Update implementation details docs re: PTRDIFF_MAX.

Document that the maximum size class is limited by PTRDIFF_MAX, rather
than the full address space.  This reflects changes that were part of
0c516a00c4 (Make *allocx() size class
overflow behavior defined.).
This commit is contained in:
Jason Evans 2016-03-31 12:31:10 -07:00
parent a82070ef5f
commit b582d2ad94

View File

@ -540,8 +540,8 @@ for (i = 0; i < nbins; i++) {
are smaller than four times the page size, large size classes are smaller
than the chunk size (see the <link
linkend="opt.lg_chunk"><mallctl>opt.lg_chunk</mallctl></link> option), and
huge size classes extend from the chunk size up to one size class less than
the full address space size.</para>
huge size classes extend from the chunk size up to the largest size class
that does not exceed <constant>PTRDIFF_MAX</constant>.</para>
<para>Allocations are packed tightly together, which can be an issue for
multi-threaded applications. If you need to assure that allocations do not
@ -659,7 +659,7 @@ for (i = 0; i < nbins; i++) {
<entry>[1280 KiB, 1536 KiB, 1792 KiB]</entry>
</row>
<row>
<entry morerows="6">Huge</entry>
<entry morerows="8">Huge</entry>
<entry>256 KiB</entry>
<entry>[2 MiB]</entry>
</row>
@ -687,6 +687,14 @@ for (i = 0; i < nbins; i++) {
<entry>...</entry>
<entry>...</entry>
</row>
<row>
<entry>512 PiB</entry>
<entry>[2560 PiB, 3 EiB, 3584 PiB, 4 EiB]</entry>
</row>
<row>
<entry>1 EiB</entry>
<entry>[5 EiB, 6 EiB, 7 EiB]</entry>
</row>
</tbody>
</tgroup>
</table>