Messages in this thread | | | Date | Wed, 22 Aug 2007 11:52:58 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: bug in migrate page |
| |
On Wed, 22 Aug 2007 10:08:09 +0800 Shaohua Li <shaohua.li@intel.com> wrote:
> commit dc386d4d1e98bb39fb967ee156cd456c802fc692 adds rcu_read_lock, but > some routines in the lock range might sleep (like lock_buffer, > aops->writepage), I saw a 'sleep in atomic' warning. It appears the > patch has several versions before. Doing rcu_read_lock in PageAnon > sounds break the case of PageAnon(page) && PageSwapCache(page), > as .writepage might be called. The dummy anon patch maybe is ok. >
Thank you for catching.
Maybe you're correct.
BTW, in PageAnon(page) && PageSwapCache(page) case, I can't find when .writepage is called. Could you explain ?
In my understanding,
rcu_read_lock() -> try_to_unmap() -> move_to_new_page() -> migrate_page() // swap has .migratepage member. -> migrate_page_move_mapping(). -> migrate_page_copy(). -> remove_migration_ptes().
At quick glance, above path has no writepage() ops. just replace swap's radix tree entry.
Thanks, -Kame
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |