lkml.org 
[lkml]   [2018]   [Mar]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v2] PM / wakeup: use seq_open() to show wakeup stats
On Fri, Mar 30, 2018 at 12:25 PM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote:
> On Monday, March 5, 2018 9:47:46 AM CEST Ganesh Mahendran wrote:
>> 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>
>> ----
>> v2: use srcu_read_lock instead of rcu_read_lock
>> ---
>> drivers/base/power/wakeup.c | 77 +++++++++++++++++++++++++++++++++++----------
>> 1 file changed, 61 insertions(+), 16 deletions(-)
>>
>> diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
>> index ea01621..3bcab7d 100644
>> --- a/drivers/base/power/wakeup.c
>> +++ b/drivers/base/power/wakeup.c
>> @@ -1029,32 +1029,77 @@ 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)
>> + continue;
>> + goto out;
>> + }
>> + ws = NULL;
>> +out:
>> + return ws;
>> +}
>
> Please clean up the above at least.
>
> If I'm not mistaken, you don't need the label and the goto here.

The continue is also not needed, if the test condition is inverted.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

\
 
 \ /
  Last update: 2018-03-30 13:01    [W:0.089 / U:0.996 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site