forked from Minki/linux
e6e78b004f
This test runs kfree_rcu() in a loop to measure performance of the new kfree_rcu() batching functionality. The following table shows results when booting with arguments: rcuperf.kfree_loops=20000 rcuperf.kfree_alloc_num=8000 rcuperf.kfree_rcu_test=1 rcuperf.kfree_no_batch=X rcuperf.kfree_no_batch=X # Grace Periods Test Duration (s) X=1 (old behavior) 9133 11.5 X=0 (new behavior) 1732 12.5 On a 16 CPU system with the above boot parameters, we see that the total number of grace periods that elapse during the test drops from 9133 when not batching to 1732 when batching (a 5X improvement). The kfree_rcu() flood itself slows down a bit when batching, though, as shown. Note that the active memory consumption during the kfree_rcu() flood does increase to around 200-250MB due to the batching (from around 50MB without batching). However, this memory consumption is relatively constant. In other words, the system is able to keep up with the kfree_rcu() load. The memory consumption comes down considerably if KFREE_DRAIN_JIFFIES is increased from HZ/50 to HZ/80. A later patch will reduce memory consumption further by using multiple lists. Also, when running the test, please disable CONFIG_DEBUG_PREEMPT and CONFIG_PROVE_RCU for realistic comparisons with/without batching. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
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| .. | ||
| Kconfig | ||
| Kconfig.debug | ||
| Makefile | ||
| rcu_segcblist.c | ||
| rcu_segcblist.h | ||
| rcu.h | ||
| rcuperf.c | ||
| rcutorture.c | ||
| srcutiny.c | ||
| srcutree.c | ||
| sync.c | ||
| tiny.c | ||
| tree_exp.h | ||
| tree_plugin.h | ||
| tree_stall.h | ||
| tree.c | ||
| tree.h | ||
| update.c | ||