Messages in this thread Patch in this message | | | Date | Sat, 10 Jan 2009 15:48:46 +0800 | From | Li Zefan <> | Subject | [PATCH] rcu: convert rcupreempt trace to seq file |
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Impact: also fix a bug in show_rcustats()
Use seq file for simplification, and the global buffer and mutex can be removed.
While doing this, I found rcustats will never show 'ggp' and 'rcc' fields due to a bug in show_rcustats().
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> --- 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 <linux/percpu.h> #include <linux/notifier.h> #include <linux/cpu.h> -#include <linux/mutex.h> #include <linux/rcupreempt_trace.h> #include <linux/debugfs.h> - -static struct mutex rcupreempt_trace_mutex; -static char *rcupreempt_trace_buf; -#define RCUPREEMPT_TRACE_BUF_SIZE 4096 +#include <linux/seq_file.h> 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
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