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author | Paul E. McKenney <paulmck@linux.ibm.com> | 2019-07-15 01:09:04 -0700 |
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committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2019-08-13 14:38:24 -0700 |
commit | 1d5a81c18dc68fc38a52e8dab1992a043a358927 (patch) | |
tree | 348ced2b4230c636b203b7213bf6b7a12226d4b9 /kernel/cpu.c | |
parent | 23651d9b9616060cf86af5e3b15defcf3bcd2642 (diff) | |
download | linux-1d5a81c18dc68fc38a52e8dab1992a043a358927.tar.bz2 |
rcu/nocb: Reduce nocb_cb_wait() leaf rcu_node ->lock contention
Currently, nocb_cb_wait() advances callbacks on each pass through its
loop, though only if it succeeds in conditionally acquiring its leaf
rcu_node structure's ->lock. Despite the conditional acquisition of
->lock, this does increase contention. This commit therefore avoids
advancing callbacks unless there are callbacks in ->cblist whose grace
period has completed.
Note that nocb_cb_wait() doesn't worry about callbacks that have not
yet been assigned a grace period. The idea is that the only reason for
nocb_cb_wait() to advance callbacks is to allow it to continue invoking
callbacks. Time will tell whether this is the correct choice.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'kernel/cpu.c')
0 files changed, 0 insertions, 0 deletions