[lkml]   [2010]   [Mar]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: O_NONBLOCK is NOOP on block devices
Hi Jeff,

> I guess I should note that I've suggested nonblocking I/O for files
> before:
> I'll also note that enabling such a patch broke apps that accessed cd
> burners, for example, since O_NONBLOCK had some preexisting semantics
> there that I fail to recall.

Sounds like nonblocking read/write calls are strongly tied to threads
instead of state related to a file descriptor. I haven't poked around
in there, but perhaps the current linux io architecture is just too
set in stone to design an efficient non blocking mechanism. It would
be a shame not to fix it simply because some broken apps depend upon
blocking behavior when they have been explicitly specifying O_NONBLOCK
via open or fcntl.

At least for now we can describe it's actual behavior in the man
pages; I will be submitting a man page patch for consideration later

- Mike

 \ /
  Last update: 2010-03-05 20:59    [W:0.142 / U:0.820 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site