Added note about bts/btr/btc causing bogus cache read counts.

Added to todo list note about files with > 65536 lines.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@175
This commit is contained in:
Nicholas Nethercote 2002-04-30 12:46:22 +00:00
parent ee24852e5a
commit bf347fb8e0
4 changed files with 36 additions and 0 deletions

View File

@ -2374,6 +2374,14 @@ Valgrind's cache profiling has a number of shortcomings:
<li>It doesn't account for cache misses not visible at the instruction level,
eg. those arising from TLB misses, or speculative execution.</li><p>
<li>The instructions <code>bts</code>, <code>btr</code> and <code>btc</code>
will incorrectly be counted as doing a data read if both the arguments
are registers, eg:
<blockquote><code>btsl %eax, %edx</code></blockquote>
This should only happen rarely.
</ul>
Another thing worth nothing is that results are very sensitive. Changing the
@ -2394,6 +2402,7 @@ hopefully they should be close enough to be useful.<p>
<li>Program start-up/shut-down calls a lot of functions that aren't
interesting and just complicate the output. Would be nice to exclude
these somehow.</li><p>
<li>Handle files with &gt;65535 lines</li><p>
</ul>
<hr width="100%">
</body>

View File

@ -2374,6 +2374,14 @@ Valgrind's cache profiling has a number of shortcomings:
<li>It doesn't account for cache misses not visible at the instruction level,
eg. those arising from TLB misses, or speculative execution.</li><p>
<li>The instructions <code>bts</code>, <code>btr</code> and <code>btc</code>
will incorrectly be counted as doing a data read if both the arguments
are registers, eg:
<blockquote><code>btsl %eax, %edx</code></blockquote>
This should only happen rarely.
</ul>
Another thing worth nothing is that results are very sensitive. Changing the
@ -2394,6 +2402,7 @@ hopefully they should be close enough to be useful.<p>
<li>Program start-up/shut-down calls a lot of functions that aren't
interesting and just complicate the output. Would be nice to exclude
these somehow.</li><p>
<li>Handle files with &gt;65535 lines</li><p>
</ul>
<hr width="100%">
</body>

View File

@ -2374,6 +2374,14 @@ Valgrind's cache profiling has a number of shortcomings:
<li>It doesn't account for cache misses not visible at the instruction level,
eg. those arising from TLB misses, or speculative execution.</li><p>
<li>The instructions <code>bts</code>, <code>btr</code> and <code>btc</code>
will incorrectly be counted as doing a data read if both the arguments
are registers, eg:
<blockquote><code>btsl %eax, %edx</code></blockquote>
This should only happen rarely.
</ul>
Another thing worth nothing is that results are very sensitive. Changing the
@ -2394,6 +2402,7 @@ hopefully they should be close enough to be useful.<p>
<li>Program start-up/shut-down calls a lot of functions that aren't
interesting and just complicate the output. Would be nice to exclude
these somehow.</li><p>
<li>Handle files with &gt;65535 lines</li><p>
</ul>
<hr width="100%">
</body>

View File

@ -2374,6 +2374,14 @@ Valgrind's cache profiling has a number of shortcomings:
<li>It doesn't account for cache misses not visible at the instruction level,
eg. those arising from TLB misses, or speculative execution.</li><p>
<li>The instructions <code>bts</code>, <code>btr</code> and <code>btc</code>
will incorrectly be counted as doing a data read if both the arguments
are registers, eg:
<blockquote><code>btsl %eax, %edx</code></blockquote>
This should only happen rarely.
</ul>
Another thing worth nothing is that results are very sensitive. Changing the
@ -2394,6 +2402,7 @@ hopefully they should be close enough to be useful.<p>
<li>Program start-up/shut-down calls a lot of functions that aren't
interesting and just complicate the output. Would be nice to exclude
these somehow.</li><p>
<li>Handle files with &gt;65535 lines</li><p>
</ul>
<hr width="100%">
</body>