From: Anupam Kapoor <anupam.kapoor@gmail.com>
To: "Valdis Klētnieks" <valdis.kletnieks@vt.edu>
Cc: Sumit Kumar <sumit686215@gmail.com>,
kernelnewbies <kernelnewbies@kernelnewbies.org>
Subject: Re: transfer physical memory page to swap disk
Date: Sun, 19 Jan 2020 10:55:44 +0000 [thread overview]
Message-ID: <CAEXHiZEBpf2KKFQ04wUkQqoW809aSq+2SMfuLfvEkJswzBnGZQ@mail.gmail.com> (raw)
In-Reply-To: <412530.1579360214@turing-police>
[-- Attachment #1.1: Type: text/plain, Size: 2048 bytes --]
On Wed, 15 Jan 2020 18:23:05 +0530, Anupam Kapoor said:
>> On Wed, 15 Jan 2020 at 6:02 PM Sumit Kumar <sumit686215@gmail.com> wrote:
>>> Does C/C++ provide any API / system call that enables user to force the
>>> application to transfer some its physical pages to swap disk ? If so,
is it
>>> also possible to obtain the least used page using some API ?
>> would madvise not serve your needs ?
> There's this word "force" in the question.
> The problem is that madvise() is *advice* to the kernel, not a strict
> guarantee. There's a difference between "If you need to move pages
> to disk, consider these pages first" and "Move them to disk now, whether
> you really wanted to or not".
ofcourse (afaik) there is no way for the application to force the
*kernel* to do something like this.
but if _all_ that is required is randomly unmapping some marked
application pages, _that_ can be naively 'done' by the application
itself :)
for example, have a list of unmappable pages and an unmapper thread
which does the unmapping for you (picking any element in the list
at random)
--
kind regards
anupam
In the beginning was the lambda, and the lambda was with Emacs, and Emacs
was the lambda.
On Sat, Jan 18, 2020 at 3:10 PM Valdis Klētnieks <valdis.kletnieks@vt.edu>
wrote:
> On Wed, 15 Jan 2020 18:23:05 +0530, Anupam Kapoor said:
> > On Wed, 15 Jan 2020 at 6:02 PM Sumit Kumar <sumit686215@gmail.com>
> wrote:
> > > Does C/C++ provide any API / system call that enables user to force the
> > > application to transfer some its physical pages to swap disk ? If so,
> is it
> > > also possible to obtain the least used page using some API ?
> > would madvise not serve your needs ?
>
> There's this word "force" in the question.
>
> The problem is that madvise() is *advice* to the kernel, not a strict
> guarantee. There's a difference between "If you need to move pages
> to disk, consider these pages first" and "Move them to disk now, whether
> you really wanted to or not".
>
>
[-- Attachment #1.2: Type: text/html, Size: 4081 bytes --]
[-- Attachment #2: Type: text/plain, Size: 170 bytes --]
_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
next prev parent reply other threads:[~2020-01-19 10:59 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-15 12:31 transfer physical memory page to swap disk Sumit Kumar
2020-01-15 12:42 ` aleix sanchis ramírez
2020-01-15 12:53 ` Anupam Kapoor
2020-01-18 15:10 ` Valdis Klētnieks
2020-01-19 10:01 ` Sumit Kumar
2020-01-19 10:55 ` Anupam Kapoor [this message]
2020-01-19 11:14 ` Valdis Klētnieks
2020-01-19 12:45 ` Anupam Kapoor
2020-01-19 13:18 ` Valdis Klētnieks
2020-01-19 16:01 ` Anupam Kapoor
2020-01-19 16:59 ` Bernd Petrovitsch
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=CAEXHiZEBpf2KKFQ04wUkQqoW809aSq+2SMfuLfvEkJswzBnGZQ@mail.gmail.com \
--to=anupam.kapoor@gmail.com \
--cc=kernelnewbies@kernelnewbies.org \
--cc=sumit686215@gmail.com \
--cc=valdis.kletnieks@vt.edu \
/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).