linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Anton Blanchard <anton@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org, mikey@neuling.org, paulus@samba.org
Subject: Re: [PATCH 3/3] powerpc: POWER7 optimised copy_to_user/copy_from_user using VMX
Date: Fri, 17 Jun 2011 15:58:20 +1000	[thread overview]
Message-ID: <1308290300.32158.48.camel@pasglop> (raw)
In-Reply-To: <20110617045421.700411944@samba.org>

On Fri, 2011-06-17 at 14:54 +1000, Anton Blanchard wrote:
> plain text document attachment (power7_copy_tofrom_user)
> Implement a POWER7 optimised copy_to_user/copy_from_user using VMX.
> For large aligned copies this new loop is over 10% faster, and for
> large unaligned copies it is over 200% faster.
> 
> If we take a fault we fall back to the old version, this keeps
> things relatively simple and easy to verify.

Same re-entrancy comment as the other ones. preempt & interrupts...
Except here is worse since you may page fault and thus lose the vmx
state completely.

Cheers,
Ben.

      reply	other threads:[~2011-06-17  5:58 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-17  4:53 [PATCH 0/3] POWER7 optimised copy loops Anton Blanchard
2011-06-17  4:53 ` [PATCH 1/3] powerpc: POWER7 optimised copy_page using VMX Anton Blanchard
2011-06-17  5:16   ` Michael Neuling
2011-06-17  5:26     ` Anton Blanchard
2011-06-17  5:43   ` Benjamin Herrenschmidt
2011-06-17  5:53   ` Benjamin Herrenschmidt
2011-06-17 20:26     ` Segher Boessenkool
2011-06-17  4:54 ` [PATCH 2/3] powerpc: POWER7 optimised memcpy " Anton Blanchard
2011-06-17  5:57   ` Benjamin Herrenschmidt
2011-06-17  7:12   ` Gabriel Paubert
2011-06-17  9:02     ` David Laight
2011-06-17  4:54 ` [PATCH 3/3] powerpc: POWER7 optimised copy_to_user/copy_from_user " Anton Blanchard
2011-06-17  5:58   ` Benjamin Herrenschmidt [this message]

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=1308290300.32158.48.camel@pasglop \
    --to=benh@kernel.crashing.org \
    --cc=anton@samba.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mikey@neuling.org \
    --cc=paulus@samba.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).