From e1286424e0487703d9a14b122b8ec117bc4c64e9 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 18 Apr 2012 16:20:18 -0700 Subject: [PATCH] --- yaml --- r: 302746 b: refs/heads/master c: c9336643e1440f4dfc89ad4ac6185813619abb8c h: refs/heads/master v: v3 --- [refs] | 2 +- trunk/init/Kconfig | 23 +++++++++++++++++++---- 2 files changed, 20 insertions(+), 5 deletions(-) diff --git a/[refs] b/[refs] index abe9394b65dd..5503ab4b0c0b 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: f88022a4f650ac1778cafcc17d2e522283bdf590 +refs/heads/master: c9336643e1440f4dfc89ad4ac6185813619abb8c diff --git a/trunk/init/Kconfig b/trunk/init/Kconfig index 6cfd71d06463..85c6870ed476 100644 --- a/trunk/init/Kconfig +++ b/trunk/init/Kconfig @@ -515,10 +515,25 @@ config RCU_BOOST_PRIO depends on RCU_BOOST default 1 help - This option specifies the real-time priority to which preempted - RCU readers are to be boosted. If you are working with CPU-bound - real-time applications, you should specify a priority higher then - the highest-priority CPU-bound application. + This option specifies the real-time priority to which long-term + preempted RCU readers are to be boosted. If you are working + with a real-time application that has one or more CPU-bound + threads running at a real-time priority level, you should set + RCU_BOOST_PRIO to a priority higher then the highest-priority + real-time CPU-bound thread. The default RCU_BOOST_PRIO value + of 1 is appropriate in the common case, which is real-time + applications that do not have any CPU-bound threads. + + Some real-time applications might not have a single real-time + thread that saturates a given CPU, but instead might have + multiple real-time threads that, taken together, fully utilize + that CPU. In this case, you should set RCU_BOOST_PRIO to + a priority higher than the lowest-priority thread that is + conspiring to prevent the CPU from running any non-real-time + tasks. For example, if one thread at priority 10 and another + thread at priority 5 are between themselves fully consuming + the CPU time on a given CPU, then RCU_BOOST_PRIO should be + set to priority 6 or higher. Specify the real-time priority, or take the default if unsure.