lkml.org 
[lkml]   [2014]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [RFC v2 0/5] Non-blockling buffered fs read (page cache only)
Date
Jonathan Corbet <corbet@lwn.net> writes:

> On Fri, 19 Sep 2014 13:33:14 -0400
> Milosz Tanski <milosz@adfin.com> wrote:
>
>> > - Non-blocking I/O has long been supported with a well-understood set
>> > of operations - O_NONBLOCK and fcntl(). Why do we need a different
>> > mechanism here - one that's only understood in the context of
>> > buffered file I/O? I assume you didn't want to implement support
>> > for poll() and all that, but is that a good enough reason to add a
>> > new Linux-specific non-blocking I/O technique?
>>
>> I realized that I didn't answer this question well in my other long
>> email. O_NONBLOCK doesn't work on files under any commonly used OS,
>> and people have gotten use to this behavior so I doubt we could change
>> that without breaking a lot of folks applications.
>
> So I'm not contesting this, but I am genuinely curious: do you think
> there are applications out there requesting non-blocking behavior on
> regular files that will then break if they actually get non-blocking
> behavior? I don't suppose you have an example?

Hi, Jon,

Back when I tried to introduct O_NONBLOCK for regular files, the squid
proxy actually broke. Software that dealt with burning optical media
also broke. See my mail message here for more details:
https://lkml.org/lkml/2014/9/15/942

Cheers,
Jeff


\
 
 \ /
  Last update: 2014-09-22 17:01    [W:0.194 / U:0.184 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site