f3b9aae162
The pair of helpers trace_recursive_lock() and trace_recursive_unlock() have been introduced recently to provide generic tracing recursion protection. They are used in a symetric way: - trace_recursive_lock() on buffer reserve - trace_recursive_unlock() on buffer commit However sometimes, we don't commit but discard on entry to the buffer, ie: in case of filter checking. Then we must also unlock the recursion protection on discard time, otherwise the tracing gets definitely deactivated and a warning is raised spuriously, such as: 111.119821] ------------[ cut here ]------------ [ 111.119829] WARNING: at kernel/trace/ring_buffer.c:1498 ring_buffer_lock_reserve+0x1b7/0x1d0() [ 111.119835] Hardware name: AMILO Li 2727 [ 111.119839] Modules linked in: [ 111.119846] Pid: 5731, comm: Xorg Tainted: G W 2.6.30-rc1 #69 [ 111.119851] Call Trace: [ 111.119863] [<ffffffff8025ce68>] warn_slowpath+0xd8/0x130 [ 111.119873] [<ffffffff8028a30f>] ? __lock_acquire+0x19f/0x1ae0 [ 111.119882] [<ffffffff8028a30f>] ? __lock_acquire+0x19f/0x1ae0 [ 111.119891] [<ffffffff802199b0>] ? native_sched_clock+0x20/0x70 [ 111.119899] [<ffffffff80286dee>] ? put_lock_stats+0xe/0x30 [ 111.119906] [<ffffffff80286eb8>] ? lock_release_holdtime+0xa8/0x150 [ 111.119913] [<ffffffff802c8ae7>] ring_buffer_lock_reserve+0x1b7/0x1d0 [ 111.119921] [<ffffffff802cd110>] trace_buffer_lock_reserve+0x30/0x70 [ 111.119930] [<ffffffff802ce000>] trace_current_buffer_lock_reserve+0x20/0x30 [ 111.119939] [<ffffffff802474e8>] ftrace_raw_event_sched_switch+0x58/0x100 [ 111.119948] [<ffffffff808103b7>] __schedule+0x3a7/0x4cd [ 111.119957] [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b [ 111.119964] [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b [ 111.119971] [<ffffffff80810c08>] schedule+0x18/0x40 [ 111.119977] [<ffffffff80810e09>] preempt_schedule+0x39/0x60 [ 111.119985] [<ffffffff80813bd3>] _read_unlock+0x53/0x60 [ 111.119993] [<ffffffff807259d2>] sock_def_readable+0x72/0x80 [ 111.120002] [<ffffffff807ad5ed>] unix_stream_sendmsg+0x24d/0x3d0 [ 111.120011] [<ffffffff807219a3>] sock_aio_write+0x143/0x160 [ 111.120019] [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b [ 111.120026] [<ffffffff80721860>] ? sock_aio_write+0x0/0x160 [ 111.120033] [<ffffffff80721860>] ? sock_aio_write+0x0/0x160 [ 111.120042] [<ffffffff8031c283>] do_sync_readv_writev+0xf3/0x140 [ 111.120049] [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b [ 111.120057] [<ffffffff80276ff0>] ? autoremove_wake_function+0x0/0x40 [ 111.120067] [<ffffffff8045d489>] ? cap_file_permission+0x9/0x10 [ 111.120074] [<ffffffff8045c1e6>] ? security_file_permission+0x16/0x20 [ 111.120082] [<ffffffff8031cab4>] do_readv_writev+0xd4/0x1f0 [ 111.120089] [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b [ 111.120097] [<ffffffff80211b56>] ? ftrace_call+0x5/0x2b [ 111.120105] [<ffffffff8031cc18>] vfs_writev+0x48/0x70 [ 111.120111] [<ffffffff8031cd65>] sys_writev+0x55/0xc0 [ 111.120119] [<ffffffff80211e32>] system_call_fastpath+0x16/0x1b [ 111.120125] ---[ end trace 15605f4e98d5ccb5 ]--- [ Impact: fix spurious warning triggering tracing shutdown ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> |
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.. | ||
blktrace.c | ||
ftrace.c | ||
Kconfig | ||
kmemtrace.c | ||
Makefile | ||
ring_buffer.c | ||
trace.c | ||
trace.h | ||
trace_boot.c | ||
trace_branch.c | ||
trace_clock.c | ||
trace_event_profile.c | ||
trace_event_types.h | ||
trace_events.c | ||
trace_events_filter.c | ||
trace_export.c | ||
trace_functions.c | ||
trace_functions_graph.c | ||
trace_hw_branches.c | ||
trace_irqsoff.c | ||
trace_mmiotrace.c | ||
trace_nop.c | ||
trace_output.c | ||
trace_output.h | ||
trace_power.c | ||
trace_printk.c | ||
trace_sched_switch.c | ||
trace_sched_wakeup.c | ||
trace_selftest.c | ||
trace_selftest_dynamic.c | ||
trace_stack.c | ||
trace_stat.c | ||
trace_stat.h | ||
trace_syscalls.c | ||
trace_sysprof.c | ||
trace_workqueue.c |