On Fri, Oct 26, 2012 at 03:19:09AM -0700, Darrick J. Wong wrote: > Hi everyone, > > Are people still annoyed about writes taking unexpectedly long amounts of tme > due to the stable page write patchset? I'm guessing yes... I haven't heard anyone except th elunatic fringe complain recently... > I'm close to posting a patchset that (a) gates the wait_on_page_writeback calls > on a flag that you can set in the bdi to indicate that you need stable writes > (which blk_integrity_register will set); I'd prefer stable pages by default (e.g. btrfs needs it for sane data crc calculations), with an option to turn it off. > (b) (ab)uses a page flag bit (PG_slab) > to indicate that a page is actually being sent out to disk hardware; and (c) I don't think you can do that. You can send slab allocated memory to disk (e.g. kmalloc()d memory) and XFS definitely does that for sub-page sized metadata. I'm pretty sure that means the PG_slab flag is not available for (ab)use in the IO path.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
