From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>,
Andres Salomon <dilinger@debian.org>,
pm list <linux-pm@lists.linux-foundation.org>,
Chris Ball <cjb@laptop.org>,
David Woodhouse <dwmw2@infradead.org>,
Oleg Nesterov <oleg@tv-sign.ru>
Subject: Re: [RFC][PATCH -mm 2/2] Freezer: Use wait queue instead of busy looping
Date: Tue, 31 Jul 2007 12:17:59 +0200 [thread overview]
Message-ID: <200707311218.00512.rjw@sisk.pl> (raw)
In-Reply-To: <20070731100031.GA3462@elf.ucw.cz>
On Tuesday, 31 July 2007 12:00, Pavel Machek wrote:
> Hi!
>
> > > Ok, could we just do schedule_timeout(HZ/10) or something, but when we
> > > _know_ we woke someone, wakeup() that task? No new variables, keep
> > > existing logic.
> >
> > The logic doesn't change that much. :-)
> >
> > > That should still get most of the benefits, and be two liner, no?
> >
> > Well, I think we can avoid using refrigerator_called, if this is a problem, but
> > the patch won't be a two liner.
>
> Sure? The current process is ineffective because it polls. If we add
> schedule_timeout(HZ/10), we'll have still correct freezer (and it will
> not waste power any more), but it will delay freezing by HZ/20 on
> average.
>
> If we add wakeup() at strategic place, we should get rid of that delay...
But we'll need to know what to wake up ...
Greetings,
Rafael
--
"Premature optimization is the root of all evil." - Donald Knuth
next prev parent reply other threads:[~2007-07-31 10:17 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-25 12:01 [RFC][PATCH -mm 0/2] Freezer: Use wait queue instead of busy looping Rafael J. Wysocki
2007-07-25 12:03 ` [RFC][PATCH -mm 1/2] Freezer: Be more verbose Rafael J. Wysocki
2007-07-25 12:27 ` Pavel Machek
2007-07-25 12:09 ` [RFC][PATCH -mm 2/2] Freezer: Use wait queue instead of busy looping Rafael J. Wysocki
2007-07-25 12:28 ` Pavel Machek
2007-07-25 12:55 ` Rafael J. Wysocki
2007-07-25 13:29 ` Oleg Nesterov
2007-07-25 14:03 ` Rafael J. Wysocki
2007-07-25 14:24 ` Oleg Nesterov
2007-07-26 12:24 ` Rafael J. Wysocki
2007-07-26 12:43 ` Rafael J. Wysocki
2007-07-31 8:01 ` Pavel Machek
2007-07-31 9:39 ` Rafael J. Wysocki
2007-07-31 10:00 ` Pavel Machek
2007-07-31 10:17 ` Rafael J. Wysocki [this message]
2007-07-31 10:08 ` Rafael J. Wysocki
2007-07-31 10:02 ` Pavel Machek
2007-07-31 22:25 ` [RFC][PATCH -mm 0/3] Freezer: Use wait queue instead of busy looping (updated) Rafael J. Wysocki
2007-07-31 22:26 ` [RFC][PATCH -mm 1/3] Freezer: Use wait queue instead of busy looping Rafael J. Wysocki
2007-08-01 7:59 ` Pavel Machek
2007-07-31 22:28 ` [RFC][PATCH -mm 2/3] Freezer: Measure the time of freezing tasks Rafael J. Wysocki
2007-08-01 8:28 ` Pavel Machek
2007-07-31 22:29 ` [RFC][PATCH -mm 3/3] Freezer: Replace the timeout Rafael J. Wysocki
2007-08-01 8:31 ` Pavel Machek
2007-08-01 10:43 ` Rafael J. Wysocki
2007-08-05 21:37 ` Pavel Machek
2007-08-05 22:38 ` Rafael J. Wysocki
2007-08-05 22:53 ` Pavel Machek
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=200707311218.00512.rjw@sisk.pl \
--to=rjw@sisk.pl \
--cc=cjb@laptop.org \
--cc=dilinger@debian.org \
--cc=dwmw2@infradead.org \
--cc=linux-pm@lists.linux-foundation.org \
--cc=nigel@nigel.suspend2.net \
--cc=oleg@tv-sign.ru \
--cc=pavel@ucw.cz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox