From: Carsten Otte the following patch in your broken-out series produces an incorrect warning on s390: dynticks-extend-next_timer_interrupt-to-use-a-reference-jiffie.patch I get plenty of those on my syslog with 2.6.19-rc2-mm1: Oct 18 17:13:19 t6360021 klogd: BUG: warning at kernel/timer.c:688/__next_timer_interrupt() Oct 18 17:13:19 t6360021 klogd: 0000000000103502 000000001ff8dc20 0000000000000002 0000000000000000 Oct 18 17:13:19 t6360021 klogd: 000000001ff8dcc0 000000001ff8dc38 000000001ff8dc38 0000000000103574 Oct 18 17:13:19 t6360021 klogd: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 Oct 18 17:13:19 t6360021 klogd: 000000001ff8dc20 000000000000000c 000000001ff8dc20 000000001ff8dc90 Oct 18 17:13:19 t6360021 klogd: 00000000004221e8 0000000000103574 000000001ff8dc20 000000001ff8dc70 Oct 18 17:13:19 t6360021 klogd: Call Trace: Oct 18 17:13:19 t6360021 klogd: ([<0000000000103502>] show_trace+0x166/0x16c) Oct 18 17:13:19 t6360021 klogd: [<00000000001035ce>] show_stack+0xc6/0xf8 Oct 18 17:13:19 t6360021 klogd: [<000000000010362e>] dump_stack+0x2e/0x3c Oct 18 17:13:19 t6360021 klogd: [<0000000000137104>] __next_timer_interrupt+0x13c/0x270 Oct 18 17:13:19 t6360021 klogd: [<00000000001372da>] next_timer_interrupt+0xa2/0x124 Oct 18 17:13:19 t6360021 klogd: [<0000000000105568>] nohz_idle_notify+0x17c/0x244 Oct 18 17:13:19 t6360021 klogd: [<000000000041ce4c>] notifier_call_chain+0x64/0x88 Oct 18 17:13:19 t6360021 klogd: [<000000000041ceb0>] atomic_notifier_call_chain+0x40/0x8c Oct 18 17:13:19 t6360021 klogd: [<0000000000105dde>] cpu_idle+0x82/0x1fc Oct 18 17:13:19 t6360021 klogd: [<0000000000110104>] start_secondary+0xb0/0xc4 Oct 18 17:13:19 t6360021 klogd: [<0000000000000000>] 0x0 Oct 18 17:13:19 t6360021 klogd: [<0000000000000000>] 0x0 Problem is, that the warning assumes that there are always pending timer events on a system when a CPU is going idle. But this is not true in general, the system may be waiting for an I/O interruption, or the CPU may wait for an interprocessor signal. The patch below removes the warning, please apply. Signed-off-by: Carsten Otte Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Andrew Morton --- kernel/timer.c | 1 - 1 files changed, 1 deletion(-) diff -puN kernel/timer.c~dynticks-extend-next_timer_interrupt-to-use-a-reference-jiffie-remove-incorrect-warning-in-kernel-timerc kernel/timer.c --- a/kernel/timer.c~dynticks-extend-next_timer_interrupt-to-use-a-reference-jiffie-remove-incorrect-warning-in-kernel-timerc +++ a/kernel/timer.c @@ -529,7 +529,6 @@ found: } } } - WARN_ON(!found); return expires; } _