23 Aug, 2016
1 commit
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A few rcuperf dmesg output messages have no space between the flag and
the start of the message. In contrast, every other messages consistently
supplies a single space. This difference makes rcuperf dmesg output
hard to read and to mechanically parse. This commit therefore fixes
this problem by modifying a pr_alert() call and PERFOUT_STRING() macro
function to provide that single space.Signed-off-by: SeongJae Park
Signed-off-by: Paul E. McKenney
15 Jun, 2016
3 commits
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Fix to return a negative error code -ENOMEM from kcalloc() error
handling case instead of 0, as done elsewhere in this function.Signed-off-by: Wei Yongjun
Signed-off-by: Paul E. McKenney -
0day found a boot warning triggered in rcu_perf_writer() on !SMP kernel:
WARN_ON(rcu_gp_is_normal() && gp_exp);
, the root cause of which is trying to measure expedited grace
periods(by setting gp_exp to true by default) when all the grace periods
are normal(TINY RCU only has normal grace periods).However, such a mis-setting would only result in failing to measure the
performance for a specific kind of grace periods, therefore using a
WARN_ON to check this is a little overkilling. We could handle this
inside rcuperf module via some error messages to tell users about the
mis-settings.Therefore this patch removes the WARN_ON in rcu_perf_writer() and
handles those checkings in rcu_perf_init() with plain if() code.Moreover, this patch changes the default value of gp_exp to 1) align
with rcutorture tests and 2) make the default setting work for all RCU
implementations by default.Suggested-by: Paul E. McKenney
Signed-off-by: Boqun Feng
Fixes: http://lkml.kernel.org/r/57411b10.mFvG0+AgcrMXGtcj%fengguang.wu@intel.com
Signed-off-by: Paul E. McKenney -
This commit applies the infamous IS_ENABLED() macro to eliminate a #ifdef.
It also eliminates the RCU_PERF_TEST_RUNNABLE Kconfig option in favor
of the already-existing rcuperf.perf_runnable kernel boot parameter.Signed-off-by: Paul E. McKenney
01 Apr, 2016
7 commits
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After finishing its tests rcuperf tries to wake up shutdown_wq even if
"shutdown" param is set to false, resulting in a wake_up() call on an
unitialized wait_queue_head_t which leads to "BUG: spinlock bad magic" and
"BUG: unable to handle kernel NULL pointer dereference".Fix by checking "shutdown" param before waking up the queue.
Signed-off-by: Artem Savkov
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Running rcuperf can result in RCU CPU stall warnings and RT throttling.
These occur because on of the real-time writer processes does
ftrace_dump() while still running at real-time priority. This commit
therefore prevents these problems by setting the writer thread back to
SCHED_NORMAL (AKA SCHED_OTHER) before doing ftrace_dump().In addition, this commit adds a small fixed delay before dumping ftrace
buffer in order to decrease the probability that this dumping will
interfere with other writers' grace periods.Signed-off-by: Paul E. McKenney
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Boot-time activity can legitimately grab CPUs for extended time periods,
so the commit adds a boot parameter to delay the start of the performance
test until boot has completed. Defaults to 10 seconds.Signed-off-by: Paul E. McKenney
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This commit enables ftrace in the rcuperf TREE kernel build and adds
an ftrace_dump() at the end of rcuperf processing. This data will be
used to measure the actual durations of the expedited grace periods
without the added delays inherent in the kernel-module measurements.Signed-off-by: Paul E. McKenney
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This commit forces more deterministic update-side behavior by setting
rcuperf's rcu_perf_writer() kthreads to real-time priority.Signed-off-by: Paul E. McKenney
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This commit forces more deterministic behavior by binding rcuperf's
rcu_perf_reader() and rcu_perf_writer() kthreads to their respective
CPUs.Signed-off-by: Paul E. McKenney
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This commit adds a new rcuperf module that carries out simple performance
tests of RCU grace periods.Signed-off-by: Paul E. McKenney
