Hi, I observe the below warnings while trying to boot Exynos5420 based boards since yesterday's linux-next (next-20140616) using multi_v7_defconfig. Looks like it is triggered by the commit 56e6921829 ("CPU hotplug, smp: flush any pending IPI callbacks before CPU offline"). Any ideas? ************************************************************* [ 0.046521] Exynos MCPM support installed [ 0.048939] CPU1: Booted secondary processor [ 0.065005] CPU1: update cpu_capacity 1535 [ 0.065011] CPU1: thread -1, cpu 1, socket 0, mpidr 80000001 [ 0.065660] CPU2: Booted secondary processor [ 0.085005] CPU2: update cpu_capacity 1535 [ 0.085012] CPU2: thread -1, cpu 2, socket 0, mpidr 80000002 [ 0.085662] CPU3: Booted secondary processor [ 0.105005] CPU3: update cpu_capacity 1535 [ 0.105011] CPU3: thread -1, cpu 3, socket 0, mpidr 80000003 [ 1.105031] CPU4: failed to come online [ 1.105081] ------------[ cut here ]------------ [ 1.105104] WARNING: CPU: 0 PID: 1 at kernel/smp.c:228 flush_smp_call_function_queue+0xc0/0x178() [ 1.105112] Modules linked in: [ 1.105129] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.15.0-next-20140616-00002-g38f9385a061b #2035 [ 1.105157] [<c02160f0>] (unwind_backtrace) from [<c0211c8c>] (show_stack+0x10/0x14) [ 1.105179] [<c0211c8c>] (show_stack) from [<c0853794>] (dump_stack+0x8c/0x9c) [ 1.105198] [<c0853794>] (dump_stack) from [<c024bdf4>] (warn_slowpath_common+0x70/0x8c) [ 1.105216] [<c024bdf4>] (warn_slowpath_common) from [<c024beac>] (warn_slowpath_null+0x1c/0x24) [ 1.105235] [<c024beac>] (warn_slowpath_null) from [<c02a3944>] (flush_smp_call_function_queue+0xc0/0x178) [ 1.105253] [<c02a3944>] (flush_smp_call_function_queue) from [<c02a3a94>] (hotplug_cfd+0x98/0xd8) [ 1.105269] [<c02a3a94>] (hotplug_cfd) from [<c026b064>] (notifier_call_chain+0x44/0x84) [ 1.105285] [<c026b064>] (notifier_call_chain) from [<c024c1a4>] (_cpu_up+0x120/0x170) [ 1.105302] [<c024c1a4>] (_cpu_up) from [<c024c264>] (cpu_up+0x70/0x94) [ 1.105319] [<c024c264>] (cpu_up) from [<c0b5839c>] (smp_init+0xac/0xb0) [ 1.105337] [<c0b5839c>] (smp_init) from [<c0b2fc54>] (kernel_init_freeable+0x90/0x1dc) [ 1.105353] [<c0b2fc54>] (kernel_init_freeable) from [<c0851248>] (kernel_init+0xc/0xe8) [ 1.105368] [<c0851248>] (kernel_init) from [<c020e7f8>] (ret_from_fork+0x14/0x3c) [ 1.105389] ---[ end trace bc66942e4ab63168 ]--- [ 2.105047] CPU5: failed to come online [ 2.105073] ------------[ cut here ]------------ [ 2.105091] WARNING: CPU: 0 PID: 1 at kernel/smp.c:228 flush_smp_call_function_queue+0xc0/0x178() [ 2.105099] Modules linked in: [ 2.105114] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 3.15.0-next-20140616-00002-g38f9385a061b #2035 [ 2.105135] [<c02160f0>] (unwind_backtrace) from [<c0211c8c>] (show_stack+0x10/0x14) [ 2.105153] [<c0211c8c>] (show_stack) from [<c0853794>] (dump_stack+0x8c/0x9c) [ 2.105170] [<c0853794>] (dump_stack) from [<c024bdf4>] (warn_slowpath_common+0x70/0x8c) [ 2.105187] [<c024bdf4>] (warn_slowpath_common) from [<c024beac>] (warn_slowpath_null+0x1c/0x24) [ 2.105205] [<c024beac>] (warn_slowpath_null) from [<c02a3944>] (flush_smp_call_function_queue+0xc0/0x178) [ 2.105222] [<c02a3944>] (flush_smp_call_function_queue) from [<c02a3a94>] (hotplug_cfd+0x98/0xd8) [ 2.105237] [<c02a3a94>] (hotplug_cfd) from [<c026b064>] (notifier_call_chain+0x44/0x84) [ 2.105252] [<c026b064>] (notifier_call_chain) from [<c024c1a4>] (_cpu_up+0x120/0x170) [ 2.105268] [<c024c1a4>] (_cpu_up) from [<c024c264>] (cpu_up+0x70/0x94) [ 2.105285] [<c024c264>] (cpu_up) from [<c0b5839c>] (smp_init+0xac/0xb0) [ 2.105301] [<c0b5839c>] (smp_init) from [<c0b2fc54>] (kernel_init_freeable+0x90/0x1dc) [ 2.105316] [<c0b2fc54>] (kernel_init_freeable) from [<c0851248>] (kernel_init+0xc/0xe8) [ 2.105330] [<c0851248>] (kernel_init) from [<c020e7f8>] (ret_from_fork+0x14/0x3c) [ 2.105339] ---[ end trace bc66942e4ab63169 ]--- [ 3.105064] CPU6: failed to come online [ 3.105089] ------------[ cut here ]------------ [ 3.105107] WARNING: CPU: 0 PID: 1 at kernel/smp.c:228 flush_smp_call_function_queue+0xc0/0x178() [ 3.105115] Modules linked in: [ 3.105131] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 3.15.0-next-20140616-00002-g38f9385a061b #2035 [ 3.105150] [<c02160f0>] (unwind_backtrace) from [<c0211c8c>] (show_stack+0x10/0x14) [ 3.105168] [<c0211c8c>] (show_stack) from [<c0853794>] (dump_stack+0x8c/0x9c) [ 3.105185] [<c0853794>] (dump_stack) from [<c024bdf4>] (warn_slowpath_common+0x70/0x8c) [ 3.105202] [<c024bdf4>] (warn_slowpath_common) from [<c024beac>] (warn_slowpath_null+0x1c/0x24) [ 3.105220] [<c024beac>] (warn_slowpath_null) from [<c02a3944>] (flush_smp_call_function_queue+0xc0/0x178) [ 3.105237] [<c02a3944>] (flush_smp_call_function_queue) from [<c02a3a94>] (hotplug_cfd+0x98/0xd8) [ 3.105252] [<c02a3a94>] (hotplug_cfd) from [<c026b064>] (notifier_call_chain+0x44/0x84) [ 3.105267] [<c026b064>] (notifier_call_chain) from [<c024c1a4>] (_cpu_up+0x120/0x170) [ 3.105283] [<c024c1a4>] (_cpu_up) from [<c024c264>] (cpu_up+0x70/0x94) [ 3.105299] [<c024c264>] (cpu_up) from [<c0b5839c>] (smp_init+0xac/0xb0) [ 3.105315] [<c0b5839c>] (smp_init) from [<c0b2fc54>] (kernel_init_freeable+0x90/0x1dc) [ 3.105330] [<c0b2fc54>] (kernel_init_freeable) from [<c0851248>] (kernel_init+0xc/0xe8) [ 3.105344] [<c0851248>] (kernel_init) from [<c020e7f8>] (ret_from_fork+0x14/0x3c) [ 3.105353] ---[ end trace bc66942e4ab6316a ]--- [ 4.105081] CPU7: failed to come online [ 4.105106] ------------[ cut here ]------------ [ 4.105124] WARNING: CPU: 0 PID: 1 at kernel/smp.c:228 flush_smp_call_function_queue+0xc0/0x178() [ 4.105132] Modules linked in: [ 4.105147] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 3.15.0-next-20140616-00002-g38f9385a061b #2035 [ 4.105167] [<c02160f0>] (unwind_backtrace) from [<c0211c8c>] (show_stack+0x10/0x14) [ 4.105184] [<c0211c8c>] (show_stack) from [<c0853794>] (dump_stack+0x8c/0x9c) [ 4.105201] [<c0853794>] (dump_stack) from [<c024bdf4>] (warn_slowpath_common+0x70/0x8c) [ 4.105218] [<c024bdf4>] (warn_slowpath_common) from [<c024beac>] (warn_slowpath_null+0x1c/0x24) [ 4.105236] [<c024beac>] (warn_slowpath_null) from [<c02a3944>] (flush_smp_call_function_queue+0xc0/0x178) [ 4.105253] [<c02a3944>] (flush_smp_call_function_queue) from [<c02a3a94>] (hotplug_cfd+0x98/0xd8) [ 4.105268] [<c02a3a94>] (hotplug_cfd) from [<c026b064>] (notifier_call_chain+0x44/0x84) [ 4.105283] [<c026b064>] (notifier_call_chain) from [<c024c1a4>] (_cpu_up+0x120/0x170) [ 4.105299] [<c024c1a4>] (_cpu_up) from [<c024c264>] (cpu_up+0x70/0x94) [ 4.105315] [<c024c264>] (cpu_up) from [<c0b5839c>] (smp_init+0xac/0xb0) [ 4.105331] [<c0b5839c>] (smp_init) from [<c0b2fc54>] (kernel_init_freeable+0x90/0x1dc) [ 4.105346] [<c0b2fc54>] (kernel_init_freeable) from [<c0851248>] (kernel_init+0xc/0xe8) [ 4.105360] [<c0851248>] (kernel_init) from [<c020e7f8>] (ret_from_fork+0x14/0x3c) [ 4.105370] ---[ end trace bc66942e4ab6316b ]--- [ 4.105380] Brought up 4 CPUs Regards, Sachin -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html