Hi Tejun, On Wed, Sep 04, 2013 at 03:22:15PM -0400, Tejun Heo wrote: >Hello, > >On Tue, Aug 27, 2013 at 05:37:37PM +0800, Tang Chen wrote: >> 1. Make memblock be able to allocate memory from low address to high address. >> Also introduce low limit to prevent memblock allocating memory too low. >> >> 2. Improve init_mem_mapping() to support allocate page tables from low address >> to high address. >> >> 3. Introduce "movablenode" boot option to enable and disable this functionality. >> >> PS: Reordering of relocate_initrd() and reserve_crashkernel() has not been done >> yet. acpi_initrd_override() needs to access initrd with virtual address. So >> relocate_initrd() must be done before acpi_initrd_override(). > >I'm expectedly happier with this approach but some overall review >points. > >* I think patch splitting went a bit too far. e.g. it doesn't make > much sense or helps anything to split "introduction of a param" from > "the param doing something". > >* I think it's a lot more complex than necessary. Just implement a > single function - memblock_alloc_bottom_up(@start) where specifying > MEMBLOCK_ALLOC_ANYWHERE restores top down behavior and do > memblock_alloc_bottom_up(end_of_kernel) early during boot. If the > bottom up mode is set, just try allocating bottom up from the > specified address and if that fails do normal top down allocation. > No need to meddle with the callers. The only change necessary > (well, aside from the reordering) outside memblock is adding two > calls to the above function. > >* I don't think "order" is the right word here. "direction" probably > fits a lot better. What's the root reason memblock alloc from high to low? To reduce fragmentation or ... Regards, Wanpeng Li > >Thanks. > >-- >tejun > >-- >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> -- 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>