Re: syncing the disks when entering sleep

Rafael J. Wysocki
2010-02-10T18:42:43Z

On Wednesday 10 February 2010, Oliver Neukum wrote:
> Am Mittwoch, 10. Februar 2010 11:58:22 schrieb Rafael J. Wysocki:
> > On Wednesday 10 February 2010, Oliver Neukum wrote:
> > > Am Mittwoch, 10. Februar 2010 11:34:23 schrieb Rafael J. Wysocki:
> > > > Actually, doing the sync() in the kernel is a hack that we decided not to
> > > > remove just because the users space didin't do the right thing on some systems.
> > > > If the user space always synced disks before suspending, we wouldn't have to
> > > > do that in the kernel.
> > >
> > > If you sync in user space will you not have an inevitable race condition?
> >
> > Do you mean the race with applications that write to disks while the sustem is
> > suspending?
>
> Yes.

That would matter if sync meant mandatory flushing all data to the storage
medium, but it doesn't. From a filesystem point of view it's an advisory
thing, something like "I wish you flushed buffers right now".

Rafael