From: Ian Campbell <Ian.Campbell@citrix.com>
To: Tamas K Lengyel <tamas.lengyel@zentific.com>
Cc: wei.liu2@citrix.com, Tim Deegan <tim@xen.org>,
"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>,
Stefano Stabellini <stefano.stabellini@citrix.com>,
Daniel De Graaf <dgdegra@tycho.nsa.gov>
Subject: Re: [PATCH for-4.5 v11 0/9] Mem_event and mem_access for ARM
Date: Mon, 29 Sep 2014 16:21:36 +0100 [thread overview]
Message-ID: <1412004096.3801.28.camel@citrix.com> (raw)
In-Reply-To: <CAErYnsia_d9W_aeE6jfVnmAJf9QuF_hNdKEeToWnvbPcQ-_GfQ@mail.gmail.com>
On Mon, 2014-09-29 at 17:17 +0200, Tamas K Lengyel wrote:
>
> For example I think they would would have pretty clearly shown
> poor
> performance due to the copy to/from user changes in your
> previous
> iteration.
>
> Ian.
>
>
> You are probably right, but aren't the copy to/from helpers only used
> if the guest is issuing hypercalls? I mean, what would the hypervisor
> copy in/out of the guest during kernbench running in the guest? That
> doesn't really sound right to me.
Guests (and dom0 issue hypercalls as part of the PV ring protocols
(kicking evtchns, mapping and unmapping grant references, etc) and for a
variety of other things while they are running workloads. For almost all
of those operations some sort of argument struct normally needs to be
copied in/out (often both) of guest memory.
Ian.
next prev parent reply other threads:[~2014-09-29 15:21 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-29 11:36 [PATCH for-4.5 v11 0/9] Mem_event and mem_access for ARM Tamas K Lengyel
2014-09-29 11:36 ` [PATCH for-4.5 v11 1/9] xen/arm: p2m changes for mem_access support Tamas K Lengyel
2014-09-29 12:26 ` Julien Grall
2014-09-29 12:41 ` Tamas K Lengyel
2014-09-29 11:36 ` [PATCH for-4.5 v11 2/9] xen/arm: Implement domain_get_maximum_gpfn Tamas K Lengyel
2014-09-29 11:36 ` [PATCH for-4.5 v11 3/9] xen/arm: Add p2m_set_permission and p2m_shatter_page helpers Tamas K Lengyel
2014-09-29 11:36 ` [PATCH for-4.5 v11 4/9] xen/arm: Data abort exception (R/W) mem_events Tamas K Lengyel
2014-09-29 12:35 ` Julien Grall
2014-09-29 12:47 ` Tamas K Lengyel
2014-09-29 12:52 ` Julien Grall
2014-09-29 12:53 ` Julien Grall
2014-09-29 11:36 ` [PATCH for-4.5 v11 5/9] xen/arm: Allow hypervisor access to mem_access protected pages Tamas K Lengyel
2014-09-29 14:12 ` Julien Grall
2014-09-29 14:44 ` Tamas K Lengyel
2014-09-29 14:50 ` Julien Grall
2014-09-29 14:57 ` Tamas K Lengyel
2014-09-29 15:07 ` Julien Grall
2014-09-29 11:36 ` [PATCH for-4.5 v11 6/9] xen/arm: Instruction prefetch abort (X) mem_event handling Tamas K Lengyel
2014-09-29 14:13 ` Julien Grall
2014-09-29 11:36 ` [PATCH for-4.5 v11 7/9] xen/arm: Enable the compilation of mem_access and mem_event on ARM Tamas K Lengyel
2014-09-29 11:36 ` [PATCH for-4.5 v11 8/9] tools/libxc: Allocate magic page for mem access " Tamas K Lengyel
2014-09-29 11:36 ` [PATCH for-4.5 v11 9/9] tools/tests: Enable xen-access " Tamas K Lengyel
2014-09-29 14:16 ` Julien Grall
2014-09-29 12:17 ` [PATCH for-4.5 v11 0/9] Mem_event and mem_access for ARM Tamas K Lengyel
2014-09-29 13:37 ` Ian Campbell
2014-09-29 14:21 ` Tamas K Lengyel
2014-09-29 15:07 ` Ian Campbell
2014-09-29 15:17 ` Tamas K Lengyel
2014-09-29 15:21 ` Ian Campbell [this message]
2014-09-29 15:29 ` Tamas K Lengyel
2014-09-30 11:02 ` Stefano Stabellini
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=1412004096.3801.28.camel@citrix.com \
--to=ian.campbell@citrix.com \
--cc=dgdegra@tycho.nsa.gov \
--cc=stefano.stabellini@citrix.com \
--cc=tamas.lengyel@zentific.com \
--cc=tim@xen.org \
--cc=wei.liu2@citrix.com \
--cc=xen-devel@lists.xen.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 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.