Josef Bacik 4ce97dbf50 trace: Fix epoll hang when we race with new entries ... Epoll on trace_pipe can sometimes hang in a weird case. If the ring buffer is empty when we set waiters_pending but an event shows up exactly at that moment we can miss being woken up by the ring buffers irq work. Since ring_buffer_empty() is inherently racey we will sometimes think that the buffer is not empty. So we don't get woken up and we don't think there are any events even though there were some ready when we added the watch, which makes us hang. This patch fixes this by making sure that we are actually on the wait list before we set waiters_pending, and add a memory barrier to make sure ring_buffer_empty() is going to be correct. Link: http://lkml.kernel.org/p/1408989581-23727-1-git-send-email-jbacik@fb.com Cc: stable@vger.kernel.org # 3.10+ Cc: Martin Lau <kafai@fb.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>		2014-08-25 20:18:11 -04:00
..
blktrace.c	Most of the changes were largely clean ups, and some documentation.	2014-04-03 10:26:31 -07:00
ftrace.c	ftrace: Use current addr when converting to nop in __ftrace_replace_code()	2014-08-22 21:04:35 -04:00
Kconfig	tracing: Remove function_trace_stop and HAVE_FUNCTION_TRACE_MCOUNT_TEST	2014-07-18 13:58:12 -04:00
Makefile	tracing: Move the trace_seq_* functions into its own trace_seq.c file	2014-07-01 07:13:35 -04:00
power-traces.c	PM / tracing: remove deprecated power trace API	2013-01-26 00:39:12 +01:00
ring_buffer_benchmark.c	trace: Replace hardcoding of 19 with MAX_NICE	2014-02-27 12:41:03 +01:00
ring_buffer.c	trace: Fix epoll hang when we race with new entries	2014-08-25 20:18:11 -04:00
rpm-traces.c
trace_benchmark.c	tracing: Only calculate stats of tracepoint benchmarks for 2^32 times	2014-06-06 00:41:38 -04:00
trace_benchmark.h	tracing: Add tracepoint benchmark tracepoint	2014-05-29 22:49:54 -04:00
trace_branch.c	tracing: Update event filters for multibuffer	2013-11-05 16:50:20 -05:00
trace_clock.c	tracing: Fix wraparound problems in "uptime" trace clock	2014-07-21 09:56:12 -04:00
trace_entries.h	tracing: Add trace_puts() for even faster trace_printk() tracing	2013-03-15 00:35:55 -04:00
trace_event_perf.c	perf: Check permission only for parent tracepoint event	2014-07-28 10:01:38 +02:00
trace_events_filter_test.h
trace_events_filter.c	tracing: Kill "filter_string" arg of replace_preds()	2014-07-16 14:58:53 -04:00
trace_events_trigger.c	tracing: Use rcu_dereference_sched() for trace event triggers	2014-05-02 23:12:42 -04:00
trace_events.c	Oleg Nesterov did several clean ups with the tracing filter code.	2014-08-04 12:02:48 -07:00
trace_export.c	tracing: Fix anonymous unions in struct ftrace_event_call	2014-04-09 20:02:55 -04:00
trace_functions_graph.c	tracing: Convert local function_graph functions to static	2014-07-18 21:16:06 -04:00
trace_functions.c	tracing: Remove mock up poll wait function	2014-04-30 08:40:05 -04:00
trace_irqsoff.c	tracing: Allow irq/preempt tracers to be used by instances	2014-04-21 13:59:29 -04:00
trace_kdb.c	tracing: Consolidate max_tr into main trace_array structure	2013-03-15 00:35:40 -04:00
trace_kprobe.c	Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-06-12 19:18:49 -07:00
trace_mmiotrace.c	tracing: Update event filters for multibuffer	2013-11-05 16:50:20 -05:00
trace_nop.c	tracing: Remove mock up poll wait function	2014-04-30 08:40:05 -04:00
trace_output.c	tracing: Add trace_seq_buffer_ptr() helper function	2014-07-01 07:13:39 -04:00
trace_output.h	tracing: Make trace_seq_putmem_hex() more robust	2014-07-01 07:13:37 -04:00
trace_printk.c	tracing: Add __tracepoint_string() to export string pointers	2013-07-26 13:39:44 -04:00
trace_probe.c	kprobes, ftrace: Use NOKPROBE_SYMBOL macro in ftrace	2014-04-24 10:26:39 +02:00
trace_probe.h	kprobes, ftrace: Use NOKPROBE_SYMBOL macro in ftrace	2014-04-24 10:26:39 +02:00
trace_sched_switch.c	tracing: Update event filters for multibuffer	2013-11-05 16:50:20 -05:00
trace_sched_wakeup.c	tracing: Remove mock up poll wait function	2014-04-30 08:40:05 -04:00
trace_selftest_dynamic.c
trace_selftest.c	tracing: Add static to local functions	2014-04-21 14:00:46 -04:00
trace_seq.c	tracing: Remove trace_seq_reserve()	2014-07-01 07:13:37 -04:00
trace_stack.c	tracing: Print max callstack on stacktrace bug	2014-06-02 16:43:49 -04:00
trace_stat.c	trace/trace_stat: use rbtree postorder iteration helper instead of opencoding	2013-11-05 16:01:47 -05:00
trace_stat.h
trace_syscalls.c	tracing: Consolidate event trigger code	2014-01-09 21:20:07 -05:00
trace_uprobe.c	tracing/uprobes: Kill the dead TRACE_EVENT_FL_USE_CALL_FILTER logic	2014-07-16 14:25:19 -04:00
trace.c	Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-08-05 17:46:42 -07:00
trace.h	tracing: let user specify tracing_thresh after selecting function_graph	2014-07-18 15:48:52 -04:00