RE: [PATCH] [2.5] Non-blocking write can block

["Hua Zhong" <hzhong@cisco.com>]

We ran into this problem here in an embedded environment. It causes
syslogd to hang and when this happens, everybody who talks to syslogd
hangs. Which means you may not even be able to login. In the end we used
exactly the same fix which seems to work.

I am curious to know the correct fix.

> On Wed, 4 Jun 2003, Christoph Hellwig wrote:
> > 
> > The else should be on the same line as the closing brace, else
> > the patch looks fine.
> 
> No no no, it's wrong.
> 
> If you do something like this, then you also have to teach "select()" 
> about this, otherwise you just get busy looping in applications.
> 
> In general, we shouldn't do this, unless somebody can show an 
> application 
> where it really matters. Taking internal kernel locking into 
> account for 
> "blockingness" easily gets quite complicated, and there is 
> seldom any real 
> point to it.
> 
> Remember: perfect is the enemy of good. I'll happily apply 
> the patch (if 
> it also updates the tty poll() functionality), _if_ there is some 
> real-world situation where it matters.
> 
> 		Linus
> 
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