Hi. On Fri, 2007-02-09 at 17:03 -0500, Alan Stern wrote: > On Sat, 10 Feb 2007, Nigel Cunningham wrote: > > > Hi. > > > > On Fri, 2007-02-09 at 17:04 +0100, Oliver Neukum wrote: > > > Hi, > > > > > > can there be running aio requests if all tasks are frozen? > > > > Since tasks are frozen, no new aio requests would be submitted. We do a > > sync to ssek to complete existing requests; I haven't looked to see > > whether that would need extending to flush aio as well, but don't think > > that would be the case. Given everyone else's silence, so far, you might > > be better to ask the author(s) of the aio code. > > I believe Nigel is basically correct. However sync will only flush aio > for block devices. Other types of aio will remain active. > > aio callbacks are interrupt-driven and execute in a workqueue (see > fs/aio.c), and as far as I can tell that workqueue doesn't freeze. > Unless some general facility freezes all workqueues... Hmm. That applies to Raid, too? I've had some reports of raid i/o being caught in the BUG_ON() I have to catch I/O that shouldn't be happening, but haven't gotten around to looking at them yet. Regards, Nigel
