linux-kernel - Re: [Xen-devel] [PATCH RFC 00/12] xen-block: indirect descriptors

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <512F4323.50607@citrix.com>
Date:	Thu, 28 Feb 2013 12:44:35 +0100
From:	Roger Pau Monné <roger.pau@...rix.com>
To:	Jan Beulich <JBeulich@...e.com>
CC:	"xen-devel@...ts.xen.org" <xen-devel@...ts.xen.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [Xen-devel] [PATCH RFC 00/12] xen-block: indirect descriptors

On 28/02/13 12:35, Jan Beulich wrote:
>>>> On 28.02.13 at 12:25, Roger Pau Monné<roger.pau@...rix.com> wrote:
>> This is the expanded graph that also contains indirect descriptors
>> without persistent grants:
>>
>> http://xenbits.xen.org/people/royger/plot_indirect_nopers.png 
> 
> Thanks. Interesting - this suggests an unexpectedly high hit rate.

This graph is using the default values, so we are persistently mapping
1024 grants of the possible 2080 that could be used by blkfront ((64
segments + 1 indirect gref) * 32 = 2080).

blkfront stores grants using a stack, so it should try to reuse the same
grants as much as possible. On the other hand, blkback cleans unused
grants periodically, to try to have the most commonly used blkfront
grants mapped.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/