Messages in this thread | | | From | Jeff Moyer <> | Date | Mon, 11 Oct 2004 14:58:59 -0400 | Subject | Re: [patch rfc] towards supporting O_NONBLOCK on regular files |
| |
==> Regarding Re: [patch rfc] towards supporting O_NONBLOCK on regular files; "Stephen C. Tweedie" <sct@redhat.com> adds:
sct> Hi, On Thu, 2004-10-07 at 11:12, Marcelo Tosatti wrote:
>> Oh yes, theres also the indirect blocks which we might need to read from >> disk.
sct> Right.
>> Now the question is, how strict should the O_NONBLOCK implementation be >> in reference to "not blocking" ?
sct> Well, I suspect that depends on the application. But if you've got an sct> app that really wants to make sure its hot path is as fast as possible sct> (eg. a high-throughput server multiplexing disk IO and networking sct> through a single event loop), then ideally the app would want to punt sct> any blocking disk IO to another thread.
sct> So it's a matter of significant extra programing for a small extra sct> reduction in app blocking potential.
sct> I think it's worth getting this right in the long term, though. sct> Getting readahead of indirect blocks right has other benefits too --- sct> eg. we may be able to fix the situation where we end up trying to read sct> indirect blocks before we've even submitted the IO for the previous sct> data blocks, breaking the IO pipeline ordering.
So for the short term, are you an advocate of the patch posted?
-Jeff - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |