Ingo and All, -----Original Message----- From: Neil Zhang Sent: 2012年12月4日 17:31 To: Neil Zhang; pet...@infradead.org; mi...@kernel.org Cc: Chao Xie; linux-kernel@vger.kernel.org Subject: RE: [PATCH] sched/rt: don't enable runtime if already enabled
Hi All, -----Original Message----- From: Neil Zhang [mailto:zhan...@marvell.com] Sent: 2012年12月3日 16:01 To: mi...@redhat.com; pet...@infradead.org Cc: Chao Xie; linux-kernel@vger.kernel.org; Neil Zhang Subject: [PATCH] sched/rt: don't enable runtime if already enabled There are two paths will call __enable_runtime, they are enable_runtime and rq_online. Don't enable runtime again if it is already enabled. It can fix the following kernel BUG when do cpu hotplug while there are realtime threads running. [ 3347.091644] kernel BUG at kernel/sched/rt.c:687! [ 3347.091674] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM [ 3347.091674] Modules linked in: cidatattydev(O) gs_diag(O) diag(O) gs_modem(O) ccinetdev(O) cci_datastub(O) citty(O) msocke [ 3347.091705] CPU: 1 Tainted: G O (3.4.5+ #439) [ 3347.091735] PC is at __disable_runtime+0x1e4/0x240 [ 3347.091735] LR is at __disable_runtime+0x1dc/0x240 [ 3347.091735] pc : [<c0162124>] lr : [<c016211c>] psr: a0000093 [ 3347.091735] sp : e0061dc8 ip : c0807861 fp : c07a9740 [ 3347.091766] r10: c1a0b740 r9 : ffffffff r8 : fd050f80 [ 3347.091766] r7 : 00000002 r6 : 000003f8 r5 : c1a13740 r4 : c1a137d8 [ 3347.091766] r3 : ffffffff r2 : e0061dbc r1 : c06b11b6 r0 : 00000037 [ 3347.091796] Flags: NzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel [ 3347.091796] Control: 10c53c7d Table: 21e5004a DAC: 00000015 Signed-off-by: Neil Zhang <zhan...@marvell.com> --- kernel/sched/rt.c | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 418feb0..6525e5b 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -722,9 +722,11 @@ static void __enable_runtime(struct rq *rq) raw_spin_lock(&rt_b->rt_runtime_lock); raw_spin_lock(&rt_rq->rt_runtime_lock); - rt_rq->rt_runtime = rt_b->rt_runtime; - rt_rq->rt_time = 0; - rt_rq->rt_throttled = 0; + if (rt_rq->rt_runtime == RUNTIME_INF) { + rt_rq->rt_runtime = rt_b->rt_runtime; + rt_rq->rt_time = 0; + rt_rq->rt_throttled = 0; + } raw_spin_unlock(&rt_rq->rt_runtime_lock); raw_spin_unlock(&rt_b->rt_runtime_lock); } -- 1.7.4.1 Ingo seems use another mail now, update the To list. Best Regards, Neil Zhang Please help review it. Best Regards, Neil Zhang N�Р骒r��y����b�X�肚�v�^�)藓{.n�+�伐�{��赙zXФ�≤�}��财�z�&j:+v�����赙zZ+��+zf＂�h���~����i���z� �wア�?�ㄨ��&�)撷f��^j谦y�m��@A�a囤� 0鹅h���i
