From: Lev Makhlis <mlev@despammed.com>
To: linux-kernel@vger.kernel.org
Subject: PROC_BLOCK_SIZE in proc_info_read()
Date: Fri, 16 Jan 2004 23:10:17 -0500
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proc_info_read() (in fs/proc/base.c) uses this macro to limit the size
of a single read:

#define PROC_BLOCK_SIZE (3*1024)                /* 4K page size but our output 
routines use some slack for overruns */

It seems to me like it's a legacy from array_read() in 2.2.x and can be
safely removed.  Besides an outdated assumption about the page size,
the value is not passed down to (*proc_read)(), so it cannot guard
against any overruns, and serves no useful purpose.
Am I missing anything?

(This is not to be confused with PROC_BLOCK_SIZE in fs/proc/generic.c)

The reason it bothers me is that if you have a process with a really long
command line, then /proc/<pid>/cmdline "contains" up to PAGE_SIZE bytes,
but sys_read() only returns 3072, and needs to be called repeatedly.

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