Re: [patch] sys_sync livelock fix

[Jeff Garzik <jgarzik@mandrakesoft.com>]

Bill Davidsen wrote:
> 
> Alan and/or Linus:
> 
>   Am I misreading this or is the Linux implementation of sync() based on
> making the shutdown scripts pause until disk i/o is done? Because I don't
> think commercial unices work that way, I think they work as SuS
> specifies. More reason to rethink this in 2.4 as well as 2.5 and get the
> possible live lock out of the kernel.



I don't think SuSv2 can be any more clear than:

> The writing, although scheduled, is not necessarily complete
> upon return from sync().

Quoting from http://www.opengroup.org/onlinepubs/007908799/xsh/sync.html

As I mentioned in the other message, IMHO we need some way to introduce
a global system I/O barrier, and then wait for all I/O scheduled before
that barrier to complete.  My suggestion for naming was the "checkpoint"
system call.

	Jeff


-- 
Jeff Garzik      | "I went through my candy like hot oatmeal
Building 1024    |  through an internally-buttered weasel."
MandrakeSoft     |             - goats.com