> From: Ric Mason [mailto:[email protected]] > Subject: Re: Questin about swap_slot free and invalidate page > > On 02/19/2013 11:27 PM, Dan Magenheimer wrote: > >> From: Ric Mason [mailto:[email protected]] > >>> Hugh is right that handling the possibility of duplicates is > >>> part of the tmem ABI. If there is any possibility of duplicates, > >>> the ABI defines how a backend must handle them to avoid data > >>> coherency issues. > >>> > >>> The kernel implements an in-kernel API which implements the tmem > >>> ABI. If the frontend and backend can always agree that duplicate > >> Which ABI in zcache implement that? > > https://oss.oracle.com/projects/tmem/dist/documentation/api/tmemspec-v001.pdf > > > > The in-kernel APIs are frontswap and cleancache. For more information about > > tmem, see http://lwn.net/Articles/454795/ > > But you mentioned that you have in-kernel API which can handle > duplicate. Do you mean zcache_cleancache/frontswap_put_page? I think > they just overwrite instead of optional flush the page on the > second(duplicate) put as mentioned in your tmemspec.
Maybe I am misunderstanding your question... The spec allows overwrite (and return success) OR flush the page (and return failure). Zcache does the latter (flush). The code that implements it is in tmem_put. -- 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/
