Created attachment 1516273 [details] Patch fixing missing accounting of top chunk glibc's malloc_info() function returns wrong numbers in most of the cases. In particular, the `rest` field is 0 most of the time, and inconsistent with malloc_stats(). I believe this bug was introduced in commit commit bb066545063246d6df186f5a5a61303c58c6547d Author: Ulrich Drepper <drepper> Date: Thu Apr 9 05:45:42 2009 +0000 * malloc/malloc.c (malloc_info): New function. when the implementation of malloc_info() was copy-pasted from mallinfo(), and that the two mallinfo() lines + avail = chunksize (ar_ptr->top); + nblocks = 1; /* top always exists */ were forgotten to be copy-pasted. I have attached a patch that fixes the issue.
Upstream bug: https://sourceware.org/bugzilla/show_bug.cgi?id=24026
Is it a bug positively? or have you just not send patch to upstream?
(In reply to baul from comment #3) > Is it a bug positively? or have you just not send patch to upstream? It's a bug. Fixed with this patch: commit b6d2c4475d5abc05dd009575b90556bdd3c78ad0 Author: Niklas Hamb�chen <mail> Date: Thu Aug 8 22:02:27 2019 +0200 malloc: Fix missing accounting of top chunk in malloc_info [BZ #24026] Fixes `<total type="rest" size="..."> incorrectly showing as 0 most of the time. The rest value being wrong is significant because to compute the actual amount of memory handed out via malloc, the user must subtract it from <system type="current" size="...">. That result being wrong makes investigating memory fragmentation issues like <https://bugzilla.redhat.com/show_bug.cgi?id=843478> close to impossible.
Already fixed in bug 1735747 in RHEL 8.2.0 as a last-minute addition.