On Mon, Jul 24, 2017 at 07:02:12PM -0400, Dennis Zhou wrote: > From: "Dennis Zhou (Facebook)" <dennisszhou@xxxxxxxxx> > > This patch introduces the bitmap metadata blocks and adds the skeleton > of the code that will be used to maintain these blocks. Each chunk's > bitmap is made up of full metadata blocks. These blocks maintain basic > metadata to help prevent scanning unnecssarily to update hints. Full > scanning methods are used for the skeleton and will be replaced in the > coming patches. A number of helper functions are added as well to do > conversion of pages to blocks and manage offsets. Comments will be > updated as the final version of each function is added. > > There exists a relationship between PAGE_SIZE, PCPU_BITMAP_BLOCK_SIZE, > the region size, and unit_size. Every chunk's region (including offsets) > is page aligned at the beginning to preserve alignment. The end is > aligned to LCM(PAGE_SIZE, PCPU_BITMAP_BLOCK_SIZE) to ensure that the end > can fit with the populated page map which is by page and every metadata > block is fully accounted for. The unit_size is already page aligned, but > must also be aligned with PCPU_BITMAP_BLOCK_SIZE to ensure full metadata > blocks. > > Signed-off-by: Dennis Zhou <dennisszhou@xxxxxxxxx> Reviewed-by: Josef Bacik <jbacik@xxxxxx> Thanks, Josef -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
