Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 9 Apr 2011 20:36:25 +0000
From:      Alexander Best <arundel@freebsd.org>
To:        dieterbsd@engineer.com
Cc:        freebsd-hackers@freebsd.org
Subject:   Re: *printf(9) and PRINTF_BUFR_SIZE
Message-ID:  <20110409203625.GA50231@freebsd.org>
In-Reply-To: <8CDC50749BB9940-18FC-38C6@web-mmc-m02.sysops.aol.com>
References:  <8CDC50749BB9940-18FC-38C6@web-mmc-m02.sysops.aol.com>

next in thread | previous in thread | raw e-mail | index | archive | help
On Sat Apr  9 11, dieterbsd@engineer.com wrote:
> While working on other problems with *printf(9), log(9), etc.
> I stumbled upon:
> 
> options   PRINTF_BUFR_SIZE=128    # Prevent printf output being 
> interspersed.
> 
> Question 1: Am I correct in thinking that PRINTF_BUFR_SIZE is supposed
> to prevent this:
> 
>   ada2: 300.000MB/s transfuhub2: 3 ports with 3 removable, self powered
>   ers (SATA 2.x, UDMA6, PIO 8192bytes)
>   ada2: Command Queueing enabled
> 
> Question 2: Why is vprintf() the only function that does this buffering?
> As far as I can tell, the various functions that call kvprintf() 
> directly
> without going through vprintf() do not get buffered.  I'm thinking that
> kvprintf() would be a better place for the buffering.  Or would this 
> break
> something?

i remember this issue was discussed a few times before. you might want to
take a look at [1].

cheers.
alex

[1] http://docs.freebsd.org/cgi/mid.cgi?AANLkTinPhcc8Z_BdvoEQUv-ZXlHAYOTQJwlUQDVO8iJ9

> 
> 

-- 
a13x



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20110409203625.GA50231>