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| author | Joel Fernandes (Google) <joel@joelfernandes.org> | 2020-05-25 06:36:48 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-06-29 21:00:44 +0200 |
| commit | 653ed64b01dc5989f8f579d0038e987476c2c023 (patch) | |
| tree | 9443b9537680091b02267a99a0e4cb1a667cda2a /kernel/rcu/Makefile | |
| parent | rcuperf: Remove useless while loops around wait_event (diff) | |
| download | linux-653ed64b01dc5989f8f579d0038e987476c2c023.tar.xz linux-653ed64b01dc5989f8f579d0038e987476c2c023.zip | |
refperf: Add a test to measure performance of read-side synchronization
Add a test for comparing the performance of RCU with various read-side
synchronization mechanisms. The test has proved useful for collecting
data and performing these comparisons.
Currently RCU, SRCU, reader-writer lock, reader-writer semaphore and
reference counting can be measured using refperf.perf_type parameter.
Each invocation of the test runs measures performance of a specific
mechanism.
The maximum number of CPUs to concurrently run readers on is chosen by
the test itself and is 75% of the total number of CPUs. So if you had 24
CPUs, the test runs with a maximum of 18 parallel readers.
A number of experiments are conducted, and in each experiment, the
number of readers is increased by 1, upto the 75% of CPUs mark. During
each experiment, all readers execute an empty loop with refperf.loops
iterations and time the total loop duration. This is then averaged.
Example output:
Parameters "refperf.perf_type=srcu refperf.loops=2000000" looks like:
[ 3.347133] srcu-ref-perf:
[ 3.347133] Threads Time(ns)
[ 3.347133] 1 36
[ 3.347133] 2 34
[ 3.347133] 3 34
[ 3.347133] 4 34
[ 3.347133] 5 33
[ 3.347133] 6 33
[ 3.347133] 7 33
[ 3.347133] 8 33
[ 3.347133] 9 33
[ 3.347133] 10 33
[ 3.347133] 11 33
[ 3.347133] 12 33
[ 3.347133] 13 33
[ 3.347133] 14 33
[ 3.347133] 15 32
[ 3.347133] 16 33
[ 3.347133] 17 33
[ 3.347133] 18 34
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/Makefile')
| -rw-r--r-- | kernel/rcu/Makefile | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/rcu/Makefile b/kernel/rcu/Makefile index f91f2c2cf138..ba7d82609cbe 100644 --- a/kernel/rcu/Makefile +++ b/kernel/rcu/Makefile @@ -12,6 +12,7 @@ obj-$(CONFIG_TREE_SRCU) += srcutree.o obj-$(CONFIG_TINY_SRCU) += srcutiny.o obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o obj-$(CONFIG_RCU_PERF_TEST) += rcuperf.o +obj-$(CONFIG_RCU_REF_PERF_TEST) += refperf.o obj-$(CONFIG_TREE_RCU) += tree.o obj-$(CONFIG_TINY_RCU) += tiny.o obj-$(CONFIG_RCU_NEED_SEGCBLIST) += rcu_segcblist.o |