On Fri, Sep 09, 2011 at 09:00:08AM -0400, Christoph Hellwig wrote: > On Fri, Sep 09, 2011 at 12:00:47PM +0100, Mel Gorman wrote: > > Currently swapfiles are managed entirely by the core VM by using > > ->bmap to allocate space and write to the blocks directly. This > > patch adds address_space_operations methods that allow a filesystem > > to optionally control the swapfile. > > > > int swap_activate(struct file *); > > int swap_deactivate(struct file *); > > int swap_writepage(struct file *, struct page *, struct writeback_control *); > > int swap_readpage(struct file *, struct page *); > > Just as the last two dozen times this came up: > > NAK > > The right fix is to add a filesystem method to support direct-I/O on > arbitrary kernel pages, instead of letting the wap abstraction leak into > the filesystem. Ok. I confess I haven't investigated this direction at all yet. Is it correct that your previous objection was http://linux.derkeiler.com/Mailing-Lists/Kernel/2009-10/msg00455.html and the direct-IO patchset you were thinking of was http://copilotco.com/mail-archives/linux-kernel.2009/msg87176.html ? If so, are you suggesting that instead of swap_readpage and swap_writepage I look into what is required for swap to use ->readpage method and ->direct_IO aops? -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>