From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755417AbZAJWcB (ORCPT ); Sat, 10 Jan 2009 17:32:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751705AbZAJWbx (ORCPT ); Sat, 10 Jan 2009 17:31:53 -0500 Received: from e3.ny.us.ibm.com ([32.97.182.143]:59524 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752556AbZAJWbw (ORCPT ); Sat, 10 Jan 2009 17:31:52 -0500 Date: Sat, 10 Jan 2009 14:31:52 -0800 From: "Paul E. McKenney" To: Li Zefan Cc: Ingo Molnar , LKML Subject: Re: [PATCH] rcu: convert rcupreempt trace to seq file Message-ID: <20090110223151.GD7061@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <496852DE.7080802@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <496852DE.7080802@cn.fujitsu.com> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 10, 2009 at 03:48:46PM +0800, Li Zefan wrote: > Impact: also fix a bug in show_rcustats() > > Use seq file for simplification, and the global buffer and mutex can be > removed. Looks very good, and passes my tests. > While doing this, I found rcustats will never show 'ggp' and 'rcc' fields > due to a bug in show_rcustats(). Good eyes! The only change I ask is that you pull the contents of rcupreempt_debugfs_init() into the now-one-line rcupreempt_trace_init(). With that change: Tested-by: Paul E. McKenney Reviewed-by: Paul E. McKenney > Signed-off-by: Li Zefan > --- > kernel/rcupreempt_trace.c | 155 ++++++++++++++++++++------------------------- > 1 files changed, 69 insertions(+), 86 deletions(-) > > diff --git a/kernel/rcupreempt_trace.c b/kernel/rcupreempt_trace.c > index 7c2665c..a0c8297 100644 > --- a/kernel/rcupreempt_trace.c > +++ b/kernel/rcupreempt_trace.c > @@ -39,13 +39,9 @@ > #include > #include > #include > -#include > #include > #include > - > -static struct mutex rcupreempt_trace_mutex; > -static char *rcupreempt_trace_buf; > -#define RCUPREEMPT_TRACE_BUF_SIZE 4096 > +#include > > void rcupreempt_trace_move2done(struct rcupreempt_trace *trace) > { > @@ -170,110 +166,107 @@ static void rcupreempt_trace_sum(struct rcupreempt_trace *sp) > } > } > > -static ssize_t rcustats_read(struct file *filp, char __user *buffer, > - size_t count, loff_t *ppos) > +static ssize_t show_rcustats(struct seq_file *m, void *unused) > { > struct rcupreempt_trace trace; > - ssize_t bcount; > - int cnt = 0; > > rcupreempt_trace_sum(&trace); > - mutex_lock(&rcupreempt_trace_mutex); > - snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt, > - "ggp=%ld rcc=%ld\n", > - rcu_batches_completed(), > - trace.rcu_check_callbacks); > - snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt, > - "na=%ld nl=%ld wa=%ld wl=%ld da=%ld dl=%ld dr=%ld di=%d\n" > - "1=%d e1=%d i1=%ld ie1=%ld g1=%ld a1=%ld ae1=%ld a2=%ld\n" > - "z1=%ld ze1=%ld z2=%ld m1=%ld me1=%ld m2=%ld\n", > > - trace.next_add, trace.next_length, > - trace.wait_add, trace.wait_length, > - trace.done_add, trace.done_length, > - trace.done_remove, atomic_read(&trace.done_invoked), > - atomic_read(&trace.rcu_try_flip_1), > - atomic_read(&trace.rcu_try_flip_e1), > - trace.rcu_try_flip_i1, trace.rcu_try_flip_ie1, > - trace.rcu_try_flip_g1, > - trace.rcu_try_flip_a1, trace.rcu_try_flip_ae1, > + seq_printf(m, "ggp=%ld rcc=%ld\n", > + rcu_batches_completed(), > + trace.rcu_check_callbacks); > + > + seq_printf(m, "na=%ld nl=%ld wa=%ld wl=%ld da=%ld dl=%ld dr=%ld di=%d\n" > + "1=%d e1=%d i1=%ld ie1=%ld g1=%ld a1=%ld ae1=%ld a2=%ld\n" > + "z1=%ld ze1=%ld z2=%ld m1=%ld me1=%ld m2=%ld\n", > + trace.next_add, trace.next_length, > + trace.wait_add, trace.wait_length, > + trace.done_add, trace.done_length, > + trace.done_remove, atomic_read(&trace.done_invoked), > + atomic_read(&trace.rcu_try_flip_1), > + atomic_read(&trace.rcu_try_flip_e1), > + trace.rcu_try_flip_i1, trace.rcu_try_flip_ie1, > + trace.rcu_try_flip_g1, > + trace.rcu_try_flip_a1, trace.rcu_try_flip_ae1, > trace.rcu_try_flip_a2, > - trace.rcu_try_flip_z1, trace.rcu_try_flip_ze1, > + trace.rcu_try_flip_z1, trace.rcu_try_flip_ze1, > trace.rcu_try_flip_z2, > - trace.rcu_try_flip_m1, trace.rcu_try_flip_me1, > - trace.rcu_try_flip_m2); > - bcount = simple_read_from_buffer(buffer, count, ppos, > - rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); > - mutex_unlock(&rcupreempt_trace_mutex); > - return bcount; > + trace.rcu_try_flip_m1, trace.rcu_try_flip_me1, > + trace.rcu_try_flip_m2); > + > + return 0; > +} > + > +static int rcustats_open(struct inode *inode, struct file *file) > +{ > + return single_open(file, show_rcustats, NULL); > } > > -static ssize_t rcugp_read(struct file *filp, char __user *buffer, > - size_t count, loff_t *ppos) > +static ssize_t show_rcugp(struct seq_file *m, void *unused) > { > long oldgp = rcu_batches_completed(); > - ssize_t bcount; > > - mutex_lock(&rcupreempt_trace_mutex); > synchronize_rcu(); > - snprintf(rcupreempt_trace_buf, RCUPREEMPT_TRACE_BUF_SIZE, > - "oldggp=%ld newggp=%ld\n", oldgp, rcu_batches_completed()); > - bcount = simple_read_from_buffer(buffer, count, ppos, > - rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); > - mutex_unlock(&rcupreempt_trace_mutex); > - return bcount; > + seq_printf(m, "oldggp=%ld newggp=%ld\n", > + oldgp, rcu_batches_completed()); > + > + return 0; > } > > -static ssize_t rcuctrs_read(struct file *filp, char __user *buffer, > - size_t count, loff_t *ppos) > +static int rcugp_open(struct inode *inode, struct file *file) > +{ > + return single_open(file, show_rcugp, NULL); > +} > + > +static ssize_t show_rcuctrs(struct seq_file *m, void *unused) > { > - int cnt = 0; > int cpu; > int f = rcu_batches_completed() & 0x1; > - ssize_t bcount; > - > - mutex_lock(&rcupreempt_trace_mutex); > > - cnt += snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE, > - "CPU last cur F M\n"); > + seq_puts(m, "CPU last cur F M\n"); > for_each_online_cpu(cpu) { > long *flipctr = rcupreempt_flipctr(cpu); > - cnt += snprintf(&rcupreempt_trace_buf[cnt], > - RCUPREEMPT_TRACE_BUF_SIZE - cnt, > - "%3d %4ld %3ld %d %d\n", > - cpu, > - flipctr[!f], > - flipctr[f], > - rcupreempt_flip_flag(cpu), > - rcupreempt_mb_flag(cpu)); > + seq_printf(m, "%3d %4ld %3ld %d %d\n", > + cpu, > + flipctr[!f], > + flipctr[f], > + rcupreempt_flip_flag(cpu), > + rcupreempt_mb_flag(cpu)); > } > - cnt += snprintf(&rcupreempt_trace_buf[cnt], > - RCUPREEMPT_TRACE_BUF_SIZE - cnt, > - "ggp = %ld, state = %s\n", > - rcu_batches_completed(), > - rcupreempt_try_flip_state_name()); > - cnt += snprintf(&rcupreempt_trace_buf[cnt], > - RCUPREEMPT_TRACE_BUF_SIZE - cnt, > - "\n"); > - bcount = simple_read_from_buffer(buffer, count, ppos, > - rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); > - mutex_unlock(&rcupreempt_trace_mutex); > - return bcount; > + seq_printf(m, "ggp = %ld, state = %s\n", > + rcu_batches_completed(), > + rcupreempt_try_flip_state_name()); > + > + return 0; > +} > + > +static int rcuctrs_open(struct inode *inode, struct file *file) > +{ > + return single_open(file, show_rcuctrs, NULL); > } > > static struct file_operations rcustats_fops = { > .owner = THIS_MODULE, > - .read = rcustats_read, > + .open = rcustats_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = single_release, > }; > > static struct file_operations rcugp_fops = { > .owner = THIS_MODULE, > - .read = rcugp_read, > + .open = rcugp_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = single_release, > }; > > static struct file_operations rcuctrs_fops = { > .owner = THIS_MODULE, > - .read = rcuctrs_read, > + .open = rcuctrs_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = single_release, > }; > > static struct dentry *rcudir, *statdir, *ctrsdir, *gpdir; > @@ -308,16 +301,7 @@ out: > > static int __init rcupreempt_trace_init(void) > { > - int ret; > - > - mutex_init(&rcupreempt_trace_mutex); > - rcupreempt_trace_buf = kmalloc(RCUPREEMPT_TRACE_BUF_SIZE, GFP_KERNEL); > - if (!rcupreempt_trace_buf) > - return 1; > - ret = rcupreempt_debugfs_init(); > - if (ret) > - kfree(rcupreempt_trace_buf); > - return ret; > + return rcupreempt_debugfs_init(); > } > > static void __exit rcupreempt_trace_cleanup(void) > @@ -326,7 +310,6 @@ static void __exit rcupreempt_trace_cleanup(void) > debugfs_remove(gpdir); > debugfs_remove(ctrsdir); > debugfs_remove(rcudir); > - kfree(rcupreempt_trace_buf); > } > > > -- > 1.5.4.rc3 >