2015-07-13 ì¤í 6:24ì Konstantin Khlebnikov ì´(ê°) ì´ ê¸: > On Mon, Jul 13, 2015 at 11:35 AM, Gioh Kim <gioh.kim at lge.com> wrote: >> From: Gioh Kim <gurugio at hanmail.net> >> >> 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 at gmail.com> > >> >> 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. >
Great! I'll do it and inform you the result in this week.
