From: Geert Uytterhoeven <geert@linux-m68k.org>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Ganesh Mahendran <opensource.ganesh@gmail.com>,
Pavel Machek <pavel@ucw.cz>, Len Brown <len.brown@intel.com>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Greg KH <gregkh@linuxfoundation.org>,
Linux PM list <linux-pm@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] PM / wakeup: use seq_open() to show wakeup stats
Date: Fri, 30 Mar 2018 13:00:21 +0200 [thread overview]
Message-ID: <CAMuHMdXqLmyJF6qhyzgnPeU=T0TyxDpsw1PD8BiYiSXCZeTz=g@mail.gmail.com> (raw)
In-Reply-To: <2654052.UvzeiuBsVA@aspire.rjw.lan>
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
next prev parent reply other threads:[~2018-03-30 11:00 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-05 8:47 [PATCH v2] PM / wakeup: use seq_open() to show wakeup stats Ganesh Mahendran
2018-03-12 5:33 ` Ganesh Mahendran
2018-03-13 16:39 ` Andy Shevchenko
2018-03-14 1:33 ` Ganesh Mahendran
2018-03-29 7:49 ` Ganesh Mahendran
2018-03-29 21:54 ` Rafael J. Wysocki
2018-03-30 10:25 ` Rafael J. Wysocki
2018-03-30 11:00 ` Geert Uytterhoeven [this message]
2018-04-02 1:33 ` Ganesh Mahendran
2018-04-02 6:46 ` Geert Uytterhoeven
2018-04-25 11:01 ` Ganesh Mahendran
2018-04-02 1:31 ` Ganesh Mahendran
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