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| author |   Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2013-04-03 22:14:11 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2013-06-10 13:44:56 -0700 |
| commit | 026ad2835ce6202069e7aa0b11f5f1be4de34550 (patch) | |
| tree | 2fbf39aa59eee409d892dbd99b82b31e1261f366 /kernel/rcupdate.c | |
| parent | rcu: Remove "Experimental" flags (diff) | |
| download | linux-dev-026ad2835ce6202069e7aa0b11f5f1be4de34550.tar.xz linux-dev-026ad2835ce6202069e7aa0b11f5f1be4de34550.zip | |
rcu: Drive quiescent-state-forcing delay from HZ
Systems with HZ=100 can have slow bootup times due to the default
three-jiffy delays between quiescent-state forcing attempts. This
commit therefore auto-tunes the RCU_JIFFIES_TILL_FORCE_QS value based
on the value of HZ. However, this would break very large systems that
require more time between quiescent-state forcing attempts. This
commit therefore also ups the default delay by one jiffy for each
256 CPUs that might be on the system (based off of nr_cpu_ids at
runtime, -not- NR_CPUS at build time).
Updated to collapse #ifdefs for RCU_JIFFIES_TILL_FORCE_QS into a
step-function definition as suggested by Josh Triplett.
Reported-by: Paul Mackerras <paulus@au1.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcupdate.c')
0 files changed, 0 insertions, 0 deletions