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| author | Nicholas Clark <nick@ccl4.org> | 2006-04-18 16:03:10 +0000 |
|---|---|---|
| committer | Nicholas Clark <nick@ccl4.org> | 2006-04-18 16:03:10 +0000 |
| commit | fee0a0f7c91325f3e0c5d30288c0696c82a600ae (patch) | |
| tree | b49667ba1295089892a3fc2f7fc077df8f459712 /pod | |
| parent | 3df43ef74691011f52cfd7284586a56044a8a4f2 (diff) | |
| download | perl-fee0a0f7c91325f3e0c5d30288c0696c82a600ae.tar.gz | |
Expand "am I hot or not" into a more general "Profile Perl" section.
p4raw-id: //depot/perl@27890
Diffstat (limited to 'pod')
| -rw-r--r-- | pod/perltodo.pod | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/pod/perltodo.pod b/pod/perltodo.pod index 3ff99421d3..c7dd23d781 100644 --- a/pod/perltodo.pod +++ b/pod/perltodo.pod @@ -368,17 +368,23 @@ become C<char>s. Finding variables to downsize coupled with rearrangement could shrink the interpreter structure; a size saving which is multiplied by the number of threads running. -=head2 am I hot or not? +=head2 Profile Perl - am I hot or not? -The idea of F<pp_hot.c> is that it contains the I<hot> ops, the ops that are -most commonly used. The idea is that by grouping them, their object code will -be adjacent in the executable, so they have a greater chance of already being -in the CPU cache (or swapped in) due to being near another op already in use. +The Perl source code is stable enough that it makes sense to profile it, +identify and optimise the hotspots. It would be good to measure the +performance of the Perl interpreter using free tools such as cachegrind, +gprof, and dtrace, and work to reduce the bottlenecks they reveal. + +As part of this, the idea of F<pp_hot.c> is that it contains the I<hot> ops, +the ops that are most commonly used. The idea is that by grouping them, their +object code will be adjacent in the executable, so they have a greater chance +of already being in the CPU cache (or swapped in) due to being near another op +already in use. Except that it's not clear if these really are the most commonly used ops. So -anyone feeling like exercising their skill with coverage and profiling tools -might want to determine what ops I<really> are the most commonly used. And in -turn suggest evictions and promotions to achieve a better F<pp_hot.c>. +as part of exercising your skills with coverage and profiling tools you might +want to determine what ops I<really> are the most commonly used. And in turn +suggest evictions and promotions to achieve a better F<pp_hot.c>. =head2 Shrink struct context |