From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: akpm@linux-foundation.org, mhocko@suse.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, gorcunov@virtuozzo.com
Subject: Re: [PATCH] ksm: React on changing "sleep_millisecs" parameter faster
Date: Tue, 11 Dec 2018 13:03:46 +0300 [thread overview]
Message-ID: <20181211100346.GE2342@uranus.lan> (raw)
In-Reply-To: <db19c148-b375-b6f2-dbf5-9e78f5e46c04@virtuozzo.com>
On Tue, Dec 11, 2018 at 12:23:11PM +0300, Kirill Tkhai wrote:
...
> > Kirill, can we rather reuse @ksm_thread variable from ksm_init
> > (by moving it to static file level variable).
>
> I've considered using it, but this is not looks good for me.
> The problem is ksm thread may be parked, or it even may fail
> to start. But at the same time, parallel writes to "sleep_millisecs"
> are possible. There is a place for races, so to use the local
> variable in ksm_init() (like we have at the moment) looks better
> for me. At the patch the mutex protects against any races.
>
> > Also wakening up
> > unconditionally on write looks somehow suspicious to me
> > though I don't have a precise argument against.
>
> The conditional wait requires one more wait_queue. This is
> the thing I tried to avoid. But. I also had doubts about
> this, so you are already the second person, who worries :)
> It looks like we really need to change this.
>
> How are you about something like the below?
I see. The code below looks a way better for me, thanks!
next prev parent reply other threads:[~2018-12-11 10:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-10 16:06 [PATCH] ksm: React on changing "sleep_millisecs" parameter faster Kirill Tkhai
2018-12-10 20:10 ` Cyrill Gorcunov
2018-12-11 9:23 ` Kirill Tkhai
2018-12-11 10:03 ` Cyrill Gorcunov [this message]
2018-12-11 10:26 ` [PATCH v2] " Kirill Tkhai
2018-12-11 11:13 ` Cyrill Gorcunov
2018-12-11 12:22 ` Kirill Tkhai
2018-12-11 12:34 ` Cyrill Gorcunov
2018-12-11 14:15 ` Kirill Tkhai
2018-12-11 15:11 ` [PATCH v3] " Kirill Tkhai
2018-12-11 15:19 ` Cyrill Gorcunov
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=20181211100346.GE2342@uranus.lan \
--to=gorcunov@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=gorcunov@virtuozzo.com \
--cc=ktkhai@virtuozzo.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
/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;
as well as URLs for NNTP newsgroup(s).