Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1356202

Re: [PATCH 1/3] pfn_t: Change the encoding

Show all headers | View raw

On Fri, Mar 11, 2016 at 1:13 PM, Matthew Wilcox
<matthew.r.wilcox@intel.com> wrote:
> By moving the flag bits to the bottom, we encourage commonality
> between SGs with pages and those using pfn_t.  We can also then insert
> a pfn_t into a radix tree, as it uses the same two bits for indirect &
> exceptional indicators.

It's not immediately clear to me what we gain with SG entry
commonality.  The down side is that we lose the property that
pfn_to_pfn_t() is a nop.  This was Dave's suggestion so that the
nominal case did not change the binary layout of a typical pfn.

Can we just bit swizzle a pfn_t on insertion/retrieval from the radix?

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 0/3] Make pfn_t suitable for placing in the radix tree Matthew Wilcox <matthew.r.wilcox@intel.com> - 2016-03-11 22:20 +0100
  [PATCH 3/3] pfn_t: New functions pfn_t_add and pfn_t_cmp Matthew Wilcox <matthew.r.wilcox@intel.com> - 2016-03-11 22:20 +0100
  [PATCH 1/3] pfn_t: Change the encoding Matthew Wilcox <matthew.r.wilcox@intel.com> - 2016-03-11 22:20 +0100
    Re: [PATCH 1/3] pfn_t: Change the encoding Dan Williams <dan.j.williams@intel.com> - 2016-03-11 22:50 +0100
      Re: [PATCH 1/3] pfn_t: Change the encoding Matthew Wilcox <willy@linux.intel.com> - 2016-03-12 19:40 +0100
        Re: [PATCH 1/3] pfn_t: Change the encoding Dan Williams <dan.j.williams@intel.com> - 2016-03-14 00:10 +0100
          Re: [PATCH 1/3] pfn_t: Change the encoding Matthew Wilcox <willy@linux.intel.com> - 2016-03-14 16:10 +0100

csiph-web