On Mon, Jul 13, 2015 at 11:35 AM, Gioh Kim <gioh.kim@xxxxxxx> wrote: > From: Gioh Kim <gurugio@xxxxxxxxxxx> > > Hello, > > This series try to enable migration of non-LRU pages, such as driver's page. > > My ARM-based platform occured severe fragmentation problem after long-term > (several days) test. Sometimes even order-3 page allocation failed. It has > memory size 512MB ~ 1024MB. 30% ~ 40% memory is consumed for graphic processing > and 20~30 memory is reserved for zram. > > I found that many pages of GPU driver and zram are non-movable pages. So I > reported Minchan Kim, the maintainer of zram, and he made the internal > compaction logic of zram. And I made the internal compaction of GPU driver. > > They reduced some fragmentation but they are not enough effective. > They are activated by its own interface, /sys, so they are not cooperative > with kernel compaction. If there is too much fragmentation and kernel starts > to compaction, zram and GPU driver cannot work with the kernel compaction. > > So I thought there needs a interface to combine driver and kernel compaction. > This patch adds a generic isolate/migrate/putback callbacks for page > address-space and a new interface to create anon-inode to manage > address_space_operation. The zram and GPU, and any other modules can create > anon_inode and register its own migration method. The kernel compaction can > call the registered migration when it does compaction. > > My GPU driver source is not in-kernel driver so that I apply the interface > into balloon driver. The balloon driver is already merged > into the kernel compaction as a corner-case. This patch have the balloon > driver migration be called by the generic interface. > > > This patch set combines 4 patches. > > 1. patch 1/4: get inode from anon_inodes > This patch adds new interface to create inode from anon_inodes. > > 2. patch 2/4: framework to isolate/migrate/putback page > Add isolatepage, putbackpage into address_space_operations > and wrapper function to call them. > > 3. patch 3/4: apply the framework into balloon driver > The balloon driver is applied into the framework. It gets a inode > from anon_inodes and register operations in the inode. > The kernel compaction calls generic interfaces, not balloon > driver interfaces. > Any other drivers can register operations via inode like this > to migrate it's pages. > > 4. patch 4/4: remove direct calling of migration of driver pages > Non-lru pages are also migrated with lru pages by move_to_new_page(). The whole patchset looks good. Reviewed-by: Konstantin Khlebnikov <koct9i@xxxxxxxxx> > > This patch set is tested: > - turn on Ubuntu 14.04 with 1G memory on qemu. > - do kernel building > - after several seconds check more than 512MB is used with free command > - command "balloon 512" in qemu monitor > - check hundreds MB of pages are migrated Another simple test is several instances of tools/testing/selftests/vm/transhuge-stress.c runnng in parallel with balloon inflating/deflating. (transparent huge pages must be enabled of course) That catched a lot of races in ballooning code. > > My thanks to Konstantin Khlebnikov for his reviews of the RFC patch set. > Most of the changes were based on his feedback. > > This patch-set is based on v4.1 > > > Gioh Kim (4): > fs/anon_inodes: new interface to create new inode > mm/compaction: enable mobile-page migration > mm/balloon: apply mobile page migratable into balloon > mm: remove direct calling of migration > > drivers/virtio/virtio_balloon.c | 3 ++ > fs/anon_inodes.c | 6 +++ > fs/proc/page.c | 3 ++ > include/linux/anon_inodes.h | 1 + > include/linux/balloon_compaction.h | 15 +++++-- > include/linux/compaction.h | 80 ++++++++++++++++++++++++++++++++++ > include/linux/fs.h | 2 + > include/linux/page-flags.h | 19 ++++++++ > include/uapi/linux/kernel-page-flags.h | 1 + > mm/balloon_compaction.c | 72 ++++++++++-------------------- > mm/compaction.c | 8 ++-- > mm/migrate.c | 24 +++------- > 12 files changed, 160 insertions(+), 74 deletions(-) > > -- > 2.1.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
