From 7f6733c3c648ddd6cf459c1b80ad388a95452955 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 18 Apr 2017 17:17:35 -0700 Subject: [PATCH] srcu: Make rcutorture writer stalls print SRCU GP state In the past, SRCU was simple enough that there was little point in making the rcutorture writer stall messages print the SRCU grace-period number state. With the advent of Tree SRCU, this has changed. This commit therefore makes Classic, Tiny, and Tree SRCU report this state to rcutorture as needed. Signed-off-by: Paul E. McKenney Tested-by: Mike Galbraith --- include/linux/srcuclassic.h | 14 ++++++++++++++ include/linux/srcutiny.h | 12 ++++++++++++ include/linux/srcutree.h | 4 ++++ kernel/rcu/rcutorture.c | 8 +++++--- kernel/rcu/srcutree.c | 13 +++++++++++++ kernel/rcu/tree.c | 12 ++++-------- 6 files changed, 52 insertions(+), 11 deletions(-) diff --git a/include/linux/srcuclassic.h b/include/linux/srcuclassic.h index 41cf99930f34..5753f7322262 100644 --- a/include/linux/srcuclassic.h +++ b/include/linux/srcuclassic.h @@ -98,4 +98,18 @@ void synchronize_srcu_expedited(struct srcu_struct *sp); void srcu_barrier(struct srcu_struct *sp); unsigned long srcu_batches_completed(struct srcu_struct *sp); +static inline void srcutorture_get_gp_data(enum rcutorture_type test_type, + struct srcu_struct *sp, int *flags, + unsigned long *gpnum, + unsigned long *completed) +{ + if (test_type != SRCU_FLAVOR) + return; + *flags = 0; + *completed = sp->completed; + *gpnum = *completed; + if (sp->batch_queue.head || sp->batch_check0.head || sp->batch_check0.head) + (*gpnum)++; +} + #endif diff --git a/include/linux/srcutiny.h b/include/linux/srcutiny.h index 4f284e4f4d8c..42311ee0334f 100644 --- a/include/linux/srcutiny.h +++ b/include/linux/srcutiny.h @@ -78,4 +78,16 @@ static inline unsigned long srcu_batches_completed(struct srcu_struct *sp) return 0; } +static inline void srcutorture_get_gp_data(enum rcutorture_type test_type, + struct srcu_struct *sp, int *flags, + unsigned long *gpnum, + unsigned long *completed) +{ + if (test_type != SRCU_FLAVOR) + return; + *flags = 0; + *completed = sp->srcu_gp_seq; + *gpnum = *completed; +} + #endif diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index 94515ff226fb..3865717df124 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -140,4 +140,8 @@ void synchronize_srcu_expedited(struct srcu_struct *sp); void srcu_barrier(struct srcu_struct *sp); unsigned long srcu_batches_completed(struct srcu_struct *sp); +void srcutorture_get_gp_data(enum rcutorture_type test_type, + struct srcu_struct *sp, int *flags, + unsigned long *gpnum, unsigned long *completed); + #endif diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index e9d4527cdd43..ae6e574d4cf5 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1360,12 +1360,14 @@ rcu_torture_stats_print(void) cur_ops->stats(); if (rtcv_snap == rcu_torture_current_version && rcu_torture_current != NULL) { - int __maybe_unused flags; - unsigned long __maybe_unused gpnum; - unsigned long __maybe_unused completed; + int __maybe_unused flags = 0; + unsigned long __maybe_unused gpnum = 0; + unsigned long __maybe_unused completed = 0; rcutorture_get_gp_data(cur_ops->ttype, &flags, &gpnum, &completed); + srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, + &flags, &gpnum, &completed); wtp = READ_ONCE(writer_task); pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x ->state %#lx\n", rcu_torture_writer_state_getname(), diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 1c2c1004b3b1..72b6cce5f591 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -1011,3 +1011,16 @@ void process_srcu(struct work_struct *work) srcu_reschedule(sp, atomic_read(&sp->srcu_exp_cnt) ? 0 : SRCU_INTERVAL); } EXPORT_SYMBOL_GPL(process_srcu); + +void srcutorture_get_gp_data(enum rcutorture_type test_type, + struct srcu_struct *sp, int *flags, + unsigned long *gpnum, + unsigned long *completed) +{ + if (test_type != SRCU_FLAVOR) + return; + *flags = 0; + *completed = rcu_seq_ctr(sp->srcu_gp_seq); + *gpnum = rcu_seq_ctr(sp->srcu_gp_seq_needed); +} +EXPORT_SYMBOL_GPL(srcutorture_get_gp_data); diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 23aa02587d0f..91fff49d5869 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -704,15 +704,11 @@ void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags, default: break; } - if (rsp != NULL) { - *flags = READ_ONCE(rsp->gp_flags); - *gpnum = READ_ONCE(rsp->gpnum); - *completed = READ_ONCE(rsp->completed); + if (rsp == NULL) return; - } - *flags = 0; - *gpnum = 0; - *completed = 0; + *flags = READ_ONCE(rsp->gp_flags); + *gpnum = READ_ONCE(rsp->gpnum); + *completed = READ_ONCE(rsp->completed); } EXPORT_SYMBOL_GPL(rcutorture_get_gp_data);