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Date: Wed, 27 Apr 2011 06:18:44 +0300
From: Alexey Dobriyan <adobriyan@gmail.com>
To: Am??rico Wang <xiyou.wangcong@gmail.com>
Cc: Jidong Xiao <jidong.xiao@gmail.com>,
        Kernel development list <linux-kernel@vger.kernel.org>
Subject: Re: How to export information larger than PROC_BLOCK_SIZE via /proc
 file system?
Message-ID: <20110427031844.GA5595@p183>
References: <BANLkTinQJ6wzOR++c-OSiCkf=MjOU=y=1A@mail.gmail.com>
 <BANLkTik+9oz9fbeTwS4qd32ukw6uPHtrWA@mail.gmail.com>
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On Wed, Apr 27, 2011 at 11:00:32AM +0800, Am??rico Wang wrote:
> On Wed, Apr 27, 2011 at 8:54 AM, Jidong Xiao <jidong.xiao@gmail.com> wrote:
> > Hi,
> >
> > I am tracing some data inside the kernel, and I plan to export the
> > tracing data through /proc file system. I created a file under /proc
> > file system, and I use cat to display the tracing data. However, every
> > time there is only 3072 bytes data displayed, which is the size
> > defined by PROC_BLOCK_SIZE. And I wonder that how to export
> > information more than that limit? Judging from the function
> > fs/proc/generic.c/proc_file_read(), if the size returned by my
> > read_proc function is large than a PAGE_SIZE, then I will get a
> > KERN_ERR message which says "proc_file_read: Apparent buffer
> > overflow!". Any help would be appreciated!
> >
> 
> Why not switch to use debugfs?

Or use seq_file/proc_create.
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