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author | Mahendran Ganesh <opensource.ganesh@gmail.com> | 2018-04-25 18:59:31 +0800 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2018-05-10 11:36:46 +0200 |
commit | 00ee22c28915d111ba415750a3311d7678fd1206 (patch) | |
tree | 97f54410d8c5ffe5709d6a8a34dea7d381d70314 /drivers/base/power | |
parent | 7f817ba942940df382de085f9b830f77411562f2 (diff) | |
download | linux-stable-00ee22c28915d111ba415750a3311d7678fd1206.tar.gz linux-stable-00ee22c28915d111ba415750a3311d7678fd1206.tar.bz2 linux-stable-00ee22c28915d111ba415750a3311d7678fd1206.zip |
PM / wakeup: Use seq_open() to show wakeup stats
single_open() interface requires that the whole output must
fit into a single buffer. This will lead to timeout when
system memory is not in a good situation.
This patch use seq_open() to show wakeup stats. This method
need only one page, so timeout will not be observed.
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/base/power')
-rw-r--r-- | drivers/base/power/wakeup.c | 75 |
1 files changed, 59 insertions, 16 deletions
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c index ea01621ed769..5872705432f8 100644 --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -1029,32 +1029,75 @@ static int print_wakeup_source_stats(struct seq_file *m, return 0; } -/** - * wakeup_sources_stats_show - Print wakeup sources statistics information. - * @m: seq_file to print the statistics into. - */ -static int wakeup_sources_stats_show(struct seq_file *m, void *unused) +static void *wakeup_sources_stats_seq_start(struct seq_file *m, + loff_t *pos) { struct wakeup_source *ws; - int srcuidx; + loff_t n = *pos; + int *srcuidx = m->private; - seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t" - "expire_count\tactive_since\ttotal_time\tmax_time\t" - "last_change\tprevent_suspend_time\n"); + if (n == 0) { + seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t" + "expire_count\tactive_since\ttotal_time\tmax_time\t" + "last_change\tprevent_suspend_time\n"); + } - srcuidx = srcu_read_lock(&wakeup_srcu); - list_for_each_entry_rcu(ws, &wakeup_sources, entry) - print_wakeup_source_stats(m, ws); - srcu_read_unlock(&wakeup_srcu, srcuidx); + *srcuidx = srcu_read_lock(&wakeup_srcu); + list_for_each_entry_rcu(ws, &wakeup_sources, entry) { + if (n-- <= 0) + return ws; + } + + return NULL; +} + +static void *wakeup_sources_stats_seq_next(struct seq_file *m, + void *v, loff_t *pos) +{ + struct wakeup_source *ws = v; + struct wakeup_source *next_ws = NULL; + + ++(*pos); - print_wakeup_source_stats(m, &deleted_ws); + list_for_each_entry_continue_rcu(ws, &wakeup_sources, entry) { + next_ws = ws; + break; + } + + return next_ws; +} + +static void wakeup_sources_stats_seq_stop(struct seq_file *m, void *v) +{ + int *srcuidx = m->private; + + srcu_read_unlock(&wakeup_srcu, *srcuidx); +} + +/** + * wakeup_sources_stats_seq_show - Print wakeup sources statistics information. + * @m: seq_file to print the statistics into. + * @v: wakeup_source of each iteration + */ +static int wakeup_sources_stats_seq_show(struct seq_file *m, void *v) +{ + struct wakeup_source *ws = v; + + print_wakeup_source_stats(m, ws); return 0; } +static const struct seq_operations wakeup_sources_stats_seq_ops = { + .start = wakeup_sources_stats_seq_start, + .next = wakeup_sources_stats_seq_next, + .stop = wakeup_sources_stats_seq_stop, + .show = wakeup_sources_stats_seq_show, +}; + static int wakeup_sources_stats_open(struct inode *inode, struct file *file) { - return single_open(file, wakeup_sources_stats_show, NULL); + return seq_open_private(file, &wakeup_sources_stats_seq_ops, sizeof(int)); } static const struct file_operations wakeup_sources_stats_fops = { @@ -1062,7 +1105,7 @@ static const struct file_operations wakeup_sources_stats_fops = { .open = wakeup_sources_stats_open, .read = seq_read, .llseek = seq_lseek, - .release = single_release, + .release = seq_release_private, }; static int __init wakeup_sources_debugfs_init(void) |