (4 days old) > >>> > >>> This seems to have been introduced by > >>> > >>> commit 7cbaef9c83e58bbd4bdd534b09052b6c5ec457d5 > >>> Author: Ingo Molnar > >>> Date: Sat Nov 8 17:05:38 2008 +0100 > >>> > >>> sched: optimize sched_clock() a bit > >>> > >>> sched_clock() uses cycles_2_ns() needlessly - which is an irq-disabling > >>> variant of __cycles_2_ns(). > >>> > >>> Most of the time sched_clock() is called with irqs disabled already. > >>> The few places that call it with irqs enabled need to be updated. > >>> > >>> Signed-off-by: Ingo Molnar > >>> > >>> and this seems to be one of those calling cases that need to be updated.. > >>> > >>> Ingo? The call trace is: > >>> > >>> BUG: using smp_processor_id() in preemptible [00000000] code: jbd2/sda2-8/337 > >>> caller is native_sched_clock+0x3c/0x68 > >>> Pid: 337, comm: jbd2/sda2-8 Not tainted 2.6.35-rc1jan+ #4 > >>> Call Trace: > >>> [] debug_smp_processor_id+0xc9/0xe4 > >>> [] native_sched_clock+0x3c/0x68 > >>> [] sched_clock+0x9/0xd > >>> [] blk_rq_init+0x97/0xa3 > >>> [] get_request+0x1c4/0x2d0 > >>> [] get_request_wait+0x29/0x1a6 > >>> [] __make_request+0x338/0x45b > >>> [] generic_make_request+0x2bb/0x330 > >>> [] submit_bio+0xd2/0xef > >>> [] submit_bh+0xf4/0x116 > >>> [] block_write_full_page_endio+0x89/0x96 > >>> [] block_write_full_page+0x15/0x17 > >>> [] ext4_writepage+0x356/0x36b > >>> [] __writepage+0x1a/0x39 > >>> [] write_cache_pages+0x20d/0x346 > >>> [] generic_writepages+0x27/0x29 > >>> [] journal_submit_data_buffers+0x110/0x17d > >>> [] jbd2_journal_commit_transaction+0x4cb/0x156d > >>> [] kjournald2+0x147/0x37a > >>> > >>> (from the bugzilla thing) > >> > >> This should be fixed by commit 28f4197e which was merged on friday. > > > > Hm, it's still not entirely fixed, as of 2.6.35-rc2-00131-g7908a9e. With some > > configs i get bad spinlock warnings during bootup: > > > > [ 28.968013] initcall net_olddevs_init+0x0/0x82 returned 0 after 93750 usecs > > [ 28.972003] calling b44_init+0x0/0x55 @ 1 > > [ 28.976009] bus: 'pci': add driver b44 > > [ 28.976374] sda: > > [ 28.978157] BUG: spinlock bad magic on CPU#1, async/0/117 > > [ 28.980000] lock: 7e1c5bbc, .magic: 00000000, .owner: /-1, .owner_cpu: 0 > > [ 28.980000] Pid: 117, comm: async/0 Not tainted 2.6.35-rc2-tip-01092-g010e7ef-dirty #8183 > > [ 28.980000] Call Trace: > > [ 28.980000] [<41ba6d55>] ? printk+0x20/0x24 > > [ 28.980000] [<4134b7b7>] spin_bug+0x7c/0x87 > > [ 28.980000] [<4134b853>] do_raw_spin_lock+0x1e/0x123 > > [ 28.980000] [<41ba92ca>] ? _raw_spin_lock_irqsave+0x12/0x20 > > [ 28.980000] [<41ba92d2>] _raw_spin_lock_irqsave+0x1a/0x20 > > [ 28.980000] [<4133476f>] blkiocg_update_io_add_stats+0x25/0xfb > > [ 28.980000] [<41335dae>] ? cfq_prio_tree_add+0xb1/0xc1 > > [ 28.980000] [<41337bc7>] cfq_insert_request+0x8c/0x425 > > [ 28.980000] [<41ba9271>] ? _raw_spin_unlock_irqrestore+0x17/0x23 > > [ 28.980000] [<41ba9271>] ? _raw_spin_unlock_irqrestore+0x17/0x23 > > [ 28.980000] [<41329225>] elv_insert+0x107/0x1a0 > > [ 28.980000] [<41329354>] __elv_add_request+0x96/0x9d > > [ 28.980000] [<4132bb8c>] ? drive_stat_acct+0x9d/0xc6 > > [ 28.980000] [<4132dd64>] __make_request+0x335/0x376 > > [ 28.980000] [<4132c726>] generic_make_request+0x336/0x39d > > [ 28.980000] [<410ad422>] ? kmem_cache_alloc+0xa1/0x105 > > [ 28.980000] [<41089285>] ? mempool_alloc_slab+0xe/0x10 > > [ 28.980000] [<41089285>] ? mempool_alloc_slab+0xe/0x10 > > [ 28.980000] [<41089285>] ? mempool_alloc_slab+0xe/0x10 > > [ 28.980000] [<41089347>] ? mempool_alloc+0x57/0xe2 > > [ 28.980000] [<4132c804>] submit_bio+0x77/0x8f > > [ 28.980000] [<410d2cbc>] ? bio_alloc_bioset+0x37/0x94 > > [ 28.980000] [<410ceb90>] submit_bh+0xc3/0xe2 > > [ 28.980000] [<410d1474>] block_read_full_page+0x249/0x259 > > [ 28.980000] [<410d31fb>] ? blkdev_get_block+0x0/0xc6 > > [ 28.980000] [<41087bfa>] ? add_to_page_cache_locked+0x94/0xb5 > > [ 28.980000] [<410d3d92>] blkdev_readpage+0xf/0x11 > > [ 28.980000] [<41088823>] do_read_cache_page+0x7d/0x11a > > [ 28.980000] [<410d3d83>] ? blkdev_readpage+0x0/0x11 > > [ 28.980000] [<410888f4>] read_cache_page_async+0x16/0x1b > > [ 28.980000] [<41088904>] read_cache_page+0xb/0x12 > > [ 28.980000] [<410e80e1>] read_dev_sector+0x2a/0x63 > > [ 28.980000] [<410e92e8>] adfspart_check_ICS+0x2e/0x166 > > [ 28.980000] [<41ba6d55>] ? printk+0x20/0x24 > > [ 28.980000] [<410e8d23>] rescan_partitions+0x196/0x3e4 > > [ 28.980000] [<41ba7dc7>] ? __mutex_unlock_slowpath+0x98/0x9f > > [ 28.980000] [<410e92ba>] ? adfspart_check_ICS+0x0/0x166 > > [ 28.980000] [<410d4277>] __blkdev_get+0x1e7/0x292 > > [ 28.980000] [<4133a201>] ? kobject_put+0x14/0x16 > > [ 28.980000] [<410d432c>] blkdev_get+0xa/0xc > > [ 28.980000] [<410e81fb>] register_disk+0x94/0xe5 > > [ 28.980000] [<413326c6>] ? blk_register_region+0x1b/0x20 > > [ 28.980000] [<41332815>] add_disk+0x57/0x95 > > [ 28.980000] [<41331fc6>] ? exact_match+0x0/0x8 > > [ 28.980000] [<4133233f>] ? exact_lock+0x0/0x11 > > [ 28.980000] [<41643848>] sd_probe_async+0x108/0x1be > > [ 28.980000] [<41048865>] async_thread+0xf5/0x1e6 > > [ 28.980000] [<4102cbcb>] ? default_wake_function+0x0/0xd > > [ 28.980000] [<41048770>] ? async_thread+0x0/0x1e6 > > [ 28.980000] [<410433df>] kthread+0x5f/0x64 > > [ 28.980000] [<41043380>] ? kthread+0x0/0x64 > > [ 28.980000] [<41002cc6>] kernel_thread_helper+0x6/0x10 > > [ 29.264071] async/1 used greatest stack depth: 2336 bytes left > > [ 29.267020] bus: 'ssb': add driver b44 > > [ 29.267072] initcall b44_init+0x0/0x55 returned 0 after 281250 usecs > > [ 29.267076] calling init_nic+0x0/0x16 @ 1 > > > > Caused by the same blkiocg_update_io_add_stats() function. Bootlog and config > > attached. Reproducible on that sha1 and with that config. > > I think I see it, the internal CFQ blkg groups are not properly > initialized... Will send a patch shortly. Cool - can test it with a short turnaround, the bug is easy to reproduce. Thanks, Ingo