On Wed, Jun 5, 2019 at 2:11 AM Panu Matilainen <pmatilai@xxxxxxxxxx> wrote: > > On 6/5/19 12:53 AM, Chris Murphy wrote: > > At least for small files, and there are many in any distribution, > > using a dictionary very well could improve compression/decompression > > time, compression ratio, more than threads. Adding dictionary support > > would help all the single thread hardware, and even the builders when > > zstd -T0 option dictates there's only 1 or 2 threads available. On the > > generic sample set, it's functionally like getting 4 threads on speed, > > and even compression ratio goes up by ~3x. But I have no idea how that > > sample set compares to Fedora's files. > > > > Yes, but as I mentioned in another email, rpm doesn't compress the files > individually, it compresses them as one big continuous archive. The > dictionary is unlikely to help that (in my quick test yesterday it > actually made it worse) Sorry about that I missed it. The --long/windowLog option sounds interesting. I found this on HN today. While xz is not expressly being used within Fedora/Red Hat packaging in an archive context, it does seem to have quite a lot of other potential problems. But I have no idea what lurking liabilities zstd will have. http://lzip.nongnu.org/xz_inadequate.html Tangentially, I think there is room for improvement with LiveOS delivery, which right now is doing something pathological I haven't been able to figure out compared to other distro LiveOS's: 100% CPU usage reported by one of the /dev/loopN processes during startup and installation. And as it's a single thread, it's a bottleneck. Everytime I do an installation on any computer, fans go to the max. I don't know that this is xz related, but it might be perturbing things because decompression is so processor intensive. I'll start a separate thread. -- Chris Murphy _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
