forked from Minki/linux
ff081e05bf
While running hotplug tests I ran into this RCU splat =============================== [ INFO: suspicious RCU usage. ] 3.4.0 #3275 Tainted: G W ------------------------------- include/linux/rcupdate.h:729 rcu_read_lock() used illegally while idle! other info that might help us debug this: RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 RCU used illegally from extended quiescent state! 4 locks held by swapper/2/0: #0: ((cpu_died).wait.lock){......}, at: [<c00ab128>] complete+0x1c/0x5c #1: (&p->pi_lock){-.-.-.}, at: [<c00b275c>] try_to_wake_up+0x2c/0x388 #2: (&rq->lock){-.-.-.}, at: [<c00b2860>] try_to_wake_up+0x130/0x388 #3: (rcu_read_lock){.+.+..}, at: [<c00abe5c>] cpuacct_charge+0x28/0x1f4 stack backtrace: [<c001521c>] (unwind_backtrace+0x0/0x12c) from [<c00abec8>] (cpuacct_charge+0x94/0x1f4) [<c00abec8>] (cpuacct_charge+0x94/0x1f4) from [<c00b395c>] (update_curr+0x24c/0x2c8) [<c00b395c>] (update_curr+0x24c/0x2c8) from [<c00b59c4>] (enqueue_task_fair+0x50/0x194) [<c00b59c4>] (enqueue_task_fair+0x50/0x194) from [<c00afea4>] (enqueue_task+0x30/0x34) [<c00afea4>] (enqueue_task+0x30/0x34) from [<c00b0908>] (ttwu_activate+0x14/0x38) [<c00b0908>] (ttwu_activate+0x14/0x38) from [<c00b28a8>] (try_to_wake_up+0x178/0x388) [<c00b28a8>] (try_to_wake_up+0x178/0x388) from [<c00a82a0>] (__wake_up_common+0x34/0x78) [<c00a82a0>] (__wake_up_common+0x34/0x78) from [<c00ab154>] (complete+0x48/0x5c) [<c00ab154>] (complete+0x48/0x5c) from [<c07db7cc>] (cpu_die+0x2c/0x58) [<c07db7cc>] (cpu_die+0x2c/0x58) from [<c000f954>] (cpu_idle+0x64/0xfc) [<c000f954>] (cpu_idle+0x64/0xfc) from [<80208160>] (0x80208160) When a cpu is marked offline during its idle thread it calls cpu_die() during an RCU idle period. cpu_die() calls complete() to notify the killing process that the cpu has died. complete() calls into the scheduler code and eventually grabs an RCU read lock in cpuacct_charge(). Mark complete() as RCU_NONIDLE so that RCU pays attention to this CPU for the duration of the complete() function even though it's in idle. Suggested-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> |
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| .. | ||
| boot | ||
| common | ||
| configs | ||
| include/asm | ||
| kernel | ||
| lib | ||
| mach-at91 | ||
| mach-bcmring | ||
| mach-clps711x | ||
| mach-cns3xxx | ||
| mach-davinci | ||
| mach-dove | ||
| mach-ebsa110 | ||
| mach-ep93xx | ||
| mach-exynos | ||
| mach-footbridge | ||
| mach-gemini | ||
| mach-h720x | ||
| mach-highbank | ||
| mach-imx | ||
| mach-integrator | ||
| mach-iop13xx | ||
| mach-iop32x | ||
| mach-iop33x | ||
| mach-ixp4xx | ||
| mach-kirkwood | ||
| mach-ks8695 | ||
| mach-l7200/include/mach | ||
| mach-lpc32xx | ||
| mach-mmp | ||
| mach-msm | ||
| mach-mv78xx0 | ||
| mach-mxs | ||
| mach-netx | ||
| mach-nomadik | ||
| mach-omap1 | ||
| mach-omap2 | ||
| mach-orion5x | ||
| mach-picoxcell | ||
| mach-pnx4008 | ||
| mach-prima2 | ||
| mach-pxa | ||
| mach-realview | ||
| mach-rpc | ||
| mach-s3c24xx | ||
| mach-s3c64xx | ||
| mach-s3c2410 | ||
| mach-s3c2412 | ||
| mach-s3c2440 | ||
| mach-s5p64x0 | ||
| mach-s5pc100 | ||
| mach-s5pv210 | ||
| mach-sa1100 | ||
| mach-shark | ||
| mach-shmobile | ||
| mach-spear3xx | ||
| mach-spear6xx | ||
| mach-spear13xx | ||
| mach-tegra | ||
| mach-u300 | ||
| mach-ux500 | ||
| mach-versatile | ||
| mach-vexpress | ||
| mach-vt8500 | ||
| mach-w90x900 | ||
| mach-zynq | ||
| mm | ||
| net | ||
| nwfpe | ||
| oprofile | ||
| plat-iop | ||
| plat-mxc | ||
| plat-nomadik | ||
| plat-omap | ||
| plat-orion | ||
| plat-pxa | ||
| plat-s3c24xx | ||
| plat-samsung | ||
| plat-spear | ||
| plat-versatile | ||
| tools | ||
| vfp | ||
| Kconfig | ||
| Kconfig-nommu | ||
| Kconfig.debug | ||
| Makefile | ||