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From: Samuel Thibault <samuel.thibault@ens-lyon.org>
To: "Robert P. J. Day" <rpjday@crashcourse.ca>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: what's the purpose of MAXHOSTNAMELEN?
Date: Tue, 29 Dec 2009 20:28:27 +0100	[thread overview]
Message-ID: <20091229192827.GF4815@const> (raw)
In-Reply-To: <alpine.LFD.2.00.0912291416230.4967@localhost>

Robert P. J. Day, le Tue 29 Dec 2009 14:19:30 -0500, a écrit :
>   so lots of people define it but no one uses it.  it *is* exported to
> user space in /usr/include/asm/param.h, but i still have no idea what
> it's for in user space.  obsolete?

It's like all these *MAX* #defines: they are a bad way to express the
system limitations.  They are bad because they end up compiled-in, but
also because people understand them as "a typical allocation length" and
get lazy.  The typical example is PATH_MAX, which is #defined to 4096.
A _lot_ of applications thus keep allocating 4KB for all paths.

See
http://www.gnu.org/software/hurd/hurd/porting/guidelines.html#PATH_MAX_tt_MAX_PATH_tt_MAXPATHL

If you could drop it (would be completely POSIX-compliant), that'd be a
great service to GNU/Hurd porters, but I bet you'll also get a lot of
angry people.

Samuel

  reply	other threads:[~2009-12-29 19:35 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-12-29 19:19 what's the purpose of MAXHOSTNAMELEN? Robert P. J. Day
2009-12-29 19:28 ` Samuel Thibault [this message]
2009-12-29 19:40 ` Jeff Garzik
2009-12-29 19:56   ` Samuel Thibault
2009-12-29 20:20     ` Jeff Garzik
2009-12-29 20:26       ` Samuel Thibault
2009-12-29 21:00       ` Vikram Dhillon
2009-12-29 20:13   ` Robert P. J. Day

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