From: Stefan Reiter stefan@pimaker.at
[ Upstream commit 610dea36d3083a977e4f156206cbe1eaa2a532f0 ]
Commit 18cd8c93e69e ("rcu/nocb: Print gp/cb kthread hierarchy if dump_tree") added print statements to rcu_organize_nocb_kthreads for debugging, but incorrectly guarded them, causing the function to always spew out its message.
This patch fixes it by guarding both pr_alert statements with dump_tree, while also changing the second pr_alert to a pr_cont, to print the hierarchy in a single line (assuming that's how it was supposed to work).
Fixes: 18cd8c93e69e ("rcu/nocb: Print gp/cb kthread hierarchy if dump_tree") Signed-off-by: Stefan Reiter stefan@pimaker.at [ paulmck: Make single-nocbs-CPU GP kthreads look less erroneous. ] Signed-off-by: Paul E. McKenney paulmck@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/rcu/tree_plugin.h | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-)
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index f849e7429816f..f7118842a2b88 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2322,6 +2322,8 @@ static void __init rcu_organize_nocb_kthreads(void) { int cpu; bool firsttime = true; + bool gotnocbs = false; + bool gotnocbscbs = true; int ls = rcu_nocb_gp_stride; int nl = 0; /* Next GP kthread. */ struct rcu_data *rdp; @@ -2344,21 +2346,31 @@ static void __init rcu_organize_nocb_kthreads(void) rdp = per_cpu_ptr(&rcu_data, cpu); if (rdp->cpu >= nl) { /* New GP kthread, set up for CBs & next GP. */ + gotnocbs = true; nl = DIV_ROUND_UP(rdp->cpu + 1, ls) * ls; rdp->nocb_gp_rdp = rdp; rdp_gp = rdp; - if (!firsttime && dump_tree) - pr_cont("\n"); - firsttime = false; - pr_alert("%s: No-CB GP kthread CPU %d:", __func__, cpu); + if (dump_tree) { + if (!firsttime) + pr_cont("%s\n", gotnocbscbs + ? "" : " (self only)"); + gotnocbscbs = false; + firsttime = false; + pr_alert("%s: No-CB GP kthread CPU %d:", + __func__, cpu); + } } else { /* Another CB kthread, link to previous GP kthread. */ + gotnocbscbs = true; rdp->nocb_gp_rdp = rdp_gp; rdp_prev->nocb_next_cb_rdp = rdp; - pr_alert(" %d", cpu); + if (dump_tree) + pr_cont(" %d", cpu); } rdp_prev = rdp; } + if (gotnocbs && dump_tree) + pr_cont("%s\n", gotnocbscbs ? "" : " (self only)"); }
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