On Fri, 12 Oct 2007 10:45:17 -0700 Suleiman Souhlal <[EMAIL PROTECTED]> wrote:
> > On Oct 12, 2007, at 7:58 AM, Peter Zijlstra wrote: > > > On Fri, 2007-10-12 at 07:53 -0700, Arjan van de Ven wrote: > >> On Fri, 12 Oct 2007 12:50:22 +0200 > >>>>> The pages will still be read-only due to dirty tracking, so the > >>>>> first write will still do page_mkwrite(). > >>>> > >>>> Which can SIGBUS, no? > >>> > >>> Sure, but that is no different than any other mmap'ed write. I'm > >>> not seeing how an mlocked region is special here. > >>> > >>> I agree it would be nice if mmap'ed writes would have better error > >>> reporting than SIGBUS, but such is life. > >> > >> well... there's another consideration > >> people use mlock() in cases where they don't want to go to the > >> filesystem for paging and stuff as well (think the various iscsi > >> daemons and other things that get in trouble).. those kind of uses > >> really use mlock to avoid > >> 1) IO to the filesystem > >> 2) Needing memory allocations for pagefault like things > >> at least for the more "hidden" cases... > >> > >> prefaulting everything ready pretty much gives them that... letting > >> things fault on demand... nicely breaks that. > > > > Non of that is changed. So I'm a little puzzled as to which side you > > argue. > > I think this might change the behavior in case you mlock sparse files. > I guess currently the holes disappear when you mlock them, but with > the patch the blocks wouldn't get allocated until they get written to. eh yeah I forgot to mention this was for the sparse case.... - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
