Messages in this thread Patch in this message | | | From | Ming Lei <> | Subject | [PATCH] percpu: use raw_local_irq_* in _this_cpu op | Date | Mon, 13 Feb 2012 19:03:38 +0800 |
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It doesn't make sense to trace irq off or do irq flags lock proving inside 'this_cpu' operations, so replace local_irq_* with raw_local_irq_* in 'this_cpu' op.
Also the patch fixes one lockdep warning[1], which is caused by the added local_irq_save/restore(flags) in this_cpu_inc called by __debug_atomic_inc: kernel/lockdep.c
[1], [ 0.162841] ------------[ cut here ]------------ [ 0.167694] WARNING: at kernel/lockdep.c:3493 check_flags+0xc0/0x1d0() [ 0.174468] Modules linked in: [ 0.177703] Backtrace: [ 0.180328] [<c00171f0>] (dump_backtrace+0x0/0x110) from [<c0412320>] (dump_stack+0x18/0x1c) [ 0.189086] r6:c051f778 r5:00000da5 r4:00000000 r3:60000093 [ 0.195007] [<c0412308>] (dump_stack+0x0/0x1c) from [<c00410e8>] (warn_slowpath_common+0x54/0x6c) [ 0.204223] [<c0041094>] (warn_slowpath_common+0x0/0x6c) from [<c0041124>] (warn_slowpath_null+0x24/0x2c) [ 0.214111] r8:00000000 r7:00000000 r6:ee069598 r5:60000013 r4:ee082000 [ 0.220825] r3:00000009 [ 0.223693] [<c0041100>] (warn_slowpath_null+0x0/0x2c) from [<c0088f38>] (check_flags+0xc0/0x1d0) [ 0.232910] [<c0088e78>] (check_flags+0x0/0x1d0) from [<c008d348>] (lock_acquire+0x4c/0x11c) [ 0.241668] [<c008d2fc>] (lock_acquire+0x0/0x11c) from [<c0415aa4>] (_raw_spin_lock+0x3c/0x74) [ 0.250610] [<c0415a68>] (_raw_spin_lock+0x0/0x74) from [<c010a844>] (set_task_comm+0x20/0xc0) [ 0.259521] r6:ee069588 r5:ee0691c0 r4:ee082000 [ 0.264404] [<c010a824>] (set_task_comm+0x0/0xc0) from [<c0060780>] (kthreadd+0x28/0x108) [ 0.272857] r8:00000000 r7:00000013 r6:c0044a08 r5:ee0691c0 r4:ee082000 [ 0.279571] r3:ee083fe0 [ 0.282470] [<c0060758>] (kthreadd+0x0/0x108) from [<c0044a08>] (do_exit+0x0/0x6dc) [ 0.290405] r5:c0060758 r4:00000000 [ 0.294189] ---[ end trace 1b75b31a2719ed1c ]--- [ 0.299041] possible reason: unannotated irqs-on. [ 0.303955] irq event stamp: 5 [ 0.307159] hardirqs last enabled at (4): [<c001331c>] no_work_pending+0x8/0x2c [ 0.314880] hardirqs last disabled at (5): [<c0089b08>] trace_hardirqs_on_caller+0x60/0x26c [ 0.323547] softirqs last enabled at (0): [<c003f754>] copy_process+0x33c/0xef4 [ 0.331207] softirqs last disabled at (0): [< (null)>] (null) [ 0.337585] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
Signed-off-by: Ming Lei <tom.leiming@gmail.com> --- include/linux/percpu.h | 20 ++++++++++---------- 1 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 6e68d05..5ed1e38 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -294,9 +294,9 @@ do { \ #define _this_cpu_generic_to_op(pcp, val, op) \ do { \ unsigned long flags; \ - local_irq_save(flags); \ + raw_local_irq_save(flags); \ *__this_cpu_ptr(&(pcp)) op val; \ - local_irq_restore(flags); \ + raw_local_irq_restore(flags); \ } while (0) #ifndef this_cpu_write @@ -395,10 +395,10 @@ do { \ ({ \ typeof(pcp) ret__; \ unsigned long flags; \ - local_irq_save(flags); \ + raw_local_irq_save(flags); \ __this_cpu_add(pcp, val); \ ret__ = __this_cpu_read(pcp); \ - local_irq_restore(flags); \ + raw_local_irq_restore(flags); \ ret__; \ }) @@ -425,10 +425,10 @@ do { \ #define _this_cpu_generic_xchg(pcp, nval) \ ({ typeof(pcp) ret__; \ unsigned long flags; \ - local_irq_save(flags); \ + raw_local_irq_save(flags); \ ret__ = __this_cpu_read(pcp); \ __this_cpu_write(pcp, nval); \ - local_irq_restore(flags); \ + raw_local_irq_restore(flags); \ ret__; \ }) @@ -453,11 +453,11 @@ do { \ ({ \ typeof(pcp) ret__; \ unsigned long flags; \ - local_irq_save(flags); \ + raw_local_irq_save(flags); \ ret__ = __this_cpu_read(pcp); \ if (ret__ == (oval)) \ __this_cpu_write(pcp, nval); \ - local_irq_restore(flags); \ + raw_local_irq_restore(flags); \ ret__; \ }) @@ -490,10 +490,10 @@ do { \ ({ \ int ret__; \ unsigned long flags; \ - local_irq_save(flags); \ + raw_local_irq_save(flags); \ ret__ = __this_cpu_generic_cmpxchg_double(pcp1, pcp2, \ oval1, oval2, nval1, nval2); \ - local_irq_restore(flags); \ + raw_local_irq_restore(flags); \ ret__; \ }) -- 1.7.9
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