Messages in this thread | | | Subject | Re: [PATCH] mm: avoid dirtying shared mappings on mlock | From | Peter Zijlstra <> | Date | Fri, 12 Oct 2007 16:58:25 +0200 |
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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. [unhandled content-type:application/pgp-signature] | |