On Thu, May 07, 2020 at 01:24:38PM +0200, David Hildenbrand wrote: > On 07.05.20 12:46, Michael S. Tsirkin wrote: > > On Thu, May 07, 2020 at 12:31:11PM +0200, David Hildenbrand wrote: > >> virtio-mem wants to offline and remove a memory block once it unplugged > >> all subblocks (e.g., using alloc_contig_range()). Let's provide > >> an interface to do that from a driver. virtio-mem already supports to > >> offline partially unplugged memory blocks. Offlining a fully unplugged > >> memory block will not require to migrate any pages. All unplugged > >> subblocks are PageOffline() and have a reference count of 0 - so > >> offlining code will simply skip them. > >> > >> All we need is an interface to offline and remove the memory from kernel > >> module context, where we don't have access to the memory block devices > >> (esp. find_memory_block() and device_offline()) and the device hotplug > >> lock. > >> > >> To keep things simple, allow to only work on a single memory block. > >> > >> Acked-by: Michal Hocko <mhocko@xxxxxxxx> > >> Tested-by: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx> > >> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > >> Cc: David Hildenbrand <david@xxxxxxxxxx> > >> Cc: Oscar Salvador <osalvador@xxxxxxxx> > >> Cc: Michal Hocko <mhocko@xxxxxxxx> > >> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> > >> Cc: Wei Yang <richard.weiyang@xxxxxxxxx> > >> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> > >> Cc: Qian Cai <cai@xxxxxx> > >> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> > > > > > > didn't you lose Andrew Morton's ack here? > > Yeah, thanks for noticing. > > > > >> --- > >> include/linux/memory_hotplug.h | 1 + > >> mm/memory_hotplug.c | 37 ++++++++++++++++++++++++++++++++++ > >> 2 files changed, 38 insertions(+) > > > > I get: > > > > error: sha1 information is lacking or useless (mm/memory_hotplug.c). > > error: could not build fake ancestor > > > > which version is this against? Pls post patches on top of some tag > > in Linus' tree if possible. > > As the cover states, latest linux-next. To be precise > > commit 6b43f715b6379433e8eb30aa9bcc99bd6a585f77 (tag: next-20200507, > next/master) > Author: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> > Date: Thu May 7 18:11:31 2020 +1000 > > Add linux-next specific files for 20200507 > Don't base on linux-next please. Generally base on the tree you are targeting, or Linus' tree. > -- > Thanks, > > David / dhildenb
