microsoft
mi_thread_stats_print_out shows incorrect values for Release builds
Hi, I'm using mimalloc 2.2.3 built through vcpkg on a C++ program running on Windows. I want to use mimalloc's per-thread stats to monitor my threads' memory consumption on a long-running program which is built in Release mode. However, when using mi_thread_stats_print_out I see the values are incorrect (i.e. much lower than they should be).
As an example, I have the following code:
#include <chrono>
#include <cstdio>
#include <thread>
#include <mimalloc.h>
#include <mimalloc-new-delete.h>
static void thread_fn_leak()
{
for (auto i = 0; i < 5; ++i)
{
std::this_thread::sleep_for(std::chrono::seconds(5));
new char[104857600];
mi_thread_stats_print_out(nullptr, nullptr);
puts("");
}
}
int main()
{
mi_version();
std::thread t(thread_fn_leak);
t.join();
return 0;
}
When built on Debug mode, the stats look correct:
heap stats: peak total current block total#
bin 1: 8 B 8 B 8 B 8 B 1 not all freed
bin 13: 160 B 160 B 160 B 160 B 1 not all freed
bin 28: 2.0 KiB 2.0 KiB 2.0 KiB 2.0 KiB 1 not all freed
bin 33: 5.0 KiB 5.0 KiB 5.0 KiB 5.0 KiB 1 not all freed
heap stats: peak total current block total#
binned: 7.1 Ki 7.1 Ki 7.1 Ki not all freed
huge: 520.0 Mi 520.0 Mi 520.0 Mi not all freed
total: 520.0 MiB 520.0 MiB 520.0 MiB
malloc req: 6.0 KiB
reserved: 0 0 0 ok
committed: 0 0 0 ok
reset: 0
purged: 0
touched: 520.4 MiB 520.4 MiB 520.4 MiB
segments: 6 6 6 not all freed
-abandoned: 0 0 0 ok
-cached: 0 0 0 ok
pages: 9 9 9 not all freed
-abandoned: 0 0 0 ok
-extended: 9
-retire: 0
arenas: 0
-rollback: 0
mmaps: 0
commits: 0
resets: 0
purges: 0
guarded: 0
threads: 0 0 0 ok
searches: 0.0 avg
numa nodes: 1
elapsed: 25.076 s
process: user: 0.000 s, system: 0.000 s, faults: 1638, rss: 6.0 MiB, commit: 574.5 MiB
However, when built on Release mode I see the following:
heap stats: peak total current block total#
reserved: 0 0 0 ok
committed: 0 0 0 ok
reset: 0
purged: 0
touched: 385.5 KiB 385.5 KiB 385.5 KiB
segments: 6 6 6 not all freed
-abandoned: 0 0 0 ok
-cached: 0 0 0 ok
pages: 0 0 0 ok
-abandoned: 0 0 0 ok
-extended: 0
-retire: 0
arenas: 0
-rollback: 0
mmaps: 0
commits: 0
resets: 0
purges: 0
guarded: 0
threads: 0 0 0 ok
searches: 0.0 avg
numa nodes: 1
elapsed: 25.054 s
process: user: 0.000 s, system: 0.000 s, faults: 1477, rss: 5.4 MiB, commit: 554.5 MiB
Here touched shows 385 KB when in reality the thread is allocating around 500 MB. This is correctly reported by the (presumably OS-provided) process stats, but I'd like to have to have thread-specific stats here too since my real program uses thread pools, etc.
Am I doing something wrong, or is this expected to work correctly only for Debug builds?
Thanks.
