On Tue, 2007-10-30 at 13:54 -0400, Chris Mason wrote: > On Tue, 30 Oct 2007 10:27:04 -0800 > Badari Pulavarty <pbadari@xxxxxxxxxx> wrote: > > > Hi, > > > > While testing hotplug memory remove, I ran into this issue. Given a > > range of pages hotplug memory remove tries to migrate those pages. > > > > migrate_pages() keeps failing to migrate pages containing pagecache > > pages for reiserfs files. I noticed that reiserfs doesn't have > > ->migratepage() ops. So, fallback_migrate_page() code tries to > > do try_to_release_page(). try_to_release_page() fails to > > drop_buffers() since b_count == 1. Here is what my debug shows: > > > > migrate pages failed pfn 258111/flags 3f00000000801 > > bh c00000000b53f6e0 flags 110029 count 1 > > > > Any one know why the b_count == 1 and not getting dropped to zero ? > > If these are file data pages, the count is probably elevated as part of > the data=ordered tracking. You can verify this via b_private, or just > mount data=writeback to double check. Chris, That was my first assumption. But after looking at reiserfs_releasepage (), realized that it would do reiserfs_free_jh() and clears the b_private. I couldn't easily find out who has the ref. against this bh. bh c00000000bdaaf00 flags 110029 count 1 private 0 Thanks, Badari - 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
