From: Stephen Rothwell <sfr@canb•auug.org.au>
To: "Paul E. McKenney" <paulmck@kernel•org>, Petr Mladek <pmladek@suse•com>
Cc: John Ogness <john.ogness@linutronix•de>,
Linux Kernel Mailing List <linux-kernel@vger•kernel.org>,
Linux Next Mailing List <linux-next@vger•kernel.org>
Subject: linux-next: manual merge of the paulmck tree with the printk tree
Date: Wed, 3 Jul 2024 13:18:20 +1000 [thread overview]
Message-ID: <20240703131820.02eb8021@canb.auug.org.au> (raw)
[-- Attachment #1: Type: text/plain, Size: 5566 bytes --]
Hi all,
Today's linux-next merge of the paulmck tree got a conflict in:
kernel/rcu/tree_exp.h
between commit:
9a30ceb4d93e ("rcu: Mark emergency sections in rcu stalls")
from the printk tree and commit:
c19a6725b019 ("rcu: Extract synchronize_rcu_expedited_stall() from synchronize_rcu_expedited_wait()")
from the paulmck tree.
I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging. You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.
--
Cheers,
Stephen Rothwell
diff --cc kernel/rcu/tree_exp.h
index be2d251e84f8,d4be644afb50..000000000000
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@@ -543,6 -542,69 +543,70 @@@ static bool synchronize_rcu_expedited_w
return false;
}
+ /*
+ * Print out an expedited RCU CPU stall warning message.
+ */
+ static void synchronize_rcu_expedited_stall(unsigned long jiffies_start, unsigned long j)
+ {
+ int cpu;
+ unsigned long mask;
+ int ndetected;
+ struct rcu_node *rnp;
+ struct rcu_node *rnp_root = rcu_get_root();
+
+ if (READ_ONCE(csd_lock_suppress_rcu_stall) && csd_lock_is_stuck()) {
+ pr_err("INFO: %s detected expedited stalls, but suppressed full report due to a stuck CSD-lock.\n", rcu_state.name);
+ return;
+ }
+ pr_err("INFO: %s detected expedited stalls on CPUs/tasks: {", rcu_state.name);
+ ndetected = 0;
+ rcu_for_each_leaf_node(rnp) {
+ ndetected += rcu_print_task_exp_stall(rnp);
+ for_each_leaf_node_possible_cpu(rnp, cpu) {
+ struct rcu_data *rdp;
+
+ mask = leaf_node_cpu_bit(rnp, cpu);
+ if (!(READ_ONCE(rnp->expmask) & mask))
+ continue;
+ ndetected++;
+ rdp = per_cpu_ptr(&rcu_data, cpu);
+ pr_cont(" %d-%c%c%c%c", cpu,
+ "O."[!!cpu_online(cpu)],
+ "o."[!!(rdp->grpmask & rnp->expmaskinit)],
+ "N."[!!(rdp->grpmask & rnp->expmaskinitnext)],
+ "D."[!!data_race(rdp->cpu_no_qs.b.exp)]);
+ }
+ }
+ pr_cont(" } %lu jiffies s: %lu root: %#lx/%c\n",
+ j - jiffies_start, rcu_state.expedited_sequence, data_race(rnp_root->expmask),
+ ".T"[!!data_race(rnp_root->exp_tasks)]);
+ if (ndetected) {
+ pr_err("blocking rcu_node structures (internal RCU debug):");
+ rcu_for_each_node_breadth_first(rnp) {
+ if (rnp == rnp_root)
+ continue; /* printed unconditionally */
+ if (sync_rcu_exp_done_unlocked(rnp))
+ continue;
+ pr_cont(" l=%u:%d-%d:%#lx/%c",
+ rnp->level, rnp->grplo, rnp->grphi, data_race(rnp->expmask),
+ ".T"[!!data_race(rnp->exp_tasks)]);
+ }
+ pr_cont("\n");
+ }
+ rcu_for_each_leaf_node(rnp) {
+ for_each_leaf_node_possible_cpu(rnp, cpu) {
+ mask = leaf_node_cpu_bit(rnp, cpu);
+ if (!(READ_ONCE(rnp->expmask) & mask))
+ continue;
+ preempt_disable(); // For smp_processor_id() in dump_cpu_task().
+ dump_cpu_task(cpu);
+ preempt_enable();
++ nbcon_cpu_emergency_flush();
+ }
+ rcu_exp_print_detail_task_stall_rnp(rnp);
+ }
+ }
+
/*
* Wait for the expedited grace period to elapse, issuing any needed
* RCU CPU stall warnings along the way.
@@@ -597,60 -654,8 +659,11 @@@ static void synchronize_rcu_expedited_w
j = jiffies;
rcu_stall_notifier_call_chain(RCU_STALL_NOTIFY_EXP, (void *)(j - jiffies_start));
trace_rcu_stall_warning(rcu_state.name, TPS("ExpeditedStall"));
- pr_err("INFO: %s detected expedited stalls on CPUs/tasks: {",
- rcu_state.name);
- ndetected = 0;
- rcu_for_each_leaf_node(rnp) {
- ndetected += rcu_print_task_exp_stall(rnp);
- for_each_leaf_node_possible_cpu(rnp, cpu) {
- struct rcu_data *rdp;
-
- mask = leaf_node_cpu_bit(rnp, cpu);
- if (!(READ_ONCE(rnp->expmask) & mask))
- continue;
- ndetected++;
- rdp = per_cpu_ptr(&rcu_data, cpu);
- pr_cont(" %d-%c%c%c%c", cpu,
- "O."[!!cpu_online(cpu)],
- "o."[!!(rdp->grpmask & rnp->expmaskinit)],
- "N."[!!(rdp->grpmask & rnp->expmaskinitnext)],
- "D."[!!data_race(rdp->cpu_no_qs.b.exp)]);
- }
- }
- pr_cont(" } %lu jiffies s: %lu root: %#lx/%c\n",
- j - jiffies_start, rcu_state.expedited_sequence,
- data_race(rnp_root->expmask),
- ".T"[!!data_race(rnp_root->exp_tasks)]);
- if (ndetected) {
- pr_err("blocking rcu_node structures (internal RCU debug):");
- rcu_for_each_node_breadth_first(rnp) {
- if (rnp == rnp_root)
- continue; /* printed unconditionally */
- if (sync_rcu_exp_done_unlocked(rnp))
- continue;
- pr_cont(" l=%u:%d-%d:%#lx/%c",
- rnp->level, rnp->grplo, rnp->grphi,
- data_race(rnp->expmask),
- ".T"[!!data_race(rnp->exp_tasks)]);
- }
- pr_cont("\n");
- }
- rcu_for_each_leaf_node(rnp) {
- for_each_leaf_node_possible_cpu(rnp, cpu) {
- mask = leaf_node_cpu_bit(rnp, cpu);
- if (!(READ_ONCE(rnp->expmask) & mask))
- continue;
- preempt_disable(); // For smp_processor_id() in dump_cpu_task().
- dump_cpu_task(cpu);
- preempt_enable();
- nbcon_cpu_emergency_flush();
- }
- rcu_exp_print_detail_task_stall_rnp(rnp);
- }
+ synchronize_rcu_expedited_stall(jiffies_start, j);
jiffies_stall = 3 * rcu_exp_jiffies_till_stall_check() + 3;
+
+ nbcon_cpu_emergency_exit();
+
panic_on_rcu_stall();
}
}
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
next reply other threads:[~2024-07-03 3:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-03 3:18 Stephen Rothwell [this message]
2024-07-03 17:17 ` linux-next: manual merge of the paulmck tree with the printk tree Paul E. McKenney
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240703131820.02eb8021@canb.auug.org.au \
--to=sfr@canb$(echo .)auug.org.au \
--cc=john.ogness@linutronix$(echo .)de \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=linux-next@vger$(echo .)kernel.org \
--cc=paulmck@kernel$(echo .)org \
--cc=pmladek@suse$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox