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McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 13/24] rcu: Clean up flavor-related definitions and comments in Kconfig Date: Wed, 29 Aug 2018 15:53:54 -0700 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180829225340.GA7019@linux.vnet.ibm.com> References: <20180829225340.GA7019@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18082922-0072-0000-0000-0000039969A8 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009636; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01080749; UDB=6.00557500; IPR=6.00860734; MB=3.00023002; MTD=3.00000008; XFM=3.00000015; UTC=2018-08-29 22:54:12 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18082922-0073-0000-0000-0000493EB97F Message-Id: <20180829225405.7275-13-paulmck@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-29_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808290223 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Signed-off-by: Paul E. McKenney --- kernel/rcu/Kconfig | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig index a0b7f0103ca9..939a2056c87a 100644 --- a/kernel/rcu/Kconfig +++ b/kernel/rcu/Kconfig @@ -196,7 +196,7 @@ config RCU_BOOST This option boosts the priority of preempted RCU readers that block the current preemptible RCU grace period for too long. This option also prevents heavy loads from blocking RCU - callback invocation for all flavors of RCU. + callback invocation. Say Y here if you are working with real-time apps or heavy loads Say N here if you are unsure. @@ -225,15 +225,15 @@ config RCU_NOCB_CPU callback invocation to energy-efficient CPUs in battery-powered asymmetric multiprocessors. - This option offloads callback invocation from the set of - CPUs specified at boot time by the rcu_nocbs parameter. - For each such CPU, a kthread ("rcuox/N") will be created to - invoke callbacks, where the "N" is the CPU being offloaded, - and where the "p" for RCU-preempt and "s" for RCU-sched. - Nothing prevents this kthread from running on the specified - CPUs, but (1) the kthreads may be preempted between each - callback, and (2) affinity or cgroups can be used to force - the kthreads to run on whatever set of CPUs is desired. + This option offloads callback invocation from the set of CPUs + specified at boot time by the rcu_nocbs parameter. For each + such CPU, a kthread ("rcuox/N") will be created to invoke + callbacks, where the "N" is the CPU being offloaded, and where + the "p" for RCU-preempt (PREEMPT kernels) and "s" for RCU-sched + (!PREEMPT kernels). Nothing prevents this kthread from running + on the specified CPUs, but (1) the kthreads may be preempted + between each callback, and (2) affinity or cgroups can be used + to force the kthreads to run on whatever set of CPUs is desired. Say Y here if you want to help to debug reduced OS jitter. Say N here if you are unsure. -- 2.17.1