Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Fri, 30 Mar 2018 13:00:21 +0200 | Subject | Re: [PATCH v2] PM / wakeup: use seq_open() to show wakeup stats |
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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
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