On Thu, 17 Mar 2016 13:41:56 +0000 Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > On Thu, Mar 17, 2016 at 01:34:59PM +0000, Chris Wilson wrote: > > vmaps are temporary kernel mappings that may be of long duration. > > Reusing a vmap on an object is preferrable for a driver as the cost of > > setting up the vmap can otherwise dominate the operation on the object. > > However, the vmap address space is rather limited on 32bit systems and > > so we add a notification for vmap pressure in order for the driver to > > release any cached vmappings. > > > > The interface is styled after the oom-notifier where the callees are > > passed a pointer to an unsigned long counter for them to indicate if they > > have freed any space. > > > > v2: Guard the blocking notifier call with gfpflags_allow_blocking() > > > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > > Cc: David Rientjes <rientjes@xxxxxxxxxx> > > Cc: Roman Peniaev <r.peniaev@xxxxxxxxx> > > Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> > > Cc: linux-mm@xxxxxxxxx > > Cc: linux-kernel@xxxxxxxxxxxxxxx > > --- > > include/linux/vmalloc.h | 4 ++++ > > mm/vmalloc.c | 27 +++++++++++++++++++++++++++ > > 2 files changed, 31 insertions(+) > > > > diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h > > index d1f1d338af20..edd676b8e112 100644 > > --- a/include/linux/vmalloc.h > > +++ b/include/linux/vmalloc.h > > @@ -187,4 +187,8 @@ pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) > > #define VMALLOC_TOTAL 0UL > > #endif > > > > +struct notitifer_block; > Omg. /o\ Hah. Please move the forward declaration to top-of-file. This prevents people from later adding the same thing at line 100 - this has happened before. Apart from that, all looks OK to me - please merge it via the DRM tree if that is more convenient. -- 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>