public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Andi Kleen <ak@linux.intel.com>
To: "Rustad, Mark D" <mark.d.rustad@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>,
	"Kirsher, Jeffrey T" <jeffrey.t.kirsher@intel.com>,
	"<linux-kernel@vger.kernel.org>" <linux-kernel@vger.kernel.org>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	Netdev <netdev@vger.kernel.org>
Subject: Re: [PATCH 1/8] ixgbe: Out of line ixgbe_read/write_reg
Date: Mon, 19 May 2014 16:25:31 -0700	[thread overview]
Message-ID: <20140519232531.GJ19657@tassilo.jf.intel.com> (raw)
In-Reply-To: <7477F573-2AED-4D26-8D5F-DB80DFA7EDEF@intel.com>

On Mon, May 19, 2014 at 10:00:52PM +0000, Rustad, Mark D wrote:
> On May 16, 2014, at 2:43 PM, Andi Kleen <andi@firstfloor.org> wrote:
> 
> > From: Andi Kleen <ak@linux.intel.com>
> > 
> > ixgbe_read_reg and ixgbe_write_reg are frequently called and are very big
> > because they have complex error handling code.
> 
> Actually, this patch doesn't do anything to ixgbe_write_reg, which would almost certainly be very bad for performance, but instead changes ixgbe_write_reg64.

I doubt a few cycles around the write make a lot of difference for MMIO. MMIO is dominated
by other things.

> The latter is not in a performance-sensitive path, but is only called from one site, so there is little reason to take it out-of-line.

True I moved the wrong one.

ixgbe_write_reg                                    3305  (0.00%)  8     409  


> I already have a patch in queue to make ixgbe_read_reg out-of-line, because it does have a very costly memory footprint inline, as you have found.

Please move write_reg too.

-Andi

  reply	other threads:[~2014-05-19 23:32 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-16 21:43 Fix some common inline bloat Andi Kleen
2014-05-16 21:43 ` [PATCH 1/8] ixgbe: Out of line ixgbe_read/write_reg Andi Kleen
2014-05-19  9:14   ` David Laight
2014-05-19 22:00   ` Rustad, Mark D
2014-05-19 23:25     ` Andi Kleen [this message]
2014-05-20 17:06       ` Rustad, Mark D
2014-05-16 21:43 ` [PATCH 2/8] radeonfb: Out of line errata workarounds Andi Kleen
2014-05-16 21:43 ` [PATCH 3/8] list: Out of line INIT_LIST_HEAD and list_del Andi Kleen
2014-05-17  0:03   ` Dave Jones
2014-05-17  2:37     ` Andi Kleen
2014-05-17  0:03   ` Eric Dumazet
2014-05-16 21:43 ` [PATCH 4/8] e1000e: Out of line __ew32_prepare/__ew32 Andi Kleen
2014-05-17  3:23   ` Stephen Hemminger
2014-05-16 21:43 ` [PATCH 5/8] x86: Out of line get_dma_ops Andi Kleen
2014-05-16 21:43 ` [PATCH 6/8] ftrace: Out of line ftrace_trigger_soft_disabled Andi Kleen
2014-05-16 21:43 ` [PATCH 7/8] radeon: Out of line radeon_get_ib_value Andi Kleen
2014-05-20 16:16   ` Marek Olšák
2014-05-20 17:04     ` Andi Kleen
2014-05-20 18:14     ` Christian König
2014-05-16 21:43 ` [PATCH 8/8] Kbuild: add inline-account tool to find inline bloat Andi Kleen
2014-05-17  8:31   ` Sam Ravnborg
2014-05-17  9:36     ` Sam Ravnborg
2014-05-17 16:51       ` Andi Kleen

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=20140519232531.GJ19657@tassilo.jf.intel.com \
    --to=ak@linux.intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=andi@firstfloor.org \
    --cc=jeffrey.t.kirsher@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.d.rustad@intel.com \
    --cc=netdev@vger.kernel.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