more lockdep-RCU and RCU_FAST_NO_HZ fixes
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From: Ingo Molnar on 28 Feb 2010 04:00 * Paul E. McKenney <paulmck(a)linux.vnet.ibm.com> wrote: > Hello! > > This series (1) makes RCU_FAST_NO_HZ actually do the full number of > iterations specified instead of just one and (2) fixes an RCU lockdep > splat. Thanks, applied. This one is pretty stubborn, it still triggers: [ 0.000000] soft-irq read-recursion/321: ok | [ 0.000000] ------------------------------------------------------- [ 0.000000] Good, all 218 testcases passed! | [ 0.000000] --------------------------------- [ 0.000000] allocated 10485760 bytes of page_cgroup [ 0.000000] please try 'cgroup_disable=memory' option if you don't want memory cgroups [ 0.000000] [ 0.000000] =================================================== [ 0.000000] [ INFO: suspicious rcu_dereference_check() usage. ] [ 0.000000] --------------------------------------------------- [ 0.000000] kernel/sched_fair.c:3479 invoked rcu_dereference_check() without protection! [ 0.000000] [ 0.000000] other info that might help us debug this: [ 0.000000] [ 0.000000] no locks held by swapper/0. [ 0.000000] [ 0.000000] stack backtrace: [ 0.000000] Pid: 0, comm: swapper Not tainted 2.6.33-tip-01015-g97e7da3-dirty #10753 [ 0.000000] Call Trace: [ 0.000000] <IRQ> [<ffffffff8107f5d1>] lockdep_rcu_dereference+0xa1/0xb0 [ 0.000000] [<ffffffff8104afd1>] scheduler_tick+0x221/0x2c0 [ 0.000000] [<ffffffff8105f6d5>] update_process_times+0x55/0x70 [ 0.000000] [<ffffffff8107ac27>] tick_periodic+0x27/0x70 [ 0.000000] [<ffffffff8107ac8f>] tick_handle_periodic+0x1f/0x90 [ 0.000000] [<ffffffff8100e29a>] timer_interrupt+0x1a/0x30 [ 0.000000] [<ffffffff810a28aa>] handle_IRQ_event+0x3a/0xe0 [ 0.000000] [<ffffffff810a53ab>] handle_level_irq+0x8b/0x130 [ 0.000000] [<ffffffff8100da94>] handle_irq+0x44/0x70 [ 0.000000] [<ffffffff8100cfde>] do_IRQ+0x6e/0xf0 [ 0.000000] [<ffffffff817eea13>] ret_from_intr+0x0/0x16 [ 0.000000] <EOI> [<ffffffff8102dfe6>] ? native_restore_fl+0x6/0x10 [ 0.000000] [<ffffffff817ee3df>] _raw_spin_unlock_irqrestore+0x6f/0x80 [ 0.000000] [<ffffffff810a37f3>] __setup_irq+0x1b3/0x3b0 [ 0.000000] [<ffffffff810a3a18>] setup_irq+0x28/0x40 [ 0.000000] [<ffffffff81ef2914>] setup_default_timer_irq+0x12/0x14 [ 0.000000] [<ffffffff81ef292d>] hpet_time_init+0x17/0x19 [ 0.000000] [<ffffffff81ef28fb>] x86_late_time_init+0xa/0x11 [ 0.000000] [<ffffffff81eefcf4>] start_kernel+0x25f/0x2e6 [ 0.000000] [<ffffffff81eef30b>] x86_64_start_reservations+0xf6/0xfa [ 0.000000] [<ffffffff81eef409>] x86_64_start_kernel+0xfa/0x109 [ 0.000000] Fast TSC calibration using PIT [ 0.000000] Detected 2002.507 MHz processor. [ 0.004004] Calibrating delay loop (skipped), value calculated using timer frequency.. 4005.01 BogoMIPS (lpj=2002507) Ingo
From: Ingo Molnar on 1 Mar 2010 07:20 FYI, even with your patch applied i'm getting this in -tip testing: [ 0.000000] Memory: 914996k/1047744k available (15146k kernel code, 452k absent, 131584k reserved, 12516k data, 2552k init) [ 0.000000] SLUB: Genslabs=13, HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1 [ 0.000000] [ 0.000000] =================================================== [ 0.000000] [ INFO: suspicious rcu_dereference_check() usage. ] [ 0.000000] --------------------------------------------------- [ 0.000000] include/linux/cgroup.h:492 invoked rcu_dereference_check() without protection! [ 0.000000] [ 0.000000] other info that might help us debug this: [ 0.000000] [ 0.000000] 1 lock held by swapper/0: [ 0.000000] #0: (&rq->lock){......}, at: [<ffffffff81ec0bad>] init_idle+0x31/0x1ee [ 0.000000] [ 0.000000] stack backtrace: [ 0.000000] Pid: 0, comm: swapper Not tainted 2.6.33-tip+ #10563 [ 0.000000] Call Trace: [ 0.000000] [<ffffffff810ad1c1>] lockdep_rcu_dereference+0xa1/0xb0 [ 0.000000] [<ffffffff81ec0cbd>] init_idle+0x141/0x1ee [ 0.000000] [<ffffffff82ceff40>] sched_init+0x43a/0x4b6 [ 0.000000] [<ffffffff82cdcceb>] start_kernel+0x1b3/0x49e [ 0.000000] [<ffffffff82cdc319>] x86_64_start_reservations+0x120/0x124 [ 0.000000] [<ffffffff82cdc46b>] x86_64_start_kernel+0x14e/0x15d [ 0.000000] Hierarchical RCU implementation. [ 0.000000] RCU-based detection of stalled CPUs is enabled. [ 0.000000] NR_IRQS:4352 Config attached. The sha1 is: b5fabe1: Merge branch 'perf/urgent' i.e. your latest fix is included: 90a6501: sched, rcu: Fix rcu_dereference() for RCU-lockdep Thanks, Ingo
From: Peter Zijlstra on 1 Mar 2010 13:20
On Mon, 2010-03-01 at 08:08 -0800, Paul E. McKenney wrote: > On Mon, Mar 01, 2010 at 01:10:45PM +0100, Ingo Molnar wrote: > > > > FYI, even with your patch applied i'm getting this in -tip testing: > > > > [ 0.000000] Memory: 914996k/1047744k available (15146k kernel code, 452k absent, 131584k reserved, 12516k data, 2552k init) > > [ 0.000000] SLUB: Genslabs=13, HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1 > > [ 0.000000] > > [ 0.000000] =================================================== > > [ 0.000000] [ INFO: suspicious rcu_dereference_check() usage. ] > > [ 0.000000] --------------------------------------------------- > > [ 0.000000] include/linux/cgroup.h:492 invoked rcu_dereference_check() without protection! > > [ 0.000000] > > [ 0.000000] other info that might help us debug this: > > [ 0.000000] > > [ 0.000000] 1 lock held by swapper/0: > > [ 0.000000] #0: (&rq->lock){......}, at: [<ffffffff81ec0bad>] init_idle+0x31/0x1ee > > [ 0.000000] > > [ 0.000000] stack backtrace: > > [ 0.000000] Pid: 0, comm: swapper Not tainted 2.6.33-tip+ #10563 > > [ 0.000000] Call Trace: > > [ 0.000000] [<ffffffff810ad1c1>] lockdep_rcu_dereference+0xa1/0xb0 > > [ 0.000000] [<ffffffff81ec0cbd>] init_idle+0x141/0x1ee > > [ 0.000000] [<ffffffff82ceff40>] sched_init+0x43a/0x4b6 > > [ 0.000000] [<ffffffff82cdcceb>] start_kernel+0x1b3/0x49e > > [ 0.000000] [<ffffffff82cdc319>] x86_64_start_reservations+0x120/0x124 > > [ 0.000000] [<ffffffff82cdc46b>] x86_64_start_kernel+0x14e/0x15d > > [ 0.000000] Hierarchical RCU implementation. > > [ 0.000000] RCU-based detection of stalled CPUs is enabled. > > [ 0.000000] NR_IRQS:4352 > > > > Config attached. > > > > The sha1 is: > > > > b5fabe1: Merge branch 'perf/urgent' > > > > i.e. your latest fix is included: > > > > 90a6501: sched, rcu: Fix rcu_dereference() for RCU-lockdep > > Sigh! I clearly need a more organized approach for handling this very > early boot stuff. Fix is in progress, please accept my apologies for > the hassle! add: system_state != SYSTEM_RUNNING, to all the default rcu_read_lock*_held thingies? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |