On Mon, Nov 3, 2014 at 2:28 PM, Kirill Tkhai <tk...@yandex.ru> wrote: > Hi, > > the fix is already in PeterZ queue, it will go to mainline soon.
When is soon? We're still carrying: "sched: Remove lockdep check in sched_move_task()" from you as a stand alone patch on top of Linus' tree in Fedora. I would have thought this would be in 3.18-rc4 already. josh > > 03.11.2014, 17:54, "Fengguang Wu" <fengguang...@intel.com>: >> Greetings, >> >> 0day kernel testing robot got the below dmesg and the first bad commit is >> >> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master >> commit eeb61e53ea19be0c4015b00b2e8b3b2185436f2b >> Author: Kirill Tkhai <ktk...@parallels.com> >> AuthorDate: Mon Oct 27 14:18:25 2014 +0400 >> Commit: Ingo Molnar <mi...@kernel.org> >> CommitDate: Tue Oct 28 10:45:59 2014 +0100 >> >> sched: Fix race between task_group and sched_task_group >> >> The race may happen when somebody is changing task_group of a forking >> task. >> Child's cgroup is the same as parent's after dup_task_struct() (there >> just >> memory copying). Also, cfs_rq and rt_rq are the same as parent's. >> >> But if parent changes its task_group before it's called >> cgroup_post_fork(), >> we do not reflect this situation on child. Child's cfs_rq and rt_rq >> remain >> the same, while child's task_group changes in cgroup_post_fork(). >> >> To fix this we introduce fork() method, which calls sched_move_task() >> directly. >> This function changes sched_task_group on appropriate (also its logic has >> no problem with freshly created tasks, so we shouldn't introduce >> something >> special; we are able just to use it). >> >> Possibly, this decides the Burke Libbey's problem: >> https://lkml.org/lkml/2014/10/24/456 >> >> Signed-off-by: Kirill Tkhai <ktk...@parallels.com> >> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> >> Cc: Linus Torvalds <torva...@linux-foundation.org> >> Link: http://lkml.kernel.org/r/1414405105.19914.169.camel@tkhai >> Signed-off-by: Ingo Molnar <mi...@kernel.org> >> >> +------------------------------------------------+-----------+------------+---------------+ >> | | v3.18-rc2 | eeb61e53ea | >> next-20141031 | >> +------------------------------------------------+-----------+------------+---------------+ >> | boot_successes | 60 | 0 | >> 0 | >> | boot_failures | 0 | 20 | >> 11 | >> | INFO:suspicious_RCU_usage | 0 | 20 | >> 11 | >> | backtrace:do_fork | 0 | 20 | >> 11 | >> | WARNING:at_kernel/sched/core.c:__might_sleep() | 0 | 0 | >> 11 | >> | backtrace:rfcomm_run | 0 | 0 | >> 11 | >> | WARNING:CPU:#PID:#at/kbuild/src/smo | 0 | 0 | >> 1 | >> | BUG:kernel_boot_hang | 0 | 0 | >> 1 | >> +------------------------------------------------+-----------+------------+---------------+ >> >> [ 0.086529] debug: unmapping init [mem >> 0xffffffff82607000-0xffffffff82609fff] >> [ 0.090115] >> [ 0.090782] =============================== >> [ 0.091842] [ INFO: suspicious RCU usage. ] >> [ 0.092000] 3.18.0-rc2-00001-geeb61e5 #7 Not tainted >> [ 0.092000] ------------------------------- >> [ 0.092000] kernel/sched/core.c:7408 suspicious rcu_dereference_check() >> usage! >> [ 0.092000] >> [ 0.092000] other info that might help us debug this: >> [ 0.092000] >> [ 0.092000] >> [ 0.092000] rcu_scheduler_active = 1, debug_locks = 0 >> [ 0.092000] 2 locks held by swapper/0/0: >> [ 0.092000] #0: (&p->pi_lock){......}, at: [<ffffffff810b8d96>] >> task_rq_lock+0x30/0xaa >> [ 0.092000] #1: (&rq->lock){-.....}, at: [<ffffffff810b8db8>] >> task_rq_lock+0x52/0xaa >> [ 0.092000] >> [ 0.092000] stack backtrace: >> [ 0.092000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted >> 3.18.0-rc2-00001-geeb61e5 #7 >> [ 0.092000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 >> [ 0.092000] 0000000000000001 ffffffff819dbcb8 ffffffff815e2acd >> 000000000000182c >> [ 0.092000] ffffffff819f85c0 ffffffff819dbce8 ffffffff810d1774 >> ffff880013510000 >> [ 0.092000] ffff8800139de180 ffff880013528000 0000000000800300 >> ffffffff819dbd48 >> [ 0.092000] Call Trace: >> [ 0.092000] [<ffffffff815e2acd>] dump_stack+0x4e/0x68 >> [ 0.092000] [<ffffffff810d1774>] lockdep_rcu_suspicious+0x107/0x110 >> [ 0.092000] [<ffffffff810bf887>] sched_move_task+0xda/0x17b >> [ 0.092000] [<ffffffff810bf945>] cpu_cgroup_fork+0x9/0xb >> [ 0.092000] [<ffffffff8110c301>] cgroup_post_fork+0x9b/0xaa >> [ 0.092000] [<ffffffff8109c1bd>] copy_process+0x17e5/0x1832 >> [ 0.092000] [<ffffffff815def62>] ? rest_init+0x136/0x136 >> [ 0.092000] [<ffffffff8109c367>] do_fork+0x8a/0x243 >> [ 0.092000] [<ffffffff8109c541>] kernel_thread+0x21/0x23 >> [ 0.092000] [<ffffffff815dee4a>] rest_init+0x1e/0x136 >> [ 0.092000] [<ffffffff82520fb5>] start_kernel+0x4ba/0x4c7 >> [ 0.092000] [<ffffffff82520120>] ? early_idt_handlers+0x120/0x120 >> [ 0.092000] [<ffffffff825204de>] x86_64_start_reservations+0x2a/0x2c >> [ 0.092000] [<ffffffff825205e6>] x86_64_start_kernel+0x106/0x115 >> [ 0.096042] Getting VERSION: 1050014 >> [ 0.097061] Getting VERSION: 1050014 >> [ 0.098000] Getting ID: 0 >> >> git bisect start 4fbe40970dc154aaeeda0584aab8913fc073127b >> cac7f2429872d3733dc3f9915857b1691da2eb2f -- >> git bisect good fd2e6bbbe5b2e8f6d8ea6a28b614ec5c1c8b5a62 # 23:14 20+ >> 0 Merge remote-tracking branch 'hwmon-staging/hwmon-next' >> git bisect good ab6af24617af5f94df5185611f1eb39432d49292 # 01:33 20+ >> 0 Merge remote-tracking branch 'spi/for-next' >> git bisect bad f5ef810eb87c283118797ea33778c5b3c937ad29 # 02:08 0- >> 3 Merge remote-tracking branch 'staging/staging-next' >> git bisect bad 50247251e8b6078b491b5fb54dc31c24867f5930 # 02:47 0- >> 9 Merge remote-tracking branch 'rcu/rcu/next' >> git bisect bad 6a91cd724c20352f8cdc2a73c0649bae71897ed8 # 03:27 0- >> 7 Merge remote-tracking branch 'edac-amd/for-next' >> git bisect bad d7a8d245f2ffb9adde1a7121e5ab86eed8d03584 # 03:39 0- >> 4 Merge remote-tracking branch 'tip/auto-latest' >> git bisect good 26c2d2b39128adba276d140eefa2745591b88536 # 09:46 20+ >> 0 i386/audit: stop scribbling on the stack frame >> git bisect bad 3427445afd26bd2395f29241319283a93f362cd0 # 11:03 0- >> 1 sched: Exclude cond_resched() from nested sleep test >> git bisect bad 1a43a14a5bd9c32dbd7af35e35a5afa703944bcb # 11:39 0- >> 2 sched: Fix schedule_tail() to disable preemption >> git bisect bad f3a7e1a9c464a32ee186ab91388313c82e7ce018 # 12:38 0- >> 1 sched/dl: Fix preemption checks >> git bisect bad 1effd9f19324efb05fccc7421530e11a52db0278 # 12:55 0- >> 1 sched/numa: Fix unsafe get_task_struct() in task_numa_assign() >> git bisect bad 64be6f1f5f710f5995d41caf8a1767fe6d2b5a87 # 15:30 0- >> 3 sched/deadline: Don't replenish from a !SCHED_DEADLINE entity >> git bisect bad eeb61e53ea19be0c4015b00b2e8b3b2185436f2b # 17:18 0- >> 1 sched: Fix race between task_group and sched_task_group >> # first bad commit: [eeb61e53ea19be0c4015b00b2e8b3b2185436f2b] sched: Fix >> race between task_group and sched_task_group >> git bisect good cac7f2429872d3733dc3f9915857b1691da2eb2f # 17:31 60+ >> 0 Linux 3.18-rc2 >> git bisect bad 4fbe40970dc154aaeeda0584aab8913fc073127b # 17:31 0- >> 11 Add linux-next specific files for 20141031 >> git bisect bad 0df1f2487d2f0d04703f142813d53615d62a1da4 # 20:17 0- >> 3 Linux 3.18-rc3 >> git bisect bad a641d0e16b552f986e8c4a8735e66a1443a769cf # 21:44 0- >> 3 Add linux-next specific files for 20141103 >> >> This script may reproduce the error. >> >> ---------------------------------------------------------------------------- >> #!/bin/bash >> >> kernel=$1 >> initrd=yocto-minimal-x86_64.cgz >> >> wget --no-clobber >> https://github.com/fengguang/reproduce-kernel-bug/raw/master/initrd/$initrd >> >> kvm=( >> qemu-system-x86_64 >> -enable-kvm >> -cpu Haswell,+smep,+smap >> -kernel $kernel >> -initrd $initrd >> -m 320 >> -smp 1 >> -net nic,vlan=1,model=e1000 >> -net user,vlan=1 >> -boot order=nc >> -no-reboot >> -watchdog i6300esb >> -rtc base=localtime >> -serial stdio >> -display none >> -monitor null >> ) >> >> append=( >> hung_task_panic=1 >> earlyprintk=ttyS0,115200 >> debug >> apic=debug >> sysrq_always_enabled >> rcupdate.rcu_cpu_stall_timeout=100 >> panic=-1 >> softlockup_panic=1 >> nmi_watchdog=panic >> oops=panic >> load_ramdisk=2 >> prompt_ramdisk=0 >> console=ttyS0,115200 >> console=tty0 >> vga=normal >> root=/dev/ram0 >> rw >> drbd.minor_count=8 >> ) >> >> "${kvm[@]}" --append "${append[*]}" >> ---------------------------------------------------------------------------- >> >> Thanks, >> Fengguang >> , >> >> _______________________________________________ >> LKP mailing list >> l...@linux.intel.com > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
