From: "Paul E. McKenney" <paulmck@linux.ibm.com>
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" <paulmck@linux.ibm.com>
Subject: [PATCH tip/core/rcu 04/14] rcu: Parameterize rcu_check_gp_start_stall()
Date: Sun, 11 Nov 2018 11:28:54 -0800 [thread overview]
Message-ID: <20181111192904.3199-4-paulmck@linux.ibm.com> (raw)
In-Reply-To: <20181111192839.GA32144@linux.ibm.com>
In order to debug forward-progress stalls, it is necessary to check
for excessively delayed grace-period starts. This is currently done
for RCU CPU stall warnings by rcu_check_gp_start_stall(), which checks
to see if the start of a requested grace period has been delayed by an
RCU CPU stall warning period. Because rcutorture will need to check
for the time consumed by an RCU forward-progress delay, this commit
promotes gpssdelay from a local variable to a formal parameter. It is
not necessary to export rcu_check_gp_start_stall() because rcutorture
will access it via a wrapper function.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
kernel/rcu/tree.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 4933f5d9d992..36e30150e1e9 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2600,10 +2600,10 @@ static void force_quiescent_state(void)
* This function checks for grace-period requests that fail to motivate
* RCU to come out of its idle mode.
*/
-static void
-rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp)
+void
+rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp,
+ const unsigned long gpssdelay)
{
- const unsigned long gpssdelay = rcu_jiffies_till_stall_check();
unsigned long flags;
unsigned long j;
struct rcu_node *rnp_root = rcu_get_root();
@@ -2690,7 +2690,7 @@ static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused
local_irq_restore(flags);
}
- rcu_check_gp_start_stall(rnp, rdp);
+ rcu_check_gp_start_stall(rnp, rdp, rcu_jiffies_till_stall_check());
/* If there are callbacks ready, invoke them. */
if (rcu_segcblist_ready_cbs(&rdp->cblist))
--
2.17.1
next prev parent reply other threads:[~2018-11-11 19:30 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-11 19:28 [PATCH tip/core/rcu 0/14] Miscellaneous fixes for v4.21/v5.0 Paul E. McKenney
2018-11-11 19:28 ` [PATCH tip/core/rcu 01/14] rcu: Stop expedited grace periods from relying on stop-machine Paul E. McKenney
2018-11-11 19:28 ` [PATCH tip/core/rcu 02/14] MAINTAINERS: Update from @linux.vnet.ibm.com to @linux.ibm.com Paul E. McKenney
2018-11-11 19:28 ` [PATCH tip/core/rcu 03/14] rcu: Avoid double multiply by HZ Paul E. McKenney
2018-11-11 19:28 ` Paul E. McKenney [this message]
2018-11-11 19:28 ` [PATCH tip/core/rcu 05/14] rcu: Add state name to show_rcu_gp_kthreads() output Paul E. McKenney
2018-11-11 19:28 ` [PATCH tip/core/rcu 06/14] rcu: Add jiffies-since-GP-activity to show_rcu_gp_kthreads() Paul E. McKenney
2018-11-11 19:28 ` [PATCH tip/core/rcu 07/14] rcu: Adjust the comment of function rcu_is_watching Paul E. McKenney
2018-11-11 19:28 ` [PATCH tip/core/rcu 08/14] rcu: Trace end of grace period before end of grace period Paul E. McKenney
2018-11-11 19:28 ` [PATCH tip/core/rcu 09/14] rcu: Speed up expedited GPs when interrupting RCU reader Paul E. McKenney
2018-11-11 19:29 ` [PATCH tip/core/rcu 10/14] rcu: Replace this_cpu_ptr() with __this_cpu_read() Paul E. McKenney
2018-11-11 19:29 ` [PATCH tip/core/rcu 11/14] rcu: Avoid signed integer overflow in rcu_preempt_deferred_qs() Paul E. McKenney
2018-11-11 19:29 ` [PATCH tip/core/rcu 12/14] MAINTAINERS: Add Joel Fernandes as RCU reviewer Paul E. McKenney
2018-11-11 19:29 ` [PATCH tip/core/rcu 13/14] checkpatch: Create table of obsolete APIs and apply to RCU Paul E. McKenney
2018-11-11 19:29 ` [PATCH tip/core/rcu 14/14] checkpatch.pl: Suggest lockdep instead of asserting !spin_is_locked() 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=20181111192904.3199-4-paulmck@linux.ibm.com \
--to=paulmck@linux.ibm.com \
--cc=akpm@linux-foundation.org \
--cc=dhowells@redhat.com \
--cc=dipankar@in.ibm.com \
--cc=edumazet@google.com \
--cc=fweisbec@gmail.com \
--cc=jiangshanlai@gmail.com \
--cc=joel@joelfernandes.org \
--cc=josh@joshtriplett.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=mingo@kernel.org \
--cc=oleg@redhat.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
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;
as well as URLs for NNTP newsgroup(s).