From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753961AbaHMVRb (ORCPT ); Wed, 13 Aug 2014 17:17:31 -0400 Received: from e38.co.us.ibm.com ([32.97.110.159]:52198 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753917AbaHMVR2 (ORCPT ); Wed, 13 Aug 2014 17:17:28 -0400 Date: Wed, 13 Aug 2014 14:17:24 -0700 From: "Paul E. McKenney" To: Pranith Kumar Cc: Joe Perches , Josh Triplett , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Iulia Manda , open list Subject: Re: [PATCH 1/1] rcutorture: fixes for printing message buffer Message-ID: <20140813211724.GV4752@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1405110617-16498-1-git-send-email-bobby.prani@gmail.com> <1405111021.2796.23.camel@joe-AO725> <53C3DA88.8060004@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53C3DA88.8060004@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14081321-1344-0000-0000-0000037264F8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 14, 2014 at 09:26:32AM -0400, Pranith Kumar wrote: > 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. Queued for 3.18, thank you both! Thanx, Paul > >From 0a3050d5ac910cb5f488e0a0dfe44cde06af1259 Mon Sep 17 00:00:00 2001 > From: Pranith Kumar > 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 > Signed-off-by: Pranith Kumar > --- > 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 >