ping... On 07/08/2013 06:38 PM, Gu Zheng wrote:
> Currently aio ring pages use get_user_pages() to allocate pages from movable > zone,as discussed in thread https://lkml.org/lkml/2012/11/29/69, it is easy to > pin user pages for a long time, which is fatal for memory hotplug/remove > framework. > > As Mel Gorman suggested, "Implement a callback for migration to unpin pages, > barrier operations until migration completes and pin the new pfns" can soloved > this issue. And the best palce to hold the callbacks is address space > operations > which can be found via page->mapping. > > But the current aio ring pages are anonymous pages, they don't have > address_space_operations, so we use an anon inode file as the aio ring file to > manage the aio ring pages, so that we can implement the callback and register > it > to page->mmapping->a_ops->migratepage. > > But there's a ploblem that all files created by anon_inode_getfile() share the > same inode, so mutil aio context will share the same aio ring pages, it'll > lead > to io events chaos. In order to solve this issus, we introduce a new fucntion > anon_inode_getfile_private() which is samilar to anon_inode_getfile(), but > each > new file has its own anon inode. > > This work is based on Benjamin's patch, > http://www.spinics.net/lists/linux-fsdevel/msg66014.html > > Gu Zheng (2): > fs/anon_inode: Introduce a new lib function > anon_inode_getfile_private() > fs/aio: Add support to aio ring pages migration > > fs/aio.c | 120 > +++++++++++++++++++++++++++++++++++++++---- > fs/anon_inodes.c | 66 +++++++++++++++++++++++ > include/linux/anon_inodes.h | 3 + > include/linux/migrate.h | 3 + > mm/migrate.c | 2 +- > 5 files changed, 182 insertions(+), 12 deletions(-) > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
