public inbox for util-linux@vger.kernel.org
 help / color / mirror / Atom feed
From: Karel Zak <kzak@redhat.com>
To: Sami Kerola <kerolasa@iki.fi>
Cc: util-linux@vger.kernel.org
Subject: Re: [PATCH] ul: enhance command performance
Date: Mon, 1 Jul 2013 14:05:15 +0200	[thread overview]
Message-ID: <20130701120515.GB1946@x2.net.home> (raw)
In-Reply-To: <1372581840-18966-1-git-send-email-kerolasa@iki.fi>

On Sun, Jun 30, 2013 at 09:44:00AM +0100, Sami Kerola wrote:
> Avoid reseting, time after time, the memory which was not used.  Effect
> of the change is below in before and after timings.
> 
> $ time ./ul </etc/services >/dev/null
> real    0m0.320s
> user    0m0.307s
> sys     0m0.010s
> 
> $ time ./ul </etc/services >/dev/null
> real    0m0.068s
> user    0m0.050s
> sys     0m0.017s

 Good catch :-)

> @@ -491,11 +491,11 @@ static void initbuf(void)
>  	if (obuf == NULL) {
>  		/* First time. */
>  		obuflen = BUFSIZ;
> -		obuf = xmalloc(sizeof(struct CHAR) * obuflen);
> +		obuf = xcalloc(obuflen, sizeof(struct CHAR));
>  	}
>  
    else

>  	/* assumes NORMAL == 0 */
> -	memset(obuf, 0, sizeof(struct CHAR) * obuflen);
> +	memset(obuf, 0, sizeof(struct CHAR) * col);

 I think 'maxcol' rather than col is more precise solution ;-) 

 Applied, thanks.

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com

      reply	other threads:[~2013-07-01 12:05 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-30  8:44 [PATCH] ul: enhance command performance Sami Kerola
2013-07-01 12:05 ` Karel Zak [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=20130701120515.GB1946@x2.net.home \
    --to=kzak@redhat.com \
    --cc=kerolasa@iki.fi \
    --cc=util-linux@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