xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

rcu: Distinguish "rcuo" kthreads by RCU flavor

Browse Source 
Currently, the per-no-CBs-CPU kthreads are named "rcuo" followed by
the CPU number, for example, "rcuo".  This is problematic given that
there are either two or three RCU flavors, each of which gets a per-CPU
kthread with exactly the same name.  This commit therefore introduces
a one-letter abbreviation for each RCU flavor, namely 'b' for RCU-bh,
'p' for RCU-preempt, and 's' for RCU-sched.  This abbreviation is used
to distinguish the "rcuo" kthreads, for example, for CPU 0 we would have
"rcuob/0", "rcuop/0", and "rcuos/0".

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
This commit is contained in:
Paul E. McKenney
2012-12-03 08:16:28 -08:00
committed by Paul E. McKenney
parent 09c7b89062
commit a488985851
5 changed files with 20 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
Documentation/kernel-parameters.txt
View File

@@ -2461,9 +2461,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
In kernels built with CONFIG_RCU_NOCB_CPU=y, set
the specified list of CPUs to be no-callback CPUs.
Invocation of these CPUs' RCU callbacks will
be offloaded to "rcuoN" kthreads created for
that purpose. This reduces OS jitter on the
be offloaded to "rcuox/N" kthreads created for
that purpose, where "x" is "b" for RCU-bh, "p"
for RCU-preempt, and "s" for RCU-sched, and "N"
is the CPU number. This reduces OS jitter on the
offloaded CPUs, which can be useful for HPC and
real-time workloads. It can also improve energy
efficiency for asymmetric multiprocessors.