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 <paulmck@linux.vnet.ibm.com>
Tested-by: Mike Galbraith <efault@gmx.de>

diff --git a/include/linux/srcuclassic.h b/include/linux/srcuclassic.h
index 41cf99930f342fbf622ac6dd133f0bd5cc74a216..5753f73222629c1340d363eba4e50510e437c575 100644 (file)
--- 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 4f284e4f4d8c5d7003e2ef308e03ab277829922d..42311ee0334fde629280f6b92cdc065853e3ba14 100644 (file)
--- 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 94515ff226fb17a02bfcc7b0143e0157b84c4881..3865717df1244f1b10c7e9aa504021c2ea1c56ea 100644 (file)
--- 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 e9d4527cdd43dfcd2993f48c18094ac2ccf2cdd6..ae6e574d4cf5c3fbdd8ab9a56009981cec9935a1 100644 (file)
--- 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 1c2c1004b3b19756c85d06fc122ca385d68215e6..72b6cce5f59151c581455db2d255fd1f51a75977 100644 (file)
--- 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 23aa02587d0fd245919ce26d26225d49f06a8a6b..91fff49d5869826a25039e8a47a2b14fe6cb7be6 100644 (file)
--- 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);