Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[sfrench/cifs-2.6.git] / Documentation / admin-guide / kernel-parameters.txt
index 6795dedcbd1e0513285a3ee6fbf15f53eda94ac6..4c74a2f4ddfc38c3aaf79fa5f6db10bc524dc78e 100644 (file)
 
                        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 "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.
+                       Invocation of these CPUs' RCU callbacks will be
+                       offloaded to "rcuox/N" kthreads created for that
+                       purpose, where "x" is "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.
 
        rcu_nocb_poll   [KNL]
                        Rather than requiring that offloaded CPUs
                        Set required age in jiffies for a
                        given grace period before RCU starts
                        soliciting quiescent-state help from
-                       rcu_note_context_switch().
+                       rcu_note_context_switch().  If not specified, the
+                       kernel will calculate a value based on the most
+                       recent settings of rcutree.jiffies_till_first_fqs
+                       and rcutree.jiffies_till_next_fqs.
+                       This calculated value may be viewed in
+                       rcutree.jiffies_to_sched_qs.  Any attempt to
+                       set rcutree.jiffies_to_sched_qs will be
+                       cheerfully overwritten.
 
        rcutree.jiffies_till_first_fqs= [KNL]
                        Set delay from grace-period initialization to
        rcupdate.rcu_self_test= [KNL]
                        Run the RCU early boot self tests
 
-       rcupdate.rcu_self_test_bh= [KNL]
-                       Run the RCU bh early boot self tests
-
-       rcupdate.rcu_self_test_sched= [KNL]
-                       Run the RCU sched early boot self tests
-
        rdinit=         [KNL]
                        Format: <full_path>
                        Run specified binary instead of /init from the ramdisk,