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Message-ID: <53C3DA88.8060004@gmail.com>
Date: Mon, 14 Jul 2014 09:26:32 -0400
From: Pranith Kumar <bobby.prani@...il.com>
To: Joe Perches <joe@...ches.com>
CC: Josh Triplett <josh@...edesktop.org>,
"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
Steven Rostedt <rostedt@...dmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
Lai Jiangshan <laijs@...fujitsu.com>,
Iulia Manda <iulia.manda21@...il.com>,
open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/1] rcutorture: fixes for printing message buffer
On 07/11/2014 04:37 PM, Joe Perches wrote:
> On Fri, 2014-07-11 at 16:30 -0400, Pranith Kumar wrote:
>> Use snprintf() instead of sprintf() for writing to the message buffer.
>> Also use vmalloc() for the allocation of the message buffer. Since pr_alert() is
>> limited to print LOG_LINE_MAX characters at a time, we print the buffer in a
>> loop one line at a time.
>>
>> I tested this using the parse-torture.sh script as follows:
>
> Did you see the patch I sent you?
> https://lkml.org/lkml/2014/6/20/604
>
> It doesn't need a vmalloc.
> What is wrong with that approach?
>
>
Hi Paul,
Please find an alternative patch as suggested by Joe.
>From 0a3050d5ac910cb5f488e0a0dfe44cde06af1259 Mon Sep 17 00:00:00 2001
From: Pranith Kumar <bobby.prani@...il.com>
Date: Mon, 14 Jul 2014 09:16:15 -0400
Subject: [PATCH 1/1] rcu: Use pr_alert/pr_cont for printing logs
User pr_alert/pr_cont for printing the logs from rcutorture module directly
instead of writing it to a buffer and then printing it. This allows us from not
having to allocate such buffers. Also remove a resulting empty function.
I tested this using the parse-torture.sh script as follows:
$ dmesg | grep torture > log.txt
$ bash parse-torture.sh log.txt test
$
There were no warnings which means that parsing went fine.
Signed-off-by: Joe Percesh <joe@...ches.com>
Signed-off-by: Pranith Kumar <bobby.prani@...il.com>
---
include/linux/torture.h | 2 +-
kernel/rcu/rcutorture.c | 127 +++++++++++++++++++++---------------------------
kernel/torture.c | 16 +++---
3 files changed, 64 insertions(+), 81 deletions(-)
diff --git a/include/linux/torture.h b/include/linux/torture.h
index 5ca58fc..fec46f8 100644
--- a/include/linux/torture.h
+++ b/include/linux/torture.h
@@ -51,7 +51,7 @@
/* Definitions for online/offline exerciser. */
int torture_onoff_init(long ooholdoff, long oointerval);
-char *torture_onoff_stats(char *page);
+void torture_onoff_stats(void);
bool torture_onoff_failures(void);
/* Low-rider random number generator. */
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 5ec0452..3e35f1b 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -242,7 +242,7 @@ struct rcu_torture_ops {
void (*call)(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
void (*cb_barrier)(void);
void (*fqs)(void);
- void (*stats)(char *page);
+ void (*stats)(void);
int irq_capable;
int can_boost;
const char *name;
@@ -525,21 +525,21 @@ static void srcu_torture_barrier(void)
srcu_barrier(&srcu_ctl);
}
-static void srcu_torture_stats(char *page)
+static void srcu_torture_stats(void)
{
int cpu;
int idx = srcu_ctl.completed & 0x1;
- page += sprintf(page, "%s%s per-CPU(idx=%d):",
- torture_type, TORTURE_FLAG, idx);
+ pr_alert("%s%s per-CPU(idx=%d):",
+ torture_type, TORTURE_FLAG, idx);
for_each_possible_cpu(cpu) {
long c0, c1;
c0 = (long)per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx];
c1 = (long)per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx];
- page += sprintf(page, " %d(%ld,%ld)", cpu, c0, c1);
+ pr_cont(" %d(%ld,%ld)", cpu, c0, c1);
}
- sprintf(page, "\n");
+ pr_cont("\n");
}
static void srcu_torture_synchronize_expedited(void)
@@ -1031,10 +1031,15 @@ rcu_torture_reader(void *arg)
}
/*
- * Create an RCU-torture statistics message in the specified buffer.
+ * Print torture statistics. Caller must ensure that there is only
+ * one call to this function at a given time!!! This is normally
+ * accomplished by relying on the module system to only have one copy
+ * of the module loaded, and then by giving the rcu_torture_stats
+ * kthread full control (or the init/cleanup functions when rcu_torture_stats
+ * thread is not running).
*/
static void
-rcu_torture_printk(char *page)
+rcu_torture_stats_print(void)
{
int cpu;
int i;
@@ -1052,55 +1057,60 @@ rcu_torture_printk(char *page)
if (pipesummary[i] != 0)
break;
}
- page += sprintf(page, "%s%s ", torture_type, TORTURE_FLAG);
- page += sprintf(page,
- "rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
- rcu_torture_current,
- rcu_torture_current_version,
- list_empty(&rcu_torture_freelist),
- atomic_read(&n_rcu_torture_alloc),
- atomic_read(&n_rcu_torture_alloc_fail),
- atomic_read(&n_rcu_torture_free));
- page += sprintf(page, "rtmbe: %d rtbke: %ld rtbre: %ld ",
- atomic_read(&n_rcu_torture_mberror),
- n_rcu_torture_boost_ktrerror,
- n_rcu_torture_boost_rterror);
- page += sprintf(page, "rtbf: %ld rtb: %ld nt: %ld ",
- n_rcu_torture_boost_failure,
- n_rcu_torture_boosts,
- n_rcu_torture_timers);
- page = torture_onoff_stats(page);
- page += sprintf(page, "barrier: %ld/%ld:%ld",
- n_barrier_successes,
- n_barrier_attempts,
- n_rcu_torture_barrier_error);
- page += sprintf(page, "\n%s%s ", torture_type, TORTURE_FLAG);
+
+ pr_alert("%s%s ", torture_type, TORTURE_FLAG);
+ pr_cont("rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
+ rcu_torture_current,
+ rcu_torture_current_version,
+ list_empty(&rcu_torture_freelist),
+ atomic_read(&n_rcu_torture_alloc),
+ atomic_read(&n_rcu_torture_alloc_fail),
+ atomic_read(&n_rcu_torture_free));
+ pr_cont("rtmbe: %d rtbke: %ld rtbre: %ld ",
+ atomic_read(&n_rcu_torture_mberror),
+ n_rcu_torture_boost_ktrerror,
+ n_rcu_torture_boost_rterror);
+ pr_cont("rtbf: %ld rtb: %ld nt: %ld ",
+ n_rcu_torture_boost_failure,
+ n_rcu_torture_boosts,
+ n_rcu_torture_timers);
+ torture_onoff_stats();
+ pr_cont("barrier: %ld/%ld:%ld\n",
+ n_barrier_successes,
+ n_barrier_attempts,
+ n_rcu_torture_barrier_error);
+
+ pr_alert("%s%s ", torture_type, TORTURE_FLAG);
if (atomic_read(&n_rcu_torture_mberror) != 0 ||
n_rcu_torture_barrier_error != 0 ||
n_rcu_torture_boost_ktrerror != 0 ||
n_rcu_torture_boost_rterror != 0 ||
n_rcu_torture_boost_failure != 0 ||
i > 1) {
- page += sprintf(page, "!!! ");
+ pr_cont("%s", "!!! ");
atomic_inc(&n_rcu_torture_error);
WARN_ON_ONCE(1);
}
- page += sprintf(page, "Reader Pipe: ");
+ pr_cont("Reader Pipe: ");
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
- page += sprintf(page, " %ld", pipesummary[i]);
- page += sprintf(page, "\n%s%s ", torture_type, TORTURE_FLAG);
- page += sprintf(page, "Reader Batch: ");
+ pr_cont(" %ld", pipesummary[i]);
+ pr_cont("\n");
+
+ pr_alert("%s%s ", torture_type, TORTURE_FLAG);
+ pr_cont("Reader Batch: ");
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
- page += sprintf(page, " %ld", batchsummary[i]);
- page += sprintf(page, "\n%s%s ", torture_type, TORTURE_FLAG);
- page += sprintf(page, "Free-Block Circulation: ");
+ pr_cont(" %ld", batchsummary[i]);
+ pr_cont("\n");
+
+ pr_alert("%s%s ", torture_type, TORTURE_FLAG);
+ pr_cont("Free-Block Circulation: ");
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
- page += sprintf(page, " %d",
- atomic_read(&rcu_torture_wcount[i]));
+ pr_cont(" %d", atomic_read(&rcu_torture_wcount[i]));
}
- page += sprintf(page, "\n");
+ pr_cont("\n");
+
if (cur_ops->stats)
- cur_ops->stats(page);
+ cur_ops->stats();
if (rtcv_snap == rcu_torture_current_version &&
rcu_torture_current != NULL) {
int __maybe_unused flags;
@@ -1109,10 +1119,9 @@ rcu_torture_printk(char *page)
rcutorture_get_gp_data(cur_ops->ttype,
&flags, &gpnum, &completed);
- page += sprintf(page,
- "??? Writer stall state %d g%lu c%lu f%#x\n",
- rcu_torture_writer_state,
- gpnum, completed, flags);
+ pr_alert("??? Writer stall state %d g%lu c%lu f%#x\n",
+ rcu_torture_writer_state,
+ gpnum, completed, flags);
show_rcu_gp_kthreads();
rcutorture_trace_dump();
}
@@ -1120,30 +1129,6 @@ rcu_torture_printk(char *page)
}
/*
- * Print torture statistics. Caller must ensure that there is only
- * one call to this function at a given time!!! This is normally
- * accomplished by relying on the module system to only have one copy
- * of the module loaded, and then by giving the rcu_torture_stats
- * kthread full control (or the init/cleanup functions when rcu_torture_stats
- * thread is not running).
- */
-static void
-rcu_torture_stats_print(void)
-{
- int size = nr_cpu_ids * 200 + 8192;
- char *buf;
-
- buf = kmalloc(size, GFP_KERNEL);
- if (!buf) {
- pr_err("rcu-torture: Out of memory, need: %d", size);
- return;
- }
- rcu_torture_printk(buf);
- pr_alert("%s", buf);
- kfree(buf);
-}
-
-/*
* Periodically prints torture statistics, if periodic statistics printing
* was specified via the stat_interval module parameter.
*/
diff --git a/kernel/torture.c b/kernel/torture.c
index d600af2..ede8b25 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -211,18 +211,16 @@ EXPORT_SYMBOL_GPL(torture_onoff_cleanup);
/*
* Print online/offline testing statistics.
*/
-char *torture_onoff_stats(char *page)
+void torture_onoff_stats(void)
{
#ifdef CONFIG_HOTPLUG_CPU
- page += sprintf(page,
- "onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ",
- n_online_successes, n_online_attempts,
- n_offline_successes, n_offline_attempts,
- min_online, max_online,
- min_offline, max_offline,
- sum_online, sum_offline, HZ);
+ pr_cont("onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ",
+ n_online_successes, n_online_attempts,
+ n_offline_successes, n_offline_attempts,
+ min_online, max_online,
+ min_offline, max_offline,
+ sum_online, sum_offline, HZ);
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
- return page;
}
EXPORT_SYMBOL_GPL(torture_onoff_stats);
--
2.0.1
--
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