RCU Archive on lore.kernel.org
 help / color / Atom feed
From: paulmck@kernel.org
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
	mingo@kernel.org, jiangshanlai@gmail.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@kernel.org>
Subject: [PATCH tip/core/rcu 12/17] torture: Throttle VERBOSE_TOROUT_*() output
Date: Wed,  6 Jan 2021 09:17:05 -0800
Message-ID: <20210106171710.22239-12-paulmck@kernel.org> (raw)
In-Reply-To: <20210106171532.GA20769@paulmck-ThinkPad-P72>

From: "Paul E. McKenney" <paulmck@kernel.org>

This commit adds kernel boot parameters torture.verbose_sleep_frequency
and torture.verbose_sleep_duration, which allow VERBOSE_TOROUT_*() output
to be throttled with periodic sleeps on large systems.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 Documentation/admin-guide/kernel-parameters.txt |  8 ++++++++
 include/linux/torture.h                         | 15 +++++++++++++--
 kernel/torture.c                                | 20 ++++++++++++++++++++
 3 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 29ea816..5ce95dd 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5337,6 +5337,14 @@
 			are running concurrently, especially on systems
 			with rotating-rust storage.
 
+	torture.verbose_sleep_frequency= [KNL]
+			Specifies how many verbose printk()s should be
+			emitted between each sleep.  The default of zero
+			disables verbose-printk() sleeping.
+
+	torture.verbose_sleep_duration= [KNL]
+			Duration of each verbose-printk() sleep in jiffies.
+
 	tp720=		[HW,PS2]
 
 	tpm_suspend_pcr=[HW,TPM]
diff --git a/include/linux/torture.h b/include/linux/torture.h
index 32941f8..d62d13c 100644
--- a/include/linux/torture.h
+++ b/include/linux/torture.h
@@ -32,9 +32,20 @@
 #define TOROUT_STRING(s) \
 	pr_alert("%s" TORTURE_FLAG " %s\n", torture_type, s)
 #define VERBOSE_TOROUT_STRING(s) \
-	do { if (verbose) pr_alert("%s" TORTURE_FLAG " %s\n", torture_type, s); } while (0)
+do {										\
+	if (verbose) {								\
+		verbose_torout_sleep();						\
+		pr_alert("%s" TORTURE_FLAG " %s\n", torture_type, s);		\
+	}									\
+} while (0)
 #define VERBOSE_TOROUT_ERRSTRING(s) \
-	do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! %s\n", torture_type, s); } while (0)
+do {										\
+	if (verbose) {								\
+		verbose_torout_sleep();						\
+		pr_alert("%s" TORTURE_FLAG "!!! %s\n", torture_type, s);	\
+	}									\
+} while (0)
+void verbose_torout_sleep(void);
 
 /* Definitions for online/offline exerciser. */
 typedef void torture_ofl_func(void);
diff --git a/kernel/torture.c b/kernel/torture.c
index 7ad5c96..93eeeb2 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -48,6 +48,12 @@ module_param(disable_onoff_at_boot, bool, 0444);
 static bool ftrace_dump_at_shutdown;
 module_param(ftrace_dump_at_shutdown, bool, 0444);
 
+static int verbose_sleep_frequency;
+module_param(verbose_sleep_frequency, int, 0444);
+
+static int verbose_sleep_duration = 1;
+module_param(verbose_sleep_duration, int, 0444);
+
 static char *torture_type;
 static int verbose;
 
@@ -58,6 +64,20 @@ static int verbose;
 static int fullstop = FULLSTOP_RMMOD;
 static DEFINE_MUTEX(fullstop_mutex);
 
+static atomic_t verbose_sleep_counter;
+
+/*
+ * Sleep if needed from VERBOSE_TOROUT*().
+ */
+void verbose_torout_sleep(void)
+{
+	if (verbose_sleep_frequency > 0 &&
+	    verbose_sleep_duration > 0 &&
+	    !(atomic_inc_return(&verbose_sleep_counter) % verbose_sleep_frequency))
+		schedule_timeout_uninterruptible(verbose_sleep_duration);
+}
+EXPORT_SYMBOL_GPL(verbose_torout_sleep);
+
 /*
  * Schedule a high-resolution-timer sleep in nanoseconds, with a 32-bit
  * nanosecond random fuzz.  This function and its friends desynchronize
-- 
2.9.5


  parent reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-06 17:15 [PATCH tip/core/rcu 0/17] Torture-test updates for v5.12 Paul E. McKenney
2021-01-06 17:16 ` [PATCH tip/core/rcu 01/17] rcutorture: Add testing for RCU's global memory ordering paulmck
2021-01-06 17:16 ` [PATCH tip/core/rcu 02/17] scftorture: Add debug output for wrong-CPU warning paulmck
2021-01-06 17:16 ` [PATCH tip/core/rcu 03/17] refscale: Allow summarization of verbose output paulmck
2021-01-06 17:16 ` [PATCH tip/core/rcu 04/17] rcutorture: Require entire stutter period be post-boot paulmck
2021-01-06 17:16 ` [PATCH tip/core/rcu 05/17] rcutorture: Make synctype[] and nsynctype be static global paulmck
2021-01-06 17:16 ` [PATCH tip/core/rcu 06/17] rcutorture: Make rcu_torture_fakewriter() use blocking wait primitives paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 07/17] torture: Add fuzzed hrtimer-based sleep functions paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 08/17] rcutorture: Use torture_hrtimeout_jiffies() to avoid busy-waits paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 09/17] torture: Make stutter use torture_hrtimeout_*() functions paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 10/17] rcutorture: Use hrtimers for reader and writer delays paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 11/17] torture: Make refscale throttle high-rate printk()s paulmck
2021-01-06 17:17 ` paulmck [this message]
2021-01-06 17:17 ` [PATCH tip/core/rcu 13/17] rcutorture: Make object_debug also double call_rcu() heap object paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 14/17] torture: Clean up after torture-test CPU hotplugging paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 15/17] torture: Maintain torture-specific set of CPUs-online books paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 16/17] torture: Break affinity of kthreads last running on outgoing CPU paulmck
2021-01-06 17:17 ` [PATCH tip/core/rcu 17/17] rcutorture: Add rcutree.use_softirq=0 to RUDE01 and TASKS01 paulmck

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=20210106171710.22239-12-paulmck@kernel.org \
    --to=paulmck@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=dhowells@redhat.com \
    --cc=edumazet@google.com \
    --cc=fweisbec@gmail.com \
    --cc=jiangshanlai@gmail.com \
    --cc=joel@joelfernandes.org \
    --cc=josh@joshtriplett.org \
    --cc=kernel-team@fb.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=mingo@kernel.org \
    --cc=oleg@redhat.com \
    --cc=peterz@infradead.org \
    --cc=rcu@vger.kernel.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

RCU Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/rcu/0 rcu/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 rcu rcu/ https://lore.kernel.org/rcu \
		rcu@vger.kernel.org
	public-inbox-index rcu

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.rcu


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git