mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: "CHADHA,VINEET" <vineet@ufl.edu>
To: Arjan van de Ven <arjan@infradead.org>, "CHADHA,VINEET" <vineet@ufl.edu>
Cc: nickpiggin@yahoo.com.au, linux-kernel@vger.kernel.org
Subject: Re: TLB evaluation for Linux
Date: Tue, 2 Sep 2008 10:59:25 -0400 (EDT)	[thread overview]
Message-ID: <960293705.209651220367565443.JavaMail.osg@osgjas01.cns.ufl.edu> (raw)


On Tue Sep 02 09:43:53 EDT 2008, Arjan van de Ven 
<arjan@infradead.org> wrote:

> On Tue, 2 Sep 2008 00:12:03 -0400 (EDT)
> "CHADHA,VINEET" <vineet@ufl.edu> wrote:
> 

> note that linux only does an ipi to processors that actually are
> currently running a thread of the same program (or a kernel 
> thread).
> Old versions didn't do this (they also IPI'd idle processors), 
> but
> on modern cpus and modern kernels that's not supposed to happen 
> anymore
> (the C-states that flush the tlb anyway now do the kernel side
> bookkeeping as well to avoid the wakeup+useless flush)

Interesting to know about it.

> one of the problems is that invlpg is rather expensive; in 
> long-ago
> experiments the threshold was like around a handful of pages 
> already.
> At that point.. all the bookkeeping isn't likely to be a win.
> Esp since a tlb refill on x86 is quite cheap.

Yeah that is possible. Do you have link to any published work ? It 
would be still interesting to characterize and  compare behavior 
for new workloads scenarios such as virtual machines.


             reply	other threads:[~2008-09-02 14:59 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-09-02 14:59 CHADHA,VINEET [this message]
2008-09-02 15:38 ` Arjan van de Ven
  -- strict thread matches above, loose matches on Subject: below --
2008-09-02 16:14 CHADHA,VINEET
2008-09-02 14:36 CHADHA,VINEET
2008-09-02  4:12 CHADHA,VINEET
2008-09-02  4:39 ` Nick Piggin
2008-09-02  6:31 ` Andi Kleen
2008-09-02 13:43 ` Arjan van de Ven

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=960293705.209651220367565443.JavaMail.osg@osgjas01.cns.ufl.edu \
    --to=vineet@ufl.edu \
    --cc=arjan@infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nickpiggin@yahoo.com.au \
    /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

all inboxes | Powered by JetHome®