From: Tim Peters <tim.peters@gmail.com>
Date: Tue, 7 Apr 2026 04:08:47 +0000 (-0500)
Subject: Note out-of-date obmalloc comments (#148149)
X-Git-Tag: v3.15.0a8~8
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3df0c4da4c502a4e26ed00468dd97aa50a3bb260;p=thirdparty%2FPython%2Fcpython.git

Note out-of-date obmalloc comments (#148149)

Vladimir's original overviews, from 1998, are still good, but going
on 30 years later details have changed. Note that, but rather try
to keep up with moving targets in a different file, point to
sys._debugmallocstats() as the sure way to discover precise current
details.

No code changes, just added a block comment.

Co-authored-by: Bartosz Sławecki <bartosz@ilikepython.com>
---

diff --git a/Include/internal/pycore_obmalloc.h b/Include/internal/pycore_obmalloc.h
index d4dbe541e6da..f6b4bd90a234 100644
--- a/Include/internal/pycore_obmalloc.h
+++ b/Include/internal/pycore_obmalloc.h
@@ -14,6 +14,12 @@ typedef unsigned int pymem_uint;  /* assuming >= 16 bits */
 #undef  uint
 #define uint pymem_uint
 
+/* NOTE: the following overviews were in the initial checkin, in 1998. In
+ * 2026, they're still helpful, but some details have changed. For example,
+ * we now use 32 size classes 16 bytes apart, and an arena is generally at
+ * least 1MB. Use sys._debugmallocstats() to see exact current details for
+ * the specific version of CPython used.
+ */
 
 /* An object allocator for Python.