On Wed, Oct 22, 2014 at 01:45:58PM +0200, Peter Zijlstra wrote: > On Wed, Oct 22, 2014 at 02:29:25PM +0300, Kirill A. Shutemov wrote: > > On Wed, Oct 22, 2014 at 12:34:49AM -0700, Davidlohr Bueso wrote: > > > On Mon, 2014-10-20 at 23:56 +0200, Peter Zijlstra wrote: > > > > Hi, > > > > > > > > I figured I'd give my 2010 speculative fault series another spin: > > > > > > > > https://lkml.org/lkml/2010/1/4/257 > > > > > > > > Since then I think many of the outstanding issues have changed sufficiently to > > > > warrant another go. In particular Al Viro's delayed fput seems to have made it > > > > entirely 'normal' to delay fput(). Lai Jiangshan's SRCU rewrite provided us > > > > with call_srcu() and my preemptible mmu_gather removed the TLB flushes from > > > > under the PTL. > > > > > > > > The code needs way more attention but builds a kernel and runs the > > > > micro-benchmark so I figured I'd post it before sinking more time into it. > > > > > > > > I realize the micro-bench is about as good as it gets for this series and not > > > > very realistic otherwise, but I think it does show the potential benefit the > > > > approach has. > > > > > > > > (patches go against .18-rc1+) > > > > > > I think patch 2/6 is borken: > > > > > > error: patch failed: mm/memory.c:2025 > > > error: mm/memory.c: patch does not apply > > > > > > and related, as you mention, I would very much welcome having the > > > introduction of 'struct faut_env' as a separate cleanup patch. May I > > > suggest renaming it to fault_cxt? > > > > What about extend start using 'struct vm_fault' earlier by stack? > > I'm not sure we should mix the environment for vm_ops::fault, which > acquires the page, and the fault path, which deals with changing the > PTE. Ideally we should not expose the page-table information to file > ops, its a layering violating if nothing else, drivers should not have > access to the page tables. We already have this for ->map_pages() :-P I have asked if it's considered layering violation and seems nobody cares... -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>