From: Alasdair G Kergon <agk@redhat.com>
To: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>,
Mikulas Patocka <mpatocka@redhat.com>,
"xinhui.pan" <xinhuix.pan@intel.com>,
linux-kernel@vger.kernel.org, agk@redhat.com, snitzer@redhat.com,
dm-devel@redhat.com, "Liu, ShuoX" <shuox.liu@intel.com>
Subject: Re: [dm-devel] [PATCH] md/dm-ioctl.c: optimize memory allocation in copy_params
Date: Tue, 22 Jul 2014 03:04:58 +0100 [thread overview]
Message-ID: <20140722020458.GE6822@agk-dp.fab.redhat.com> (raw)
In-Reply-To: <20140722012352.GD6822@agk-dp.fab.redhat.com>
On Tue, Jul 22, 2014 at 02:23:52AM +0100, Alasdair G Kergon wrote:
> Unanswered. Let's ask the same question in a different way:
A quick search for 'vold' returns:
https://android.googlesource.com/platform/system/vold/
and the code there requests a fixed 64K allocation to hold the names of
active volumes.
So unlike libdevmapper-based applications where a smaller allocation is
used at first and only extended if needed, Android just assumes that
64KB is enough for everyone.
So is your claim that:
1. This 64KB allocation for the brief duration of the ioctl to store the
names of active device-mapper volumes leads to memory problems?
[Mustn't the system *already* be in a bad state if this pushes it over
the limit?]
and
2. The systems on which this memory shortage occurs have so many volumes
(with long names?) that a smaller allocation would not suffice?
Alasdair
next prev parent reply other threads:[~2014-07-22 2:05 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-04 10:22 [PATCH] md/dm-ioctl.c: optimize memory allocation in copy_params xinhui.pan
2014-07-08 22:39 ` [dm-devel] " Mikulas Patocka
2014-07-09 2:01 ` Zhang, Yanmin
2014-07-09 3:37 ` xinhui.pan
2014-07-09 14:53 ` Mikulas Patocka
2014-07-22 1:02 ` Zhang, Yanmin
2014-07-22 1:23 ` Alasdair G Kergon
2014-07-22 2:04 ` Alasdair G Kergon [this message]
2014-07-23 3:15 ` Zhang, Yanmin
2014-07-23 3:06 ` Zhang, Yanmin
2014-07-23 12:16 ` Mikulas Patocka
2014-07-23 12:54 ` Alasdair G Kergon
2014-07-23 17:14 ` Mikulas Patocka
2014-07-24 5:53 ` Zhang, Yanmin
2014-07-23 12:39 ` Mikulas Patocka
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=20140722020458.GE6822@agk-dp.fab.redhat.com \
--to=agk@redhat.com \
--cc=dm-devel@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mpatocka@redhat.com \
--cc=shuox.liu@intel.com \
--cc=snitzer@redhat.com \
--cc=xinhuix.pan@intel.com \
--cc=yanmin_zhang@linux.intel.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).