-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hello.
Tor at 1AEO wrote: > Unfortunate about the mimalloc 2.x segfaults on Alpine Linux with Tor. > Looking forward to your results with jemalloc, which also worked well > for us. I'm hesitant to switch to jemalloc on too many systems due to the poor security track record it has, although a random segfault with mimalloc does not give me the warm fuzzies, either. That is why I suggested to give mozjemalloc a try. It should be a drop-in replacement. > We haven’t researched root causes, allocator parameters, build-time > changes, or mozjemalloc yet. It would be great to see more relay > operators sharing more experiments and data points. There are a number of other memory allocators out there that you may want to test along with various tweaks. I would be interested to see how Daniel Micay's hardened_malloc runs on relays. I believe it is based on OpenBSD's omalloc and the Android Bionic libc's malloc. While it is a security-focused allocator, it actually *reduces* metadata overhead and fragmentation. Depending on the configuration, it may require a LOT of VMAs, thus increasing non-swappable slab pressure. > The memory savings have been substantial: roughly 200 relays now > consume ~300 GB total instead of ~1000 GB, which is a significant > operational cost difference. Most of my relays have 1-2 GB RAM, which seems to be the minimum that does not cause performance loss under memory pressure and can sustain 100 Mbps in each direction. In my case, the worst situation seems to be when so much non-swappable kernel memory is used (from the connection tracking table, socket structures, etc.) that a GFP_ATOMIC allocation fails, which locks the whole system up. Sadly, this happens even when there is plenty of swap remaining and while raising vm.min_free_kbytes helps somewhat, it's not a panacea. I suspect reduced userspace memory fragmentation would not help all that much in my particular instance, but I'm sure it's very useful on systems that have multiple relays running on them. Regards, forest -----BEGIN PGP SIGNATURE----- iHUEARYKAB0WIQQtr8ZXhq/o01Qf/pow+TRLM+X4xgUCaWNcqQAKCRAw+TRLM+X4 xsnyAQDKrQvG7Gj6gJ9ODw+GwyXELo3f3zK8ROzUx+6NCvvK5QD+Lsr2SbQxc5OE zCAlZkUcJ3GO3XgnIXNuRrn3M6myeQI= =ZrqW -----END PGP SIGNATURE----- _______________________________________________ tor-relays mailing list -- [email protected] To unsubscribe send an email to [email protected]
