All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Jan Beulich" <JBeulich@suse.com>
To: J Ahn <jeong.seob.ahn@gmail.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>
Subject: Re: How to handle TLB shootdown IPI on Xen
Date: Mon, 12 Aug 2013 09:36:31 +0100	[thread overview]
Message-ID: <5208BAAF02000078000EB097@nat28.tlf.novell.com> (raw)
In-Reply-To: <CAFgwMgoBxiektxmjMDGvE1W9fGthoiiY=Zt598c+g8+1QC+_rw@mail.gmail.com>

>>> On 11.08.13 at 18:22, J Ahn <jeong.seob.ahn@gmail.com> wrote:
> I am just wondering how to handle the TLB shootdown IPIs in Xen.
> Specifically, the guest will send the TLB shootdown IPI to remote CPUs if
> TLB synchronization between CPUs is required.
> 
> In this case, I guess the hypervisor intervention is required because it
> needs to route the interrupt to virtual CPUs of corresponding guest.
> However, Xen seems not to intercept the event because the number of IPIs
> from Xenperf is very low. Is this right?
> 
> I checked the number of IPIs is relatively high in guest OS when using 'cat
> /proc/interrupts'.
> I also checked the system does not invoke the '*invalidate_interrupt*'
> function located in *'arch/x86/smp.c*'.
> 
> If there is no need to intervene to deal with that, could anyone explain
> that how to maintain the consistent view of TLBs in the guest hosted by Xen?
> Otherwise, please let me know the handling TLB shootdown IPI code in Xen.

I'm getting the impression that you simply mix up physical IPIs (as
used by the hypervisor) and their virtualized counterparts (as used
by HVM guests).

Jan

  reply	other threads:[~2013-08-12  9:26 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-11 16:22 How to handle TLB shootdown IPI on Xen J Ahn
2013-08-12  8:36 ` Jan Beulich [this message]
2013-08-12 12:47   ` J Ahn
2013-08-12 13:29     ` Jan Beulich
2013-08-12 16:04       ` J Ahn
2013-08-12 16:24         ` Jan Beulich
2013-08-12 16:50           ` J Ahn
2013-08-13 10:16             ` Jan Beulich
2013-08-13 13:16               ` J Ahn

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=5208BAAF02000078000EB097@nat28.tlf.novell.com \
    --to=jbeulich@suse.com \
    --cc=jeong.seob.ahn@gmail.com \
    --cc=xen-devel@lists.xenproject.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.