From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752869AbYJ0F2u (ORCPT ); Mon, 27 Oct 2008 01:28:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751328AbYJ0F2m (ORCPT ); Mon, 27 Oct 2008 01:28:42 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.143]:46775 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751319AbYJ0F2l (ORCPT ); Mon, 27 Oct 2008 01:28:41 -0400 Date: Sun, 26 Oct 2008 14:59:30 -0700 From: "Paul E. McKenney" To: Lai Jiangshan Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, rjw@sisk.pl, dipankar@in.ibm.com, tglx@linuxtronix.de, andi@firstfloor.org Subject: Re: [PATCH] v3 rudimentary tracing for Classic RCU Message-ID: <20081026215930.GC6236@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20081007071544.GC20740@one.firstfloor.org> <20081007152629.GH6384@linux.vnet.ibm.com> <20081007154939.GN20740@one.firstfloor.org> <20081007163401.GJ6384@linux.vnet.ibm.com> <20081007210947.GP20740@one.firstfloor.org> <20081007212215.GN6384@linux.vnet.ibm.com> <20081009010846.GA10188@linux.vnet.ibm.com> <20081010034421.GA12449@linux.vnet.ibm.com> <20081013230914.GA27467@linux.vnet.ibm.com> <49005C09.6010805@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49005C09.6010805@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 Thu, Oct 23, 2008 at 07:12:09PM +0800, Lai Jiangshan wrote: > > trivial ported it to seq_file. > seq_file are very good for the output buffer. Thank you for putting this together!!! Looks good at first glance -- I will test it out. Thanx, Paul > Signed-off-by: Lai Jiangshan > --- > diff --git a/kernel/rcuclassic_trace.c b/kernel/rcuclassic_trace.c > index d19780b..f19217c > --- a/kernel/rcuclassic_trace.c > +++ b/kernel/rcuclassic_trace.c > @@ -23,157 +23,167 @@ > * Documentation/RCU > * > */ > -#include > -#include > -#include > -#include > -#include > #include > -#include > -#include > -#include > -#include > #include > -#include > -#include > -#include > -#include > -#include > -#include > #include > +#include > > -static DEFINE_MUTEX(rcuclassic_trace_mutex); > -static char *rcuclassic_trace_buf; > -#define RCUCLASSIC_TRACE_BUF_SIZE (128 * num_possible_cpus() + 100) > +static struct rcu_data *get_rcu_data_bh(int cpu) > +{ > + return &per_cpu(rcu_bh_data, cpu); > +} > > -static int print_one_rcu_data(struct rcu_data *rdp, char *buf, char *ebuf) > +static struct rcu_data *get_rcu_data(int cpu) > { > - int cnt = 0; > + return &per_cpu(rcu_data, cpu); > +} > > +static int show_rcu_data(struct seq_file *m, void *v) > +{ > + struct rcu_data *rdp = v; > if (!rdp->beenonline) > return 0; > - cnt += snprintf(&buf[cnt], ebuf - &buf[cnt], > - "%3d%cqb=%ld b=%ld pq=%d qsp=%d ql=%ld bl=%ld\n", > - rdp->cpu, cpu_is_offline(rdp->cpu) ? '!' : ' ', > - rdp->quiescbatch, rdp->batch, rdp->passed_quiesc, > - rdp->qs_pending, rdp->qlen, rdp->blimit); > - return cnt; > + > + seq_printf(m, "processor\t: %d", rdp->cpu); > + if (cpu_is_offline(rdp->cpu)) > + seq_puts(m, "!\n"); > + else > + seq_puts(m, "\n"); > + seq_printf(m, "quiescbatch\t: %ld\n", rdp->quiescbatch); > + seq_printf(m, "batch\t: %ld\n", rdp->batch); > + seq_printf(m, "passed_quiesc\t: %d\n", rdp->passed_quiesc); > + seq_printf(m, "qs_pending\t: %d\n", rdp->qs_pending); > + seq_printf(m, "qlen\t: %ld\n", rdp->qlen); > + seq_printf(m, "blimit\t: %ld\n", rdp->blimit); > + seq_puts(m, "\n\n"); > + return 0; > } > > -#define PRINT_RCU_DATA(name, buf, ebuf) \ > - do { \ > - int _p_r_d_i; \ > - \ > - for_each_possible_cpu(_p_r_d_i) \ > - (buf) += print_one_rcu_data(&per_cpu(name, _p_r_d_i), \ > - buf, ebuf); \ > - } while (0) > - > -static ssize_t rcudata_read(struct file *filp, char __user *buffer, > - size_t count, loff_t *ppos) > +static void *c_start(struct seq_file *m, loff_t *pos) > { > - ssize_t bcount; > - char *buf = rcuclassic_trace_buf; > - char *ebuf = &rcuclassic_trace_buf[RCUCLASSIC_TRACE_BUF_SIZE]; > - > - mutex_lock(&rcuclassic_trace_mutex); > - buf += snprintf(buf, ebuf - buf, "rcu:\n"); > - PRINT_RCU_DATA(rcu_data, buf, ebuf); > - buf += snprintf(buf, ebuf - buf, "rcu_bh:\n"); > - PRINT_RCU_DATA(rcu_bh_data, buf, ebuf); > - bcount = simple_read_from_buffer(buffer, count, ppos, > - rcuclassic_trace_buf, strlen(rcuclassic_trace_buf)); > - mutex_unlock(&rcuclassic_trace_mutex); > - return bcount; > + typedef struct rcu_data *(*get_data_func)(int); > + > + if (*pos == 0) /* just in case, cpu 0 is not the first */ > + *pos = first_cpu(cpu_possible_map); > + else > + *pos = next_cpu_nr(*pos - 1, cpu_possible_map); > + if ((*pos) < nr_cpu_ids) > + return ((get_data_func)m->private)(*pos); > + return NULL; > } > > -static int print_one_rcu_ctrlblk(struct rcu_ctrlblk *rcp, char *buf, char *ebuf) > +static void *c_next(struct seq_file *m, void *v, loff_t *pos) > { > - int cnt = 0; > - > - cnt += snprintf(&buf[cnt], ebuf - &buf[cnt], "cur=%ld completed=%ld " > - "pending=%ld s=%d\n\t", > - rcp->cur, rcp->completed, > - rcp->pending, rcp->signaled); > - cnt += cpulist_scnprintf(&buf[cnt], ebuf - &buf[cnt], rcp->cpumask); > - cnt += snprintf(&buf[cnt], ebuf - &buf[cnt], "\n"); > - return cnt; > + (*pos)++; > + return c_start(m, pos); > } > > -static ssize_t rcucb_read(struct file *filp, char __user *buffer, > - size_t count, loff_t *ppos) > +static void c_stop(struct seq_file *m, void *v) > { > - ssize_t bcount; > - char *buf = rcuclassic_trace_buf; > - char *ebuf = &rcuclassic_trace_buf[RCUCLASSIC_TRACE_BUF_SIZE]; > - > - mutex_lock(&rcuclassic_trace_mutex); > - buf += snprintf(buf, ebuf - buf, "rcu: "); > - buf += print_one_rcu_ctrlblk(&rcu_ctrlblk, buf, ebuf); > - buf += snprintf(buf, ebuf - buf, "rcu_bh: "); > - buf += print_one_rcu_ctrlblk(&rcu_bh_ctrlblk, buf, ebuf); > - buf += snprintf(buf, ebuf - buf, "online: "); > - buf += cpulist_scnprintf(buf, ebuf - buf, cpu_online_map); > - buf += snprintf(buf, ebuf - buf, "\n"); > - bcount = simple_read_from_buffer(buffer, count, ppos, > - rcuclassic_trace_buf, strlen(rcuclassic_trace_buf)); > - mutex_unlock(&rcuclassic_trace_mutex); > - return bcount; > } > > -static struct file_operations rcudata_fops = { > - .owner = THIS_MODULE, > - .read = rcudata_read, > +const struct seq_operations rcu_data_seq_op = { > + .start = c_start, > + .next = c_next, > + .stop = c_stop, > + .show = show_rcu_data, > }; > > +static int rcu_data_open(struct inode *inode, struct file *file) > +{ > + int ret = seq_open(file, &rcu_data_seq_op); > + if (ret) > + return ret; > + ((struct seq_file *)file->private_data)->private = inode->i_private; > + return 0; > +} > + > +static const struct file_operations rcu_data_fops = { > + .owner = THIS_MODULE, > + .open = rcu_data_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = seq_release, > +}; > + > +static void print_one_rcu_ctrlblk(struct seq_file *m, struct rcu_ctrlblk *rcp) > +{ > + seq_printf(m, "cur=%ld completed=%ld pending=%ld s=%d\n\t", > + rcp->cur, rcp->completed, rcp->pending, rcp->signaled); > + seq_cpumask(m, &rcp->cpumask); > + seq_puts(m, "\n"); > +} > + > +static int show_rcucb(struct seq_file *m, void *unused) > +{ > + seq_puts(m, "rcu: "); > + print_one_rcu_ctrlblk(m, &rcu_ctrlblk); > + seq_puts(m, "rcu_bh: "); > + print_one_rcu_ctrlblk(m, &rcu_bh_ctrlblk); > + seq_puts(m, "online: "); > + seq_cpumask(m, &cpu_online_map); > + seq_puts(m, "\n"); > + return 0; > +} > + > +static int rcucb_open(struct inode *inode, struct file *file) > +{ > + return single_open(file, show_rcucb, NULL); > +} > + > static struct file_operations rcucb_fops = { > - .owner = THIS_MODULE, > - .read = rcucb_read, > + .owner = THIS_MODULE, > + .open = rcucb_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = single_release, > }; > > -static struct dentry *rcudir, *datadir, *cbdir; > -static int rcuclassic_debugfs_init(void) > +static struct dentry *rcudir, *rcu_bh_data_file, *rcu_data_file, *rcucb_file; > + > +static int __init rcuclassic_trace_init(void) > { > rcudir = debugfs_create_dir("rcu", NULL); > if (!rcudir) > goto out; > - datadir = debugfs_create_file("rcudata", 0444, rcudir, > - NULL, &rcudata_fops); > - if (!datadir) > - goto free_out; > - cbdir = debugfs_create_file("rcucb", 0444, rcudir, NULL, &rcucb_fops); > - if (!cbdir) > - goto free_out; > + > + rcu_bh_data_file = debugfs_create_file("rcu_bh_data", 0444, rcudir, > + get_rcu_data_bh, &rcu_data_fops); > + if (!rcu_bh_data_file) > + goto out_rcudir; > + > + rcu_data_file = debugfs_create_file("rcu_data", 0444, rcudir, > + get_rcu_data, &rcu_data_fops); > + if (!rcu_data_file) > + goto out_rcudata_bh_file; > + > + rcucb_file = debugfs_create_file("rcucb", 0444, rcudir, > + NULL, &rcucb_fops); > + if (!rcucb_file) > + goto out_rcudata_file; > return 0; > -free_out: > - if (datadir) > - debugfs_remove(datadir); > + > +out_rcudata_file: > + debugfs_remove(rcu_data_file); > +out_rcudata_bh_file: > + debugfs_remove(rcu_bh_data_file); > +out_rcudir: > debugfs_remove(rcudir); > out: > return 1; > } > > -static int __init rcuclassic_trace_init(void) > -{ > - int ret; > - > - rcuclassic_trace_buf = kmalloc(RCUCLASSIC_TRACE_BUF_SIZE, GFP_KERNEL); > - if (!rcuclassic_trace_buf) > - return 1; > - ret = rcuclassic_debugfs_init(); > - if (ret) > - kfree(rcuclassic_trace_buf); > - return ret; > -} > - > static void __exit rcuclassic_trace_cleanup(void) > { > - debugfs_remove(datadir); > - debugfs_remove(cbdir); > + debugfs_remove(rcucb_file); > + debugfs_remove(rcu_data_file); > + debugfs_remove(rcu_bh_data_file); > debugfs_remove(rcudir); > - kfree(rcuclassic_trace_buf); > } > > - > module_init(rcuclassic_trace_init); > module_exit(rcuclassic_trace_cleanup); > + > +MODULE_AUTHOR("Paul E. McKenney"); > +MODULE_DESCRIPTION("Read-Copy Update tracing for classic implementation"); > +MODULE_LICENSE("GPL"); >