public inbox for netdev@vger.kernel.org
 help / color / mirror / Atom feed
From: David Miller <davem@davemloft.net>
To: adobriyan@gmail.com
Cc: steffen.klassert@secunet.com, herbert@gondor.apana.org.au,
	netdev@vger.kernel.org
Subject: Re: [PATCH 3/4] flowcache: make struct flow_cache_percpu::hash_rnd_recalc bool
Date: Tue, 21 Mar 2017 19:09:48 -0700 (PDT)	[thread overview]
Message-ID: <20170321.190948.1404708055619408272.davem@davemloft.net> (raw)
In-Reply-To: <20170319222743.GC17015@avx2>

From: Alexey Dobriyan <adobriyan@gmail.com>
Date: Mon, 20 Mar 2017 01:27:43 +0300

> ->hash_rnd_recalc is only used in boolean context.
> 
> Space savings on x86_64 come from the fact that "MOV rm8, imm8" is
> shorter than "MOV rm32, imm32" by at least 3 bytes.
> 
> 	add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-10 (-10)
> 	function                                     old     new   delta
> 	flow_cache_new_hashrnd                       166     163      -3
> 	flow_cache_cpu_up_prep                       171     168      -3
> 	flow_cache_lookup                           1148    1144      -4
> 	Total: Before=170822872, After=170822862, chg -0.00%
> 
> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>

I agree with Eric Dumazet that we might have atomicity issues in the
future because of this change.

Why don't you drop this and resubmit just the other 3 patches which
seem to be much less controversial?

Thanks.

  parent reply	other threads:[~2017-03-22  2:09 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-19 22:27 [PATCH 3/4] flowcache: make struct flow_cache_percpu::hash_rnd_recalc bool Alexey Dobriyan
2017-03-19 23:11 ` Eric Dumazet
2017-03-22  2:09 ` David Miller [this message]
2017-03-22 10:38   ` Alexey Dobriyan

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=20170321.190948.1404708055619408272.davem@davemloft.net \
    --to=davem@davemloft.net \
    --cc=adobriyan@gmail.com \
    --cc=herbert@gondor.apana.org.au \
    --cc=netdev@vger.kernel.org \
    --cc=steffen.klassert@secunet.com \
    /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