Increase default RCU batching sharply

Dipankar made RCU limit the batch size to improve latency, but that approach is unworkable: it can cause the RCU queues to grow without bounds, since the batch limiter ended up limiting the callbacks. So make the limit much higher, and start planning on instead limiting the batch size by doing RCU callbacks more often if the queue looks like it might be growing too long.

Linus Torvalds committed 21 years ago

Commit 2cc78eb1 parent de21eb61 file · +1 −1Browse files

Showing the changes to kernel (1 of 1 file). Show all

Unified · Split

kernel/rcupdate.c+1−1

@@ -71,7 +71,7 @@ DEFINE_PER_CPU(struct rcu_data, rcu_bh_data) = { 0L }; · 70 unmodified lines
71		71
72	/* Fake initialization required by compiler */	72	/* Fake initialization required by compiler */
73	static DEFINE_PER_CPU(struct tasklet_struct, rcu_tasklet) = {NULL};	73	static DEFINE_PER_CPU(struct tasklet_struct, rcu_tasklet) = {NULL};
74	static int maxbatch = 10;	74	static int maxbatch = 10000;
75		75
76	#ifndef __HAVE_ARCH_CMPXCHG	76	#ifndef __HAVE_ARCH_CMPXCHG
77	/*	77	/*