Messages in this thread | | | Date | Sun, 23 Nov 2003 14:40:52 -0800 | From | Andrew Morton <> | Subject | Re: [RFC] Simplify node/zone portion of page->flags |
| |
Matthew Dobson <colpatch@us.ibm.com> wrote: > > Currently we keep track of a pages node & zone in the top 8 bits (on > 32-bit arches, 10 bits on 64-bit arches) of page->flags. We typically > do: node_num * MAX_NR_ZONES + zone_num = 'nodezone'. It's non-trivial > to break this 'nodezone' back into node and zone numbers. This patch > modifies the way we compute the index to be: (node_num << ZONE_SHIFT) | > zone_num. This makes it trivial to recover either the node or zone > number with a simple bitshift. There are many places in the kernel > where we do things like: page_zone(page)->zone_pgdat->node_id to > determine the node a page belongs to. With this patch we save several > pointer dereferences, and it boils down to shifting some bits.
This rather conflicts with the patch from Jesse which I have. Can you guys work that out and let me know when you're done?
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |