From: Keir Fraser <keir.xen@gmail.com>
To: Dan Magenheimer <dan.magenheimer@oracle.com>,
Jan Beulich <JBeulich@suse.com>
Cc: TimDeegan <tim@xen.org>, Olaf Hering <olaf@aepfle.de>,
IanCampbell <Ian.Campbell@citrix.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
George Dunlap <George.Dunlap@eu.citrix.com>,
Ian Jackson <Ian.Jackson@eu.citrix.com>,
George Shuklin <george.shuklin@gmail.com>,
xen-devel@lists.xen.org, DarioFaggioli <raistlin@linux.it>,
Kurt Hackel <kurt.hackel@oracle.com>,
Zhigang Wang <zhigang.x.wang@oracle.com>
Subject: Re: Proposed new "memory capacity claim" hypercall/feature
Date: Thu, 08 Nov 2012 22:32:32 +0000 [thread overview]
Message-ID: <CCC1E380.444D7%keir.xen@gmail.com> (raw)
In-Reply-To: <563639fd-fc13-49cd-88cf-431244534c2f@default>
On 08/11/2012 19:16, "Dan Magenheimer" <dan.magenheimer@oracle.com> wrote:
>> Yes, this clearly prohibits unlimited batches. But not being able to
>> schedule should be less restrictive than not being able to run
>> softirqs, so I'd still put under question whether the limit shouldn't
>> be bumped.
>
> Wait, please define unlimited.
>
> I think we are in agreement from previous discussion that, to solve
> the TOCTOU race, the heap_lock must be held for the entire allocation
> for a domain creation. True?
It's pretty obvious that this isn't going to be possible in the general
case. E.g., a 40G domain being created out of 4k pages (eg. Because memory
is fragmented) is going to be at least 40G/4k == 10M heap operations. Say
each takes 10ns, which would be quick, we're talking 100ms of cpu work.
Holding a lock that long can't be recommended really.
-- Keir
next prev parent reply other threads:[~2012-11-08 22:32 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-29 17:06 Proposed new "memory capacity claim" hypercall/feature Dan Magenheimer
2012-10-29 18:24 ` Keir Fraser
2012-10-29 21:08 ` Dan Magenheimer
2012-10-29 22:22 ` Keir Fraser
2012-10-29 23:03 ` Dan Magenheimer
2012-10-29 23:17 ` Keir Fraser
2012-10-30 15:13 ` Dan Magenheimer
2012-10-30 14:43 ` Keir Fraser
2012-10-30 16:33 ` Dan Magenheimer
2012-10-30 9:11 ` George Dunlap
2012-10-30 16:13 ` Dan Magenheimer
2012-10-29 22:35 ` Tim Deegan
2012-10-29 23:21 ` Dan Magenheimer
2012-10-30 8:13 ` Tim Deegan
2012-10-30 15:26 ` Dan Magenheimer
2012-10-30 8:29 ` Jan Beulich
2012-10-30 15:43 ` Dan Magenheimer
2012-10-30 16:04 ` Jan Beulich
2012-10-30 17:13 ` Dan Magenheimer
2012-10-31 8:14 ` Jan Beulich
2012-10-31 16:04 ` Dan Magenheimer
2012-10-31 16:19 ` Jan Beulich
2012-10-31 16:51 ` Dan Magenheimer
2012-11-02 9:01 ` Jan Beulich
2012-11-02 9:30 ` Keir Fraser
2012-11-04 19:43 ` Dan Magenheimer
2012-11-04 20:35 ` Tim Deegan
2012-11-05 0:23 ` Dan Magenheimer
2012-11-05 10:29 ` Ian Campbell
2012-11-05 14:54 ` Dan Magenheimer
2012-11-05 22:24 ` Ian Campbell
2012-11-05 22:58 ` Zhigang Wang
2012-11-05 22:58 ` Dan Magenheimer
2012-11-06 13:23 ` Ian Campbell
2012-11-05 22:33 ` Dan Magenheimer
2012-11-06 10:49 ` Jan Beulich
2012-11-05 9:16 ` Jan Beulich
2012-11-07 22:17 ` Dan Magenheimer
2012-11-08 7:36 ` Keir Fraser
2012-11-08 10:11 ` Ian Jackson
2012-11-08 10:57 ` Keir Fraser
2012-11-08 21:45 ` Dan Magenheimer
2012-11-12 11:03 ` Ian Jackson
2012-11-08 8:00 ` Jan Beulich
2012-11-08 8:18 ` Keir Fraser
2012-11-08 8:54 ` Jan Beulich
2012-11-08 9:12 ` Keir Fraser
2012-11-08 9:47 ` Jan Beulich
2012-11-08 10:50 ` Keir Fraser
2012-11-08 13:48 ` Jan Beulich
2012-11-08 19:16 ` Dan Magenheimer
2012-11-08 22:32 ` Keir Fraser [this message]
2012-11-09 8:47 ` Jan Beulich
2012-11-08 18:38 ` Dan Magenheimer
2012-11-05 17:14 ` George Dunlap
2012-11-05 18:21 ` Dan Magenheimer
2012-11-01 2:13 ` Dario Faggioli
2012-11-01 15:51 ` Dan Magenheimer
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=CCC1E380.444D7%keir.xen@gmail.com \
--to=keir.xen@gmail.com \
--cc=George.Dunlap@eu.citrix.com \
--cc=Ian.Campbell@citrix.com \
--cc=Ian.Jackson@eu.citrix.com \
--cc=JBeulich@suse.com \
--cc=dan.magenheimer@oracle.com \
--cc=george.shuklin@gmail.com \
--cc=konrad.wilk@oracle.com \
--cc=kurt.hackel@oracle.com \
--cc=olaf@aepfle.de \
--cc=raistlin@linux.it \
--cc=tim@xen.org \
--cc=xen-devel@lists.xen.org \
--cc=zhigang.x.wang@oracle.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.