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Vaibhav Nagarnaik 83f365554e ring-buffer: Allow for rescheduling when removing pages
When reducing ring buffer size, pages are removed by scheduling a work
item on each CPU for the corresponding CPU ring buffer. After the pages
are removed from ring buffer linked list, the pages are free()d in a
tight loop. The loop does not give up CPU until all pages are removed.
In a worst case behavior, when lot of pages are to be freed, it can
cause system stall.

After the pages are removed from the list, the free() can happen while
the work is rescheduled. Call cond_resched() in the loop to prevent the
system hangup.

Link: http://lkml.kernel.org/r/20180907223129.71994-1-vnagarnaik@google.com

Cc: stable@vger.kernel.org
Fixes: 83f40318da ("ring-buffer: Make removal of ring buffer pages atomic")
Reported-by: Jason Behmer <jbehmer@google.com>
Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-09-17 18:15:11 -04:00
..
Kconfig Masami found an off by one bug in the code that keeps "notrace" functions 2018-08-23 13:07:00 -07:00
Makefile tracing: Allow gcov profiling on only ftrace subsystem 2018-08-21 09:11:49 -04:00
blktrace.c for-4.19/post-20180822 2018-08-22 13:38:05 -07:00
bpf_trace.c tracing: Add SPDX License format to bpf_trace.c 2018-08-16 19:07:36 -04:00
ftrace.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
power-traces.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
preemptirq_delay_test.c tracing: preemptirq_delay_run() can be static 2018-07-27 17:58:34 -04:00
ring_buffer.c ring-buffer: Allow for rescheduling when removing pages 2018-09-17 18:15:11 -04:00
ring_buffer_benchmark.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
rpm-traces.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace.c Updates for v4.19: 2018-08-20 18:32:00 -07:00
trace.h tracing: Fix SPDX format headers to use C++ style comments 2018-08-16 19:08:06 -04:00
trace_benchmark.c rcu: Rename cond_resched_rcu_qs() to cond_resched_tasks_rcu_qs() 2018-05-15 10:27:29 -07:00
trace_benchmark.h tracing: Fix SPDX format headers to use C++ style comments 2018-08-16 19:08:06 -04:00
trace_branch.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_clock.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
trace_entries.h tracing: Fix SPDX format headers to use C++ style comments 2018-08-16 19:08:06 -04:00
trace_event_perf.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
trace_events.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
trace_events_filter.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
trace_events_filter_test.h tracing: Fix SPDX format headers to use C++ style comments 2018-08-16 19:08:06 -04:00
trace_events_hist.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
trace_events_trigger.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
trace_export.c tracing: Add trigger file for trace_markers tracefs/ftrace/print 2018-05-29 08:28:53 -04:00
trace_functions.c tracing: Update stack trace skipping for ORC unwinder 2018-01-23 15:57:00 -05:00
trace_functions_graph.c tracing: Fix missing return symbol in function_graph output 2018-07-03 18:47:11 -04:00
trace_hwlat.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
trace_irqsoff.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
trace_kdb.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_kprobe.c Masami found an off by one bug in the code that keeps "notrace" functions 2018-08-23 13:07:00 -07:00
trace_kprobe_selftest.c selftest/ftrace: Move kprobe selftest function to separate compile unit 2018-07-30 18:41:04 -04:00
trace_kprobe_selftest.h tracing: Fix SPDX format headers to use C++ style comments 2018-08-16 19:08:06 -04:00
trace_mmiotrace.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_nop.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_output.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
trace_output.h tracing: Fix SPDX format headers to use C++ style comments 2018-08-16 19:08:06 -04:00
trace_preemptirq.c tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage" 2018-08-10 15:12:00 -04:00
trace_printk.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
trace_probe.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
trace_probe.h tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
trace_sched_switch.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_sched_wakeup.c Merge branch 'linus' into sched/core, to pick up fixes 2017-11-08 10:17:15 +01:00
trace_selftest.c Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
trace_selftest_dynamic.c ftrace: Mark function tracer test functions noinline/noclone 2018-01-23 15:57:29 -05:00
trace_seq.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
trace_stack.c tracing: Fix the file mode of stack tracer 2018-05-03 11:58:05 -04:00
trace_stat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_stat.h tracing: Fix SPDX format headers to use C++ style comments 2018-08-16 19:08:06 -04:00
trace_syscalls.c Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
trace_uprobe.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
tracing_map.c tracing: Add SPDX License format tags to tracing files 2018-08-16 19:08:06 -04:00
tracing_map.h tracing: Fix SPDX format headers to use C++ style comments 2018-08-16 19:08:06 -04:00