From: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
To: Rafael Aquini <aquini@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
akpm@linux-foundation.org, hughd@google.com, shli@kernel.org,
kzak@redhat.com, jmoyer@redhat.com, riel@redhat.com,
lwoodman@redhat.com, mgorman@suse.de, kosaki.motohiro@gmail.com
Subject: Re: [RFC PATCH 02/02] swapon: add "cluster-discard" support
Date: Mon, 20 May 2013 21:02:43 -0400 [thread overview]
Message-ID: <519AC7B3.5060902@gmail.com> (raw)
In-Reply-To: <398ace0dd3ca1283372b3aad3fceeee59f6897d7.1369084886.git.aquini@redhat.com>
> +.B "\-c, \-\-cluster\-discard"
> +Swapping will discard clusters of swap pages in between freeing them
> +and re-writing to them, if the swap device supports that. This option
> +also implies the
> +.I \-d, \-\-discard
> +swapon flag.
I'm not sure this is good idea. Why can't we make these flags orthogonal?
> /* If true, don't complain if the device/file doesn't exist */
> static int ifexists;
> @@ -570,8 +574,11 @@ static int do_swapon(const char *orig_special, int prio,
> << SWAP_FLAG_PRIO_SHIFT);
> }
> #endif
> - if (fl_discard)
> + if (fl_discard) {
> flags |= SWAP_FLAG_DISCARD;
> + if (fl_discard > 1)
> + flags |= SWAP_FLAG_DISCARD_CLUSTER;
This is not enough, IMHO. When running this code on old kernel, swapon() return EINVAL.
At that time, we should fall back swapon(0x10000).
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2013-05-21 1:02 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-21 0:04 [RFC PATCH 00/02] swap: allowing a more flexible DISCARD policy Rafael Aquini
2013-05-21 0:04 ` [RFC PATCH 01/02] swap: discard while swapping only if SWAP_FLAG_DISCARD_CLUSTER Rafael Aquini
2013-05-21 0:55 ` KOSAKI Motohiro
2013-05-21 21:06 ` Rafael Aquini
2013-05-21 0:04 ` [RFC PATCH 02/02] swapon: add "cluster-discard" support Rafael Aquini
2013-05-21 1:02 ` KOSAKI Motohiro [this message]
2013-05-21 10:26 ` Karel Zak
2013-05-21 20:17 ` KOSAKI Motohiro
2013-05-21 21:13 ` Rafael Aquini
2013-05-21 22:01 ` KOSAKI Motohiro
2013-05-22 13:52 ` Jeff Moyer
2013-05-21 10:13 ` Karel Zak
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=519AC7B3.5060902@gmail.com \
--to=kosaki.motohiro@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=aquini@redhat.com \
--cc=hughd@google.com \
--cc=jmoyer@redhat.com \
--cc=kzak@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=lwoodman@redhat.com \
--cc=mgorman@suse.de \
--cc=riel@redhat.com \
--cc=shli@kernel.org \
/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).