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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 45/52] rcu: Restructure rcu_check_gp_kthread_starvation() Date: Wed, 29 Aug 2018 15:38:47 -0700 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180829223830.GA1800@linux.vnet.ibm.com> References: <20180829223830.GA1800@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18082922-0068-0000-0000-00000331B957 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009636; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01080744; UDB=6.00557497; IPR=6.00860730; MB=3.00023002; MTD=3.00000008; XFM=3.00000015; UTC=2018-08-29 22:39:02 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18082922-0069-0000-0000-0000458F161C Message-Id: <20180829223854.4055-45-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-1808290220 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This commit removes the rsp and gpa local variables, repurposes the j local variable and adds a gpk (GP kthread) local to improve readability. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 25 +++++++++++-------------- 1 file changed, 11 insertions(+), 14 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 0eccfd02e0b3..488ac7a36835 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1224,24 +1224,21 @@ static const char *gp_state_getname(short gs) */ static void rcu_check_gp_kthread_starvation(void) { - unsigned long gpa; + struct task_struct *gpk = rcu_state.gp_kthread; unsigned long j; - struct rcu_state *rsp = &rcu_state; - j = jiffies; - gpa = READ_ONCE(rsp->gp_activity); - if (j - gpa > 2 * HZ) { + j = jiffies - READ_ONCE(rcu_state.gp_activity); + if (j > 2 * HZ) { pr_err("%s kthread starved for %ld jiffies! g%ld f%#x %s(%d) ->state=%#lx ->cpu=%d\n", - rsp->name, j - gpa, - (long)rcu_seq_current(&rsp->gp_seq), - rsp->gp_flags, - gp_state_getname(rsp->gp_state), rsp->gp_state, - rsp->gp_kthread ? rsp->gp_kthread->state : ~0, - rsp->gp_kthread ? task_cpu(rsp->gp_kthread) : -1); - if (rsp->gp_kthread) { + rcu_state.name, j, + (long)rcu_seq_current(&rcu_state.gp_seq), + rcu_state.gp_flags, + gp_state_getname(rcu_state.gp_state), rcu_state.gp_state, + gpk ? gpk->state : ~0, gpk ? task_cpu(gpk) : -1); + if (gpk) { pr_err("RCU grace-period kthread stack dump:\n"); - sched_show_task(rsp->gp_kthread); - wake_up_process(rsp->gp_kthread); + sched_show_task(gpk); + wake_up_process(gpk); } } } -- 2.17.1