Messages in this thread Patch in this message | | | Date | Thu, 23 Oct 2008 19:12:09 +0800 | From | Lai Jiangshan <> | Subject | Re: [PATCH] v3 rudimentary tracing for Classic RCU |
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trivial ported it to seq_file. seq_file are very good for the output buffer.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> --- 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 <linux/types.h> -#include <linux/kernel.h> -#include <linux/init.h> -#include <linux/spinlock.h> -#include <linux/smp.h> #include <linux/rcupdate.h> -#include <linux/interrupt.h> -#include <linux/sched.h> -#include <asm/atomic.h> -#include <linux/bitops.h> #include <linux/module.h> -#include <linux/completion.h> -#include <linux/moduleparam.h> -#include <linux/percpu.h> -#include <linux/notifier.h> -#include <linux/cpu.h> -#include <linux/mutex.h> #include <linux/debugfs.h> +#include <linux/seq_file.h> -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");
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